OCC Forums » Systems and Maintenance » Electrical » Lithium Iron Phosphate Batteries

Lithium Iron Phosphate Batteries

PhilipH2 — Tue, 05 Dec 2023 10:29:51 GMT

Our batteries are reaching a stage where replacement will be needed shortly. Consequently we are thinking about LiFePO4 batteries which are lighter, smaller, don't require same capacity, can be discharged further and last longer but are a bit more costly. Does anyone have any experience or advice re these batteries?

RE: Lithium Iron Phosphate Batteries

Wild.Bird — Tue, 05 Dec 2023 10:29:51 GMT

+x[quote]

[b]SoggyPaws - 5 Dec 2023[/b]
+x[quote]

[b]Wild.Bird - 17 Sep 2023[/b]
Interesting reading all the comments on lithium.
I built my own 280Ah 24v ( equivalent to 560Ah at 12v) battery using CATL cells purchased in the USA. I had them shipped to Antigua.
I used a JK 200A BMS with 2A active balance.
The convertion to lithium has been a game changer for us.
The 720w of solar we have used to harvest circa 2kWh per day when connected to our lead domestic bank. That same solar now harvests over 3kWh per day. The simple fact with lithium is that you dont need to get the battery full every day to maximise its life like you do with lead. Infact, keeping the battery below 90% full, will lengthen the life of lithium. As a result, we can use more battery capacity and keep the lithium battery on bulk charge, rarely floating the battery.
We now do 95% of our cooking on an induction hob. We boil the kettle on the induction hob. We use the immersion heater for hot water and we make water with our 220v watermaker all through a 3000w low frequency inverter.
We added 4x50w flesible panels on a canvas backing that are our roving panels for when anchored. They fold up in to the space of a single 50w panel when not in use. With this additional 200w of solar we are averaging 3.6kWh per day of solar harvest. More than enough to run all our loads electrically.
Our propane consumption is now negligible. We only use the gas cooker at sea, when our portable hob is stowed.
With the increasing number of people moving to lithium there are a few things to note.
24v boats are ideal for lithium. The load limiting factor is the BMS. They are rated in amps. If you are a 24v boat, you half the amp draw off your 24v battery.
Two lithium batteries is the ideal number. This actually needs to match your load but 2 batteries is way better than 4 batteries.
When you install multiple batteries in series, it can be difficult to balance the batteries with each other. This can result in one battery being dominant and taking most of the load. It can cause battery shut down of the highest or lowest charged battery in extreme cases. Parallel is less of a problem but balancing can still be an issue.

I am currently building a second lithium battery of a smaller size. 105Ah. It will use the same JK BMS and it be wired in parallel to the existing 280Ah battery. This will give me resilience should one BMS fail. It will allow me to carry on whilst we replace a BMS, etc.
The additional capacity will allow us to get through a few cloudy days without having to resort to the diesel generator.

Don't under estimate how much rewiring you may need to do to accommodate lithium. There is no such thing as a drop in replacement battery.

Stay clear of cheap lithium batteries. It is far better to build your own with cells from a known source and a good BMS than buy something in a sealed box that you know nothing about. The cost of building your own battery is about half the cost of a cheap drop in lithium battery.
Building your own battery also allows you to install the battery in a ventilated battery box. If you sail in the tropics, heat is not your friend. Cooling drop in lithium batteries isnt possible. The BMS mosfets make considerable heat when charging and particularly discharging. This heat cannot escape a sealed box. By comparison, a diy battery can easily accommodate forced ventilation.
Lithium and solar were made for each other. Maximise your solar install.
Speak,to your insurance company. Mine were happy for me to install lithium

[/quote]

Tim,
Thanks for the description of your LFP install. It seems everyone does it differently. A couple of things to note.
Not all BMSs are internal Mosfet relay rated in amps. A number are external relay BMSs with few of the internal Mosfet BMS disadvantages you mention. We used a very well regarded ElectroDacus SBMS0 external relay BMS that does require more wiring, including separate relays for the various charging devices and loads that the BMS can control. These are commonly available up to about 500 amps each. Using an external relay BMS greatly expands the amps a BMS can control and without any internal heat issues.
One battery can reasonably be used for most installs requiring only one BMS instead of two or more batteries, each requiring a separate BMS and having the battery balancing problems you mention. If you are concerned about a rare cell failure just carry a spare. We do.
Insurance coverage is a big deal and may get more difficult in the future. Read your insurance policy for its current requirements, but be aware that they may change in the future. They are all different right now. However, the future may require compliance with recently developed ABYC or ISO standards so understanding those is important before starting an install.
We live on solar in the tropics, almost never having to resort to our alts or portable generator for charging. We designed our system for at least 3 days holdover with no charging. It doesn't get much better than silent auto charging all day.
And finally using electric for cooking is safer, more convenient and produces far less heat than using LPG. LFP makes that possible.
Dave McCampbell
SV Soggy Paws

[/quote]

Yes, well aware of relay based BMS. For us there was no need to go that route with the added complexity. On a 24v boat the FET based BMS is hardly stressed as our amps are so low. Now we have two batteries in parallel with their own BMS we have redundancy of two independent systems. We run the batteries in parallel but either battery can easily run the boat. We never see total loads above 100A but each battery has a 200A BMS with 2A active balancer.
My install is ABYC compliant and my insurance company are happy with lithium.
95% of our cooking is on our induction hob.
We rarely run the diesel genset now. I occasionally do it just to keep it moving but we have so much power that we just run off solar and a wind turbine.

Tim

RE: Lithium Iron Phosphate Batteries

SoggyPaws — Tue, 05 Dec 2023 03:36:21 GMT

+x[quote]

[b]Wild.Bird - 17 Sep 2023[/b]
Interesting reading all the comments on lithium.
I built my own 280Ah 24v ( equivalent to 560Ah at 12v) battery using CATL cells purchased in the USA. I had them shipped to Antigua.
I used a JK 200A BMS with 2A active balance.
The convertion to lithium has been a game changer for us.
The 720w of solar we have used to harvest circa 2kWh per day when connected to our lead domestic bank. That same solar now harvests over 3kWh per day. The simple fact with lithium is that you dont need to get the battery full every day to maximise its life like you do with lead. Infact, keeping the battery below 90% full, will lengthen the life of lithium. As a result, we can use more battery capacity and keep the lithium battery on bulk charge, rarely floating the battery.
We now do 95% of our cooking on an induction hob. We boil the kettle on the induction hob. We use the immersion heater for hot water and we make water with our 220v watermaker all through a 3000w low frequency inverter.
We added 4x50w flesible panels on a canvas backing that are our roving panels for when anchored. They fold up in to the space of a single 50w panel when not in use. With this additional 200w of solar we are averaging 3.6kWh per day of solar harvest. More than enough to run all our loads electrically.
Our propane consumption is now negligible. We only use the gas cooker at sea, when our portable hob is stowed.
With the increasing number of people moving to lithium there are a few things to note.
24v boats are ideal for lithium. The load limiting factor is the BMS. They are rated in amps. If you are a 24v boat, you half the amp draw off your 24v battery.
Two lithium batteries is the ideal number. This actually needs to match your load but 2 batteries is way better than 4 batteries.
When you install multiple batteries in series, it can be difficult to balance the batteries with each other. This can result in one battery being dominant and taking most of the load. It can cause battery shut down of the highest or lowest charged battery in extreme cases. Parallel is less of a problem but balancing can still be an issue.

I am currently building a second lithium battery of a smaller size. 105Ah. It will use the same JK BMS and it be wired in parallel to the existing 280Ah battery. This will give me resilience should one BMS fail. It will allow me to carry on whilst we replace a BMS, etc.
The additional capacity will allow us to get through a few cloudy days without having to resort to the diesel generator.

Don't under estimate how much rewiring you may need to do to accommodate lithium. There is no such thing as a drop in replacement battery.

Stay clear of cheap lithium batteries. It is far better to build your own with cells from a known source and a good BMS than buy something in a sealed box that you know nothing about. The cost of building your own battery is about half the cost of a cheap drop in lithium battery.
Building your own battery also allows you to install the battery in a ventilated battery box. If you sail in the tropics, heat is not your friend. Cooling drop in lithium batteries isnt possible. The BMS mosfets make considerable heat when charging and particularly discharging. This heat cannot escape a sealed box. By comparison, a diy battery can easily accommodate forced ventilation.
Lithium and solar were made for each other. Maximise your solar install.
Speak,to your insurance company. Mine were happy for me to install lithium

[/quote]

Tim,
Thanks for the description of your LFP install. It seems everyone does it differently. A couple of things to note.
Not all BMSs are internal Mosfet relay rated in amps. A number are external relay BMSs with few of the internal Mosfet BMS disadvantages you mention. We used a very well regarded ElectroDacus SBMS0 external relay BMS that does require more wiring, including separate relays for the various charging devices and loads that the BMS can control. These are commonly available up to about 500 amps each. Using an external relay BMS greatly expands the amps a BMS can control and without any internal heat issues.
One battery can reasonably be used for most installs requiring only one BMS instead of two or more batteries, each requiring a separate BMS and having the battery balancing problems you mention. If you are concerned about a rare cell failure just carry a spare. We do.
Insurance coverage is a big deal and may get more difficult in the future. Read your insurance policy for its current requirements, but be aware that they may change in the future. They are all different right now. However, the future may require compliance with recently developed ABYC or ISO standards so understanding those is important before starting an install.
We live on solar in the tropics, almost never having to resort to our alts or portable generator for charging. We designed our system for at least 3 days holdover with no charging. It doesn't get much better than silent auto charging all day.
And finally using electric for cooking is safer, more convenient and produces far less heat than using LPG. LFP makes that possible.
Dave McCampbell
SV Soggy Paws

RE: Lithium Iron Phosphate Batteries

SoggyPaws — Tue, 05 Dec 2023 02:54:03 GMT

+x[quote]

[b]Bill.Bowers - 28 Sep 2023[/b]
Hats off for this excellent thread mates!!!

Our 1996 J42 limped home from Newfoundland in 2022 with 4 terminal Gp27 100AH Lifeline AGMs..

So we have also taken on a year-long DIY LFP upgrade voyage in our side yard. Spent 9 months studying sources mentioned above and designing. We are going with a Victron Lynx Smart BMS Bus nannying 2 330Ah Victron Smart LFP batteries . Victron ATC and ATD smart relays. The 2 LFP's and their proper non-arc fuses fit under the nav seat where 3 AGMs lived. DC DC converter charges the Get Home Starter bank of 2 GP 27 new Gel batteries, Wakespeed 500 alternator regulator under DVCC control of the BMS. New Victron Inverter/shore charger. New Victron MPPT regulators. The key is an ElektroMaax 250A remote rectified GenMaax alternator. The rectifier diodes are in a fan cooled heat sinked aluminum fin case mounted in the oilskin hanging locker of the aft head It will have a separate T sensor for the Cerbo GX to monitor, The small frame rotor on our 47 HP turbo Yanmar will be downrated to deliver180A steady state output without needing thermal cutback.

We have labeled latched out means of cross connecting the LA bank to charging and loads, and reenabling the old Balmar MC616 regulator if the Victron BMS disconnects.

Cheers
Bill Bowers
SV ConverJence
[/quote]

Hi Bill. Good idea to switch to LFP and take your time with the research. Lots of Victron equipment in your build. Good stuff! Big alternator too. I didn't see any mention of solar, but maybe there's no sun up that far north. We survive on solar down here in the tropics. Let us know how it works out for you.

RE: Lithium Iron Phosphate Batteries

Bill.Bowers — Thu, 28 Sep 2023 00:17:46 GMT

Hats off for this excellent thread mates!!!

Our 1996 J42 limped home from Newfoundland in 2022 with 4 terminal Gp27 100AH Lifeline AGMs..

So we have also taken on a year-long DIY LFP upgrade voyage in our side yard. Spent 9 months studying sources mentioned above and designing. We are going with a Victron Lynx Smart BMS Bus nannying 2 330Ah Victron Smart LFP batteries . Victron ATC and ATD smart relays. The 2 LFP's and their proper non-arc fuses fit under the nav seat where 3 AGMs lived. DC DC converter charges the Get Home Starter bank of 2 GP 27 new Gel batteries, Wakespeed 500 alternator regulator under DVCC control of the BMS. New Victron Inverter/shore charger. New Victron MPPT regulators. The key is an ElektroMaax 250A remote rectified GenMaax alternator. The rectifier diodes are in a fan cooled heat sinked aluminum fin case mounted in the oilskin hanging locker of the aft head It will have a separate T sensor for the Cerbo GX to monitor, The small frame rotor on our 47 HP turbo Yanmar will be downrated to deliver180A steady state output without needing thermal cutback.

We have labeled latched out means of cross connecting the LA bank to charging and loads, and reenabling the old Balmar MC616 regulator if the Victron BMS disconnects.

Cheers
Bill Bowers
SV ConverJence

RE: Lithium Iron Phosphate Batteries

Wild.Bird — Wed, 20 Sep 2023 10:43:28 GMT

+x[quote]

[b]SoggyPaws - 20 Sep 2023[/b]
+x[quote]

[b]Wild.Bird - 17 Sep 2023[/b]
Interesting reading all the comments on lithium.
I built my own 280Ah 24v ( equivalent to 560Ah at 12v) battery using CATL cells purchased in the USA. I had them shipped to Antigua.
I used a JK 200A BMS with 2A active balance.
The convertion to lithium has been a game changer for us.
The 720w of solar we have used to harvest circa 2kWh per day when connected to our lead domestic bank. That same solar now harvests over 3kWh per day. The simple fact with lithium is that you dont need to get the battery full every day to maximise its life like you do with lead. Infact, keeping the battery below 90% full, will lengthen the life of lithium. As a result, we can use more battery capacity and keep the lithium battery on bulk charge, rarely floating the battery.
We now do 95% of our cooking on an induction hob. We boil the kettle on the induction hob. We use the immersion heater for hot water and we make water with our 220v watermaker all through a 3000w low frequency inverter.
We added 4x50w flesible panels on a canvas backing that are our roving panels for when anchored. They fold up in to the space of a single 50w panel when not in use. With this additional 200w of solar we are averaging 3.6kWh per day of solar harvest. More than enough to run all our loads electrically.
Our propane consumption is now negligible. We only use the gas cooker at sea, when our portable hob is stowed.
With the increasing number of people moving to lithium there are a few things to note.
24v boats are ideal for lithium. The load limiting factor is the BMS. They are rated in amps. If you are a 24v boat, you half the amp draw off your 24v battery.
Two lithium batteries is the ideal number. This actually needs to match your load but 2 batteries is way better than 4 batteries.
When you install multiple batteries in series, it can be difficult to balance the batteries with each other. This can result in one battery being dominant and taking most of the load. It can cause battery shut down of the highest or lowest charged battery in extreme cases. Parallel is less of a problem but balancing can still be an issue.

I am currently building a second lithium battery of a smaller size. 105Ah. It will use the same JK BMS and it be wired in parallel to the existing 280Ah battery. This will give me resilience should one BMS fail. It will allow me to carry on whilst we replace a BMS, etc.
The additional capacity will allow us to get through a few cloudy days without having to resort to the diesel generator.

Don't under estimate how much rewiring you may need to do to accommodate lithium. There is no such thing as a drop in replacement battery.

Stay clear of cheap lithium batteries. It is far better to build your own with cells from a known source and a good BMS than buy something in a sealed box that you know nothing about. The cost of building your own battery is about half the cost of a cheap drop in lithium battery.
Building your own battery also allows you to install the battery in a ventilated battery box. If you sail in the tropics, heat is not your friend. Cooling drop in lithium batteries isnt possible. The BMS mosfets make considerable heat when charging and particularly discharging. This heat cannot escape a sealed box. By comparison, a diy battery can easily accommodate forced ventilation.
Lithium and solar were made for each other. Maximise your solar install.
Speak,to your insurance company. Mine were happy for me to install lithium

[/quote]

Interesting comments on your system. Seems everyone's system ends up different. We ended up with 540 ahrs LFP and 800 watts of panels for 160 ahrs daily usage. Works very well here in the tropics of SE Asia. Good advice at the end, especially of using quality equipment; it does not have to be expensive. Enjoy your cruising.
[/quote]

Our average daily usage here in the Caribbean since I built the battery 4 months ago is 114Ah at 24v, so 228Ah at 12v equivalent.

RE: Lithium Iron Phosphate Batteries

SoggyPaws — Wed, 20 Sep 2023 07:34:18 GMT

+x[quote]

[b]Wild.Bird - 17 Sep 2023[/b]
Interesting reading all the comments on lithium.
I built my own 280Ah 24v ( equivalent to 560Ah at 12v) battery using CATL cells purchased in the USA. I had them shipped to Antigua.
I used a JK 200A BMS with 2A active balance.
The convertion to lithium has been a game changer for us.
The 720w of solar we have used to harvest circa 2kWh per day when connected to our lead domestic bank. That same solar now harvests over 3kWh per day. The simple fact with lithium is that you dont need to get the battery full every day to maximise its life like you do with lead. Infact, keeping the battery below 90% full, will lengthen the life of lithium. As a result, we can use more battery capacity and keep the lithium battery on bulk charge, rarely floating the battery.
We now do 95% of our cooking on an induction hob. We boil the kettle on the induction hob. We use the immersion heater for hot water and we make water with our 220v watermaker all through a 3000w low frequency inverter.
We added 4x50w flesible panels on a canvas backing that are our roving panels for when anchored. They fold up in to the space of a single 50w panel when not in use. With this additional 200w of solar we are averaging 3.6kWh per day of solar harvest. More than enough to run all our loads electrically.
Our propane consumption is now negligible. We only use the gas cooker at sea, when our portable hob is stowed.
With the increasing number of people moving to lithium there are a few things to note.
24v boats are ideal for lithium. The load limiting factor is the BMS. They are rated in amps. If you are a 24v boat, you half the amp draw off your 24v battery.
Two lithium batteries is the ideal number. This actually needs to match your load but 2 batteries is way better than 4 batteries.
When you install multiple batteries in series, it can be difficult to balance the batteries with each other. This can result in one battery being dominant and taking most of the load. It can cause battery shut down of the highest or lowest charged battery in extreme cases. Parallel is less of a problem but balancing can still be an issue.

I am currently building a second lithium battery of a smaller size. 105Ah. It will use the same JK BMS and it be wired in parallel to the existing 280Ah battery. This will give me resilience should one BMS fail. It will allow me to carry on whilst we replace a BMS, etc.
The additional capacity will allow us to get through a few cloudy days without having to resort to the diesel generator.

Don't under estimate how much rewiring you may need to do to accommodate lithium. There is no such thing as a drop in replacement battery.

Stay clear of cheap lithium batteries. It is far better to build your own with cells from a known source and a good BMS than buy something in a sealed box that you know nothing about. The cost of building your own battery is about half the cost of a cheap drop in lithium battery.
Building your own battery also allows you to install the battery in a ventilated battery box. If you sail in the tropics, heat is not your friend. Cooling drop in lithium batteries isnt possible. The BMS mosfets make considerable heat when charging and particularly discharging. This heat cannot escape a sealed box. By comparison, a diy battery can easily accommodate forced ventilation.
Lithium and solar were made for each other. Maximise your solar install.
Speak,to your insurance company. Mine were happy for me to install lithium

[/quote]

Interesting comments on your system. Seems everyone's system ends up different. We ended up with 540 ahrs LFP and 800 watts of panels for 160 ahrs daily usage. Works very well here in the tropics of SE Asia. Good advice at the end, especially of using quality equipment; it does not have to be expensive. Enjoy your cruising.

RE: Lithium Iron Phosphate Batteries

Wild.Bird — Mon, 18 Sep 2023 11:23:54 GMT

+x[quote]

[b]Simon Currin - 18 Sep 2023[/b]
Thank you very much for this write-up of your recent experience. We had some battery balancing issues which we eventually resolved with a battery balancer and some tweaks to the wiring. Well worth the effort though.

Simon

+x[quote]

[b]Wild.Bird - 17 Sep 2023[/b]
Interesting reading all the comments on lithium.
I built my own 280Ah 24v ( equivalent to 560Ah at 12v) battery using CATL cells purchased in the USA. I had them shipped to Antigua.
I used a JK 200A BMS with 2A active balance.
The convertion to lithium has been a game changer for us.
The 720w of solar we have used to harvest circa 2kWh per day when connected to our lead domestic bank. That same solar now harvests over 3kWh per day. The simple fact with lithium is that you dont need to get the battery full every day to maximise its life like you do with lead. Infact, keeping the battery below 90% full, will lengthen the life of lithium. As a result, we can use more battery capacity and keep the lithium battery on bulk charge, rarely floating the battery.
We now do 95% of our cooking on an induction hob. We boil the kettle on the induction hob. We use the immersion heater for hot water and we make water with our 220v watermaker all through a 3000w low frequency inverter.
We added 4x50w flesible panels on a canvas backing that are our roving panels for when anchored. They fold up in to the space of a single 50w panel when not in use. With this additional 200w of solar we are averaging 3.6kWh per day of solar harvest. More than enough to run all our loads electrically.
Our propane consumption is now negligible. We only use the gas cooker at sea, when our portable hob is stowed.
With the increasing number of people moving to lithium there are a few things to note.
24v boats are ideal for lithium. The load limiting factor is the BMS. They are rated in amps. If you are a 24v boat, you half the amp draw off your 24v battery.
Two lithium batteries is the ideal number. This actually needs to match your load but 2 batteries is way better than 4 batteries.
When you install multiple batteries in series, it can be difficult to balance the batteries with each other. This can result in one battery being dominant and taking most of the load. It can cause battery shut down of the highest or lowest charged battery in extreme cases. Parallel is less of a problem but balancing can still be an issue.

I am currently building a second lithium battery of a smaller size. 105Ah. It will use the same JK BMS and it be wired in parallel to the existing 280Ah battery. This will give me resilience should one BMS fail. It will allow me to carry on whilst we replace a BMS, etc.
The additional capacity will allow us to get through a few cloudy days without having to resort to the diesel generator.

Don't under estimate how much rewiring you may need to do to accommodate lithium. There is no such thing as a drop in replacement battery.

Stay clear of cheap lithium batteries. It is far better to build your own with cells from a known source and a good BMS than buy something in a sealed box that you know nothing about. The cost of building your own battery is about half the cost of a cheap drop in lithium battery.
Building your own battery also allows you to install the battery in a ventilated battery box. If you sail in the tropics, heat is not your friend. Cooling drop in lithium batteries isnt possible. The BMS mosfets make considerable heat when charging and particularly discharging. This heat cannot escape a sealed box. By comparison, a diy battery can easily accommodate forced ventilation.
Lithium and solar were made for each other. Maximise your solar install.
Speak,to your insurance company. Mine were happy for me to install lithium

[/quote]

[/quote]

We have been using Victron Battery balancers for several years on our lead batteries. We still use one on the pair of 12v starter batteries that are configured in series to give us 24v. They work really well. We actually ran different sized batteries for several years as we struggled to get new batteries in Panama. The balancer sorted it out

Tim
s/v Wild Bird

RE: Lithium Iron Phosphate Batteries

simoncurrin — Mon, 18 Sep 2023 07:00:34 GMT

Thank you very much for this write-up of your recent experience. We had some battery balancing issues which we eventually resolved with a battery balancer and some tweaks to the wiring. Well worth the effort though.

Simon

+x[quote]

[b]Wild.Bird - 17 Sep 2023[/b]
Interesting reading all the comments on lithium.
I built my own 280Ah 24v ( equivalent to 560Ah at 12v) battery using CATL cells purchased in the USA. I had them shipped to Antigua.
I used a JK 200A BMS with 2A active balance.
The convertion to lithium has been a game changer for us.
The 720w of solar we have used to harvest circa 2kWh per day when connected to our lead domestic bank. That same solar now harvests over 3kWh per day. The simple fact with lithium is that you dont need to get the battery full every day to maximise its life like you do with lead. Infact, keeping the battery below 90% full, will lengthen the life of lithium. As a result, we can use more battery capacity and keep the lithium battery on bulk charge, rarely floating the battery.
We now do 95% of our cooking on an induction hob. We boil the kettle on the induction hob. We use the immersion heater for hot water and we make water with our 220v watermaker all through a 3000w low frequency inverter.
We added 4x50w flesible panels on a canvas backing that are our roving panels for when anchored. They fold up in to the space of a single 50w panel when not in use. With this additional 200w of solar we are averaging 3.6kWh per day of solar harvest. More than enough to run all our loads electrically.
Our propane consumption is now negligible. We only use the gas cooker at sea, when our portable hob is stowed.
With the increasing number of people moving to lithium there are a few things to note.
24v boats are ideal for lithium. The load limiting factor is the BMS. They are rated in amps. If you are a 24v boat, you half the amp draw off your 24v battery.
Two lithium batteries is the ideal number. This actually needs to match your load but 2 batteries is way better than 4 batteries.
When you install multiple batteries in series, it can be difficult to balance the batteries with each other. This can result in one battery being dominant and taking most of the load. It can cause battery shut down of the highest or lowest charged battery in extreme cases. Parallel is less of a problem but balancing can still be an issue.

I am currently building a second lithium battery of a smaller size. 105Ah. It will use the same JK BMS and it be wired in parallel to the existing 280Ah battery. This will give me resilience should one BMS fail. It will allow me to carry on whilst we replace a BMS, etc.
The additional capacity will allow us to get through a few cloudy days without having to resort to the diesel generator.

Don't under estimate how much rewiring you may need to do to accommodate lithium. There is no such thing as a drop in replacement battery.

Stay clear of cheap lithium batteries. It is far better to build your own with cells from a known source and a good BMS than buy something in a sealed box that you know nothing about. The cost of building your own battery is about half the cost of a cheap drop in lithium battery.
Building your own battery also allows you to install the battery in a ventilated battery box. If you sail in the tropics, heat is not your friend. Cooling drop in lithium batteries isnt possible. The BMS mosfets make considerable heat when charging and particularly discharging. This heat cannot escape a sealed box. By comparison, a diy battery can easily accommodate forced ventilation.
Lithium and solar were made for each other. Maximise your solar install.
Speak,to your insurance company. Mine were happy for me to install lithium

[/quote]

RE: Lithium Iron Phosphate Batteries

Wild.Bird — Sun, 17 Sep 2023 12:01:24 GMT

Interesting reading all the comments on lithium.
I built my own 280Ah 24v ( equivalent to 560Ah at 12v) battery using CATL cells purchased in the USA. I had them shipped to Antigua.
I used a JK 200A BMS with 2A active balance.
The convertion to lithium has been a game changer for us.
The 720w of solar we have used to harvest circa 2kWh per day when connected to our lead domestic bank. That same solar now harvests over 3kWh per day. The simple fact with lithium is that you dont need to get the battery full every day to maximise its life like you do with lead. Infact, keeping the battery below 90% full, will lengthen the life of lithium. As a result, we can use more battery capacity and keep the lithium battery on bulk charge, rarely floating the battery.
We now do 95% of our cooking on an induction hob. We boil the kettle on the induction hob. We use the immersion heater for hot water and we make water with our 220v watermaker all through a 3000w low frequency inverter.
We added 4x50w flesible panels on a canvas backing that are our roving panels for when anchored. They fold up in to the space of a single 50w panel when not in use. With this additional 200w of solar we are averaging 3.6kWh per day of solar harvest. More than enough to run all our loads electrically.
Our propane consumption is now negligible. We only use the gas cooker at sea, when our portable hob is stowed.
With the increasing number of people moving to lithium there are a few things to note.
24v boats are ideal for lithium. The load limiting factor is the BMS. They are rated in amps. If you are a 24v boat, you half the amp draw off your 24v battery.
Two lithium batteries is the ideal number. This actually needs to match your load but 2 batteries is way better than 4 batteries.
When you install multiple batteries in series, it can be difficult to balance the batteries with each other. This can result in one battery being dominant and taking most of the load. It can cause battery shut down of the highest or lowest charged battery in extreme cases. Parallel is less of a problem but balancing can still be an issue.

I am currently building a second lithium battery of a smaller size. 105Ah. It will use the same JK BMS and it be wired in parallel to the existing 280Ah battery. This will give me resilience should one BMS fail. It will allow me to carry on whilst we replace a BMS, etc.
The additional capacity will allow us to get through a few cloudy days without having to resort to the diesel generator.

Don't under estimate how much rewiring you may need to do to accommodate lithium. There is no such thing as a drop in replacement battery.

Stay clear of cheap lithium batteries. It is far better to build your own with cells from a known source and a good BMS than buy something in a sealed box that you know nothing about. The cost of building your own battery is about half the cost of a cheap drop in lithium battery.
Building your own battery also allows you to install the battery in a ventilated battery box. If you sail in the tropics, heat is not your friend. Cooling drop in lithium batteries isnt possible. The BMS mosfets make considerable heat when charging and particularly discharging. This heat cannot escape a sealed box. By comparison, a diy battery can easily accommodate forced ventilation.
Lithium and solar were made for each other. Maximise your solar install.
Speak,to your insurance company. Mine were happy for me to install lithium

RE: Lithium Iron Phosphate Batteries

simoncurrin — Thu, 17 Nov 2022 13:26:35 GMT

It’s done! After 2 weeks of head scratching and digging deep into the piggy bank we now have 840 amp hours of LiFePO battery installed and a fully functioning charging system tailored to our boat’s needs and design. Thank you Hank George for your patience, oversight and ingenuity.

RE: Lithium Iron Phosphate Batteries

bbalme — Tue, 08 Nov 2022 06:14:48 GMT

Poor attempt at humor - Hank is a stand up guy and would only sell what he genuinely believes is required.

RE: Lithium Iron Phosphate Batteries

simoncurrin — Mon, 07 Nov 2022 15:36:57 GMT

No he’s not upselling. The bank is currently configured as 460 Amp hours at 24 volt so he is simply occupying the existing footprint of the cells we have. But I agree we should end up with a lot more useable power.
Simon

+x[quote]

[b]Bill Balme - 7 Nov 2022[/b]
Hank will steer you right. Please say hello to him from me.
That’s quite a lot of AH - we only have 600 and we’re a heavy consumer… I recon Hank is trying to up-sell you!!! ;-)
[/quote]

RE: Lithium Iron Phosphate Batteries

bbalme — Mon, 07 Nov 2022 15:20:01 GMT

Hank will steer you right. Please say hello to him from me.
That’s quite a lot of AH - we only have 600 and we’re a heavy consumer… I recon Hank is trying to up-sell you!!! ;-)

RE: Lithium Iron Phosphate Batteries

simoncurrin — Mon, 07 Nov 2022 15:01:46 GMT

Bill
The installation.has been designed here in White Stones by Hank George whom I am sure you know. I have no electrical expertise and have been trying to grapple with the science and Hank has been very patient. Most of the components are, or will be Victron, the batteries are Blue Heron 8 x105 amp hours and we are changing our alternator regular to a modern Balmar. Our wind generator regulator is 16 years old and cannot be programmed for lithiums and I believe we are having Victron DC / DC converter so that we can still use that.

I’ll post updates as the work happens. There are many new isolators and fuses going into our circuitry too. Here’s a picture of our shattered AGM.

Simon
[img=../Uploads/Images/c969b830-1913-4b52-9a86-6bc.jpeg]../Uploads/Images/53c17d9f-c5f1-4764-ba3d-4d2.jpeg[/img]

+x[quote]

[b]Bill Balme - 7 Nov 2022[/b]
What sort of system/components are you looking at Simon?

[/quote]

RE: Lithium Iron Phosphate Batteries

bbalme — Mon, 07 Nov 2022 14:38:57 GMT

What sort of system/components are you looking at Simon?

RE: Lithium Iron Phosphate Batteries

SoggyPaws — Mon, 07 Nov 2022 10:33:57 GMT

+x[quote]

[b]Simon Currin - 7 Nov 2022[/b]
I’ve been following this thread for ages and we had resolved to replace AGM’s with AGM’s. However, we have now been convinced to take the plunge and move to LiFePO. In preparation for the installers arrival I have burrowed deep into the bilges to expose the entire bank and have found one case split wide open and one blown. I expect the split one was a result of frost damage. No wonder we have been using the generator so much!Installation starts tomorrow. Simon
[/quote]

Hi Simon,

Great idea! It will really change your cruising life for the better for a long time to come. Hope you have done your homework so you can keep up with the installer's ideas. I'm happy to answer and questions or concerns based on our experience. Pls let us know how it all turns out.

Dave McCampbell
SV Soggy Paws

RE: Lithium Iron Phosphate Batteries

simoncurrin — Mon, 07 Nov 2022 02:44:20 GMT

I’ve been following this thread for ages and we had resolved to replace AGM’s with AGM’s. However, we have now been convinced to take the plunge and move to LiFePO. In preparation for the installers arrival I have burrowed deep into the bilges to expose the entire bank and have found one case split wide open and one blown. I expect the split one was a result of frost damage. No wonder we have been using the generator so much! Installation starts tomorrow. Simon

RE: Lithium Iron Phosphate Batteries

Sonia.Johal — Wed, 02 Nov 2022 12:34:18 GMT

LINK TO HYBRID LiPo BATTERY DATASHEET [img=../Uploads/Images/db72f073-101d-4f83-9b31-95c.jpeg]../Uploads/Images/8b399539-75b7-48ce-9d34-9d6.jpeg[/img] [img=../Uploads/Images/4b0f66a4-55e1-4f3a-8b4a-7c2.jpeg]../Uploads/Images/f0908a29-8385-4a42-9e87-6d4.jpeg[/img]

RE: Lithium Iron Phosphate Batteries

Sonia.Johal — Wed, 02 Nov 2022 12:30:38 GMT

HYBRID LITHIUM BATTERIES Many thanks Team OCC, I appreciate your comprehensive consideration and most useful responses, in advance of my purchase. For your further information, I attach the force4 chandlery link to these new batteries; https://www.force4.co.uk/item/BOS/LE300-Lithium-Extension-Battery-System/29WZ I’m most grateful for all your help and feedback, especially as my budget is tight and I endeavour to make use of my existing AGM battery bank. Best wishes and fair winds, Sonia SY Salacia

RE: Lithium Iron Phosphate Batteries

Dick — Wed, 02 Nov 2022 12:14:13 GMT

+x[quote]

[b]Stefan.Ecke - 2 Nov 2022[/b]
+x[quote]

[b]Dick - 1 Nov 2022[/b]
+x[quote]

[b]Sonia Johal - 1 Nov 2022[/b]
Thanks Stefan,That’s brilliant news, as these hybrid batteries are so much more cost effective than standard lithium phosphate batteries, as well as being safer than lithium ones.I shall stick to my plan and thanks so much for your kind reassurance.Best wishes and fair winds,SoniaSY Salacia
[/quote]

Hi Sonia and Stefan,
I hate to be a damp blanket, but I am not sure I would concur that any Lithium battery installation could (or should) be to the point where a skipper would call it “quite easy”. I invite others with lithium installs to weigh in.
I have been following lithium installs for a good while now and they have made significant progress, but I do not believe they are yet ready for plug ‘n play use. I know some of the “drop-in” lithium sales people would have it so, but I believe they are more interested in making sales than in a wise installation that is safe and reliable.
Firstly, A lithium install often demands a complete design and/or re-design of your vessel’s electrical system. This certainly involves every charging system, alternator and regulator, battery charger, solar regulator, etc. Wiring and fusing often need to be upgraded to deal with the increased amperage that can occur. And integrating the BMS (battery management system) with the various parts of the system to ensure safety and reliability can be quite challenging. There also needs to be plans to ensure mission critical systems (nav lights, GPS, etc.) are powered in case the lithium drop out in a load dump.
I also think at this time and anticipating a first long passage, that a skipper should be so well versed in lithium chemistry, installation management etc. that he/she could have done the install on their own, even if they chose someone else to do it (this is to facilitate trouble shooting when/if it is needed). I would also suggest reading the recent ABYC suggestions for lithium installations: I am not sure whether RCD/CE in the EU have suggested requirements as yet.
Again, I hope others comment.
My best, Dick Stevenson, s/v Alchemy

[/quote]

Thank you Dick, that you remember me why I hate forums. You always find somebody who write something negative without reading the question. Sonia ask something about the LE 300 from the company BOS. Not more. So, read and anderstand. Stefan
[/quote]

Hi Stefan,
I am sorry I offended you. That was not my intention, although I knew, as I said in the first sentence, that what I was writing might not be received comfortably.
If I missed something and went down a wrong pathway, then I would hope that you could gently re-direct me rather than using me as an example of what is wrong on forums. I would also hope that you, as a fellow member of OCC, would extend to me the presumption that I was writing in good faith and I would also hope that my writings in the Forum reflect that my interests are searching for best and safe practices for a widely wandering sailboat.
I stand by what I see as the present state of lithium battery installations for a boat that is widely wandering and where safety and reliability are paramount. I wrote what I wrote as one cruiser’s thoughts on a mission critical system. I did not condemn lithium; I know friends who have done installs that are safe and reliable, but none of them would have described the install as “quite easy”, although I recognize that you experienced it as such.
I was writing for someone who is not a seasoned sailor doing their first offshore passage. A vessel mid ocean should have, to my mind, the mission critical elements of their boat be gear be bullet-proof: that there is a history of field reports over time substantiating safety and reliability. Lithium is changing rapidly, but I do think that those wandering widely with lithium are still what I call early adapters. I have friends, very experienced skippers all, who have done this successfully and they have worked hard and long to make it work.
I suspect most boats will be lithium powered in the not-too-distant future and, as is still occurring, changing and evolving, safety and reliability will be established.
\My best, Dick Stevenson, s/v Alchemy

RE: Lithium Iron Phosphate Batteries

Stefan.Ecke — Wed, 02 Nov 2022 05:13:58 GMT

+x[quote]

[b]Dick - 1 Nov 2022[/b]
+x[quote]

[b]Sonia Johal - 1 Nov 2022[/b]
Thanks Stefan,That’s brilliant news, as these hybrid batteries are so much more cost effective than standard lithium phosphate batteries, as well as being safer than lithium ones.I shall stick to my plan and thanks so much for your kind reassurance.Best wishes and fair winds,SoniaSY Salacia
[/quote]

Hi Sonia and Stefan,
I hate to be a damp blanket, but I am not sure I would concur that any Lithium battery installation could (or should) be to the point where a skipper would call it “quite easy”. I invite others with lithium installs to weigh in.
I have been following lithium installs for a good while now and they have made significant progress, but I do not believe they are yet ready for plug ‘n play use. I know some of the “drop-in” lithium sales people would have it so, but I believe they are more interested in making sales than in a wise installation that is safe and reliable.
Firstly, A lithium install often demands a complete design and/or re-design of your vessel’s electrical system. This certainly involves every charging system, alternator and regulator, battery charger, solar regulator, etc. Wiring and fusing often need to be upgraded to deal with the increased amperage that can occur. And integrating the BMS (battery management system) with the various parts of the system to ensure safety and reliability can be quite challenging. There also needs to be plans to ensure mission critical systems (nav lights, GPS, etc.) are powered in case the lithium drop out in a load dump.
I also think at this time and anticipating a first long passage, that a skipper should be so well versed in lithium chemistry, installation management etc. that he/she could have done the install on their own, even if they chose someone else to do it (this is to facilitate trouble shooting when/if it is needed). I would also suggest reading the recent ABYC suggestions for lithium installations: I am not sure whether RCD/CE in the EU have suggested requirements as yet.
Again, I hope others comment.
My best, Dick Stevenson, s/v Alchemy

[/quote]

Thank you Dick, that you remember me why I hate forums. You always find somebody who write something negative without reading the question. Sonia ask something about the LE 300 from the company BOS. Not more. So, read and anderstand. Stefan

RE: Lithium Iron Phosphate Batteries

SoggyPaws — Wed, 02 Nov 2022 01:37:09 GMT

+x[quote]

[b]Dick - 1 Nov 2022[/b]
+x[quote]

[b]Sonia Johal - 1 Nov 2022[/b]
Thanks Stefan,That’s brilliant news, as these hybrid batteries are so much more cost effective than standard lithium phosphate batteries, as well as being safer than lithium ones.I shall stick to my plan and thanks so much for your kind reassurance.Best wishes and fair winds,SoniaSY Salacia
[/quote]

Hi Sonia and Stefan,
I hate to be a damp blanket, but I am not sure I would concur that any Lithium battery installation could (or should) be to the point where a skipper would call it “quite easy”. I invite others with lithium installs to weigh in.
I have been following lithium installs for a good while now and they have made significant progress, but I do not believe they are yet ready for plug ‘n play use. I know some of the “drop-in” lithium sales people would have it so, but I believe they are more interested in making sales than in a wise installation that is safe and reliable.
Firstly, A lithium install often demands a complete design and/or re-design of your vessel’s electrical system. This certainly involves every charging system, alternator and regulator, battery charger, solar regulator, etc. Wiring and fusing often need to be upgraded to deal with the increased amperage that can occur. And integrating the BMS (battery management system) with the various parts of the system to ensure safety and reliability can be quite challenging. There also needs to be plans to ensure mission critical systems (nav lights, GPS, etc.) are powered in case the lithium drop out in a load dump.
I also think at this time and anticipating a first long passage, that a skipper should be so well versed in lithium chemistry, installation management etc. that he/she could have done the install on their own, even if they chose someone else to do it (this is to facilitate trouble shooting when/if it is needed). I would also suggest reading the recent ABYC suggestions for lithium installations: I am not sure whether RCD/CE in the EU have suggested requirements as yet.
Again, I hope others comment.
My best, Dick Stevenson, s/v Alchemy

[/quote]

Hi Sonia,

I agree with all Dick has said above, especially that the boat owner should be fully involved, if not do the work himself, on any marine lithium/LFP system. Installing a LFP battery system is certainly not an easy project if you want a 'best practice' installation that you can use for long term overseas cruising. There are certainly shortcuts that can be taken, including using an installer that will most likely want to do a preassembled/drop in system. It is somewhat easier and more lucrative for him to do, since the battery box and BMS installation are already done. But there is much more to a good installation than that! And with a drop in system you lose some of the safety features and the ability to make repairs of a DIY system. If you are not familiar with what they are look at some of the posts above or read the Marine How To and Nordkyn websites that describe the differences.

You should know that the LFP market is very competitive right now. Some dealers have made claims about their products that just are not true. And there is a huge range of equipment options, some much better than others. I seriously doubt that the Hymer batteries you mention are "safer and more cost effective" than a properly done quality DIY system. Every drop in system I have ever looked at is just the opposite. Can you give us a link and some details as to why you think that? What will this install cost you, and what spares and tools will you carry in case of a problem later on? It is a worthwhile discussion for this forum.

I am not familiar with the Hymer hybrid battery system, however, I do know how a hybrid system is supposed to work. We have been using a quality DIY LFP system we installed ourselves for over 2 years now. It took us almost a year to do the research, order the equipment and do the install. There are some significant problems with some preassembled/drop in systems. Best you research this carefully rather than just believe a dealers' hype. A good place to do that is on the FB Group 'Lithium Batteries on a Boat'. There are some really knowledgeable long term users and experts on that forum that can better advise you. There are also a couple of trusted very detailed internet website resources mentioned in my first para above that would be worth reading.

Finally, Flying Fish will be running an article with our thoughts on doing a LFP install this month. This is not an easy project to get a handle on, but because of the cost and complexity it is best to not take shortcuts and try to get it right the first time. That takes time and study.

Dave McCampbell
SV Soggy Paws
In Indonesia

RE: Lithium Iron Phosphate Batteries

Dick — Tue, 01 Nov 2022 23:18:45 GMT

+x[quote]

[b]Sonia Johal - 1 Nov 2022[/b]
Thanks Stefan,That’s brilliant news, as these hybrid batteries are so much more cost effective than standard lithium phosphate batteries, as well as being safer than lithium ones.I shall stick to my plan and thanks so much for your kind reassurance.Best wishes and fair winds,SoniaSY Salacia
[/quote]

Hi Sonia and Stefan,
I hate to be a damp blanket, but I am not sure I would concur that any Lithium battery installation could (or should) be to the point where a skipper would call it “quite easy”. I invite others with lithium installs to weigh in.
I have been following lithium installs for a good while now and they have made significant progress, but I do not believe they are yet ready for plug ‘n play use. I know some of the “drop-in” lithium sales people would have it so, but I believe they are more interested in making sales than in a wise installation that is safe and reliable.
Firstly, A lithium install often demands a complete design and/or re-design of your vessel’s electrical system. This certainly involves every charging system, alternator and regulator, battery charger, solar regulator, etc. Wiring and fusing often need to be upgraded to deal with the increased amperage that can occur. And integrating the BMS (battery management system) with the various parts of the system to ensure safety and reliability can be quite challenging. There also needs to be plans to ensure mission critical systems (nav lights, GPS, etc.) are powered in case the lithium drop out in a load dump.
I also think at this time and anticipating a first long passage, that a skipper should be so well versed in lithium chemistry, installation management etc. that he/she could have done the install on their own, even if they chose someone else to do it (this is to facilitate trouble shooting when/if it is needed). I would also suggest reading the recent ABYC suggestions for lithium installations: I am not sure whether RCD/CE in the EU have suggested requirements as yet.
Again, I hope others comment.
My best, Dick Stevenson, s/v Alchemy

RE: Lithium Iron Phosphate Batteries

Sonia.Johal — Tue, 01 Nov 2022 17:30:10 GMT

Thanks Stefan, That’s brilliant news, as these hybrid batteries are so much more cost effective than standard lithium phosphate batteries, as well as being safer than lithium ones. I shall stick to my plan and thanks so much for your kind reassurance. Best wishes and fair winds, Sonia SY Salacia