LiFePO4

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   Hi I managed to kill my AGM service batteries (2x160 Ah) in just under 3 years. Probably mostly due to not disconnecting them  in the first winter, and thus they were left discharged for a long time. Not proud of that, being an Electronic engineer, but my excuse is that it was overwhelming to get a completely new boat delivered and getting to know all systems while also building a house.
I also abused them over the summer this year with using my thrusters a lot sailing through the 59 locks on the Gota Canal in Sweden. Every time they are used the thruster chargers kicks in with a fairly high load.
Anyways... they are dead and gone. 
So what to do? I decided on a boxed LiFePO4 solution with built in BMS, which easily fitted in and I only had to move one support and it was fitted. Beside the upfront cost it makes sense in so many ways:
Handles many more cycles
Cheaper in the long run
Can handle high loads
higher capacity with less weight and size.
BMS with bluetooth to monitor load and capacity
etc etc

Further to this i had the following considerations and subsequent decisions:

I Disconnected the connection to the alternator by removing the 125A ANL fuse on the busbar. I will use a Renogy 60A DC/DC charger from the engine battery/Alternator, which will be controlled to charge by the already fitted Whisperpower battery combiner, which will be used in its alternative ability to detect when the alternator is generating power. I spend a lot of time on this as i was eager to yield the full 150A potential of the alternator, but the risk of overheating it finally made me go for the more sensible converter.  The advantage (and challenge) with LiFePO4 is that it absorbs the full load.
I am currently using the MasterVolt 50A charger with a standard AGM profile, which seems to hit the charge levels nicely. I do plan on getting a MasterBus interface to I can reprogram the charger to a custom profile with the right bulk and absorption levels, and get rid of of the float voltage. 
It is super nice to now have a reliable and trustworthy powerbank of 384 Ah usable capacity (80% of 480Ah) over 160 Ah from the AGM's (50% of 320AH)
/Anders - VIND

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Vind Members Profile Send Private Message Find Members Posts Add to Buddy List Lieutenant Joined: 06 August 2022 Location: Aarhus, Denmark Status: Offline Points: 39	Post Options Post Reply Quote Vind Report Post Thanks(0) Quote Reply Topic: LiFePO4 Posted: 29 August 2023 at 21:10
	Hi I managed to kill my AGM service batteries (2x160 Ah) in just under 3 years. Probably mostly due to not disconnecting them in the first winter, and thus they were left discharged for a long time. Not proud of that, being an Electronic engineer, but my excuse is that it was overwhelming to get a completely new boat delivered and getting to know all systems while also building a house. I also abused them over the summer this year with using my thrusters a lot sailing through the 59 locks on the Gota Canal in Sweden. Every time they are used the thruster chargers kicks in with a fairly high load. Anyways... they are dead and gone. So what to do? I decided on a boxed LiFePO4 solution with built in BMS, which easily fitted in and I only had to move one support and it was fitted. Beside the upfront cost it makes sense in so many ways: Handles many more cycles Cheaper in the long run Can handle high loads higher capacity with less weight and size. BMS with bluetooth to monitor load and capacity etc etc Further to this i had the following considerations and subsequent decisions: I Disconnected the connection to the alternator by removing the 125A ANL fuse on the busbar. I will use a Renogy 60A DC/DC charger from the engine battery/Alternator, which will be controlled to charge by the already fitted Whisperpower battery combiner, which will be used in its alternative ability to detect when the alternator is generating power. I spend a lot of time on this as i was eager to yield the full 150A potential of the alternator, but the risk of overheating it finally made me go for the more sensible converter. The advantage (and challenge) with LiFePO4 is that it absorbs the full load. I am currently using the MasterVolt 50A charger with a standard AGM profile, which seems to hit the charge levels nicely. I do plan on getting a MasterBus interface to I can reprogram the charger to a custom profile with the right bulk and absorption levels, and get rid of of the float voltage. It is super nice to now have a reliable and trustworthy powerbank of 384 Ah usable capacity (80% of 480Ah) over 160 Ah from the AGM's (50% of 320AH) /Anders - VIND

S&J Members Profile Send Private Message Find Members Posts Add to Buddy List Admiral Joined: 30 August 2014 Location: Perth WA / Med Status: Offline Points: 1371	Post Options Post Reply Quote S&J Report Post Thanks(0) Quote Reply Posted: 29 August 2023 at 21:23
	I used to disconnect my batteries over the winter on my 385. The first years were in the Baltic, so at least 8 months. I totally disconnected the cables from the batteries. Always close to fully charged on return. I was always careful not to discharge to more than 75% SOC, although there were inevitably times when I went lower. Batteries still good after 6 years. I wish that Lithium had been an option when I ordered the 458 in 2020. Makes so much morse sense. I would definitely swap when my current AGM bank need replacement.
	H458 #159 Primal Mediterranean cruising

Vind Members Profile Send Private Message Find Members Posts Add to Buddy List Lieutenant Joined: 06 August 2022 Location: Aarhus, Denmark Status: Offline Points: 39	Post Options Post Reply Quote Vind Report Post Thanks(0) Quote Reply Posted: 29 August 2023 at 21:37
	G'day That's what I should have done, but I didn't know better then. On the other hand, it wouldn't have given me the opportunity for new toys if I hadn't been a fool ;-) Edited by Vind - 29 August 2023 at 21:39



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