I'm new to Lithium batteries!

[bgallinger]

I love the lithium batteries. I have 3 x 100Ah Enerwatt batteries with a Balmar SG 200 battery monitor.
What would be the lowest value of SOC or voltage before I get busy to re-charge the batteries?

Cheers!

[mbartosch]

Uh, that would be the lowest SoC you are comfortable with. Personally, at anchor or moored I‘d not go below 15 %SoC, on a passage I tend to recharge at 35 % SoC for safety reasons.
This question indicates „lead acid“ thinking. Not necessary with LiFePO4, just use them.

[bgallinger]

Originally Posted by mbartosch

Uh, that would be the lowest SoC you are comfortable with. Personally, at anchor or moored I‘d not go below 15 %SoC, on a passage I tend to recharge at 35 % SoC for safety reasons.
This question indicates „lead acid“ thinking. Not necessary with LiFePO4, just use them.

Thanks. I was thinking 25% would be the lowest acceptable level before re-charging

[mbartosch]

Taking the batteries down to less than about 20% SoC will have a very slight effect on the longevity of the bank, but IMO this is negligible. Keeping them at high SoC (> 80 %) for prolonged times is much worse.

In practice, lowest acceptable SoC on LiFePO4 is more a question of preference and of course safety considerations rather than a technical rule that should be obeyed.
You will likely replace the bank due to technology improvements rather than bank „health“ status if you just use it and follow the simple rules:
Don’t overcharge, stop charging when full, don’t keep it at high SoC for prolonged time, don’t discharge to 0 % (< 2.8 V Vpc), store and isolate bank at about 50 % SoC for prolonged absence.

[Nicholson58]

Originally Posted by bgallinger

I love the lithium batteries. I have 3 x 100Ah Enerwatt batteries with a Balmar SG 200 battery monitor.
What would be the lowest value of SOC or voltage before I get busy to re-charge the batteries?

Cheers!

The best primmer I know of

https://marinehowto.com/lifepo4-batteries-on-boats/

[goboatingnow]

Good primer , has a bit of an issue with FET power switches that’s a little hard to understand but otherwise not bad.