question

lawrence-craig avatar image
lawrence-craig asked

Leaving Lithium cycling unattended (long term storage)

Hi all.

I am putting my boat away for winter and have a question about my 12v LiFePO4 settings.

- The yard turns the shore power off at night, then back on in the morning

- I plan to run the Multiplus 3000 24/7 with a small dehumidifier on (should only draw 10% of battery capacity when running overnight)

As I understand it, you don't want to keep running the batteries up to 100%. How should I set my Multiplus to just charge up to 50%? Say around 13.2V? Is it possible?

One way I was thinking of doing this was setting the BMS (JK SmartBMS) charged voltage so it stops charging at 50% but then I am concerned of the BMS cycling on and off.

Multiplus-IILithium Battery
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2 Answers
kevgermany avatar image
kevgermany answered ·

It's a myth about keeping these batteries partly charged instead of fully charged. You need to regularly hit 100% so the BMS can balance the cells.

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lawrence-craig avatar image lawrence-craig commented ·
So you’d recommend just keep it as normal in that allow the multiplus to charge to 100% during day and let it draw over night?
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kevgermany avatar image kevgermany ♦♦ lawrence-craig commented ·
Yes, or just turn the multi on once a week.
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matt1309 avatar image
matt1309 answered ·

In ESS setting that would be easy but assuming you're mobile you dont have that so schedule charging isnt a feature you have access to.

Not sure if there's another assistant that makes this easy but here's my best guess at a solution without an assistant.

I personally wouldnt go the voltage route for LiFePO4 unless you're not too fussy on the actual SoC it's at (just not 100 or 0). Assuming you do care about soc and want it close to 50% i would use node red running on a gx device.

If soc > x {

Turn charging off on the multi/inverter only mode)

}


You could also get fancier with the criteria, with time of day etc.

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