Lithium Battery Maintenance Charger

[lifeofreilly57]

Greetings
I posted in the technical section, but this section gets more traffic.
I'm looking for a maintenance charger for my lithium batteries, I have two 300 amp hour batteries to maintain.
When I installed them in the Caribbean I had no intention of returning to a cold climate, unfortunately a health related issue finds us back in the balmy climate of Northeast US, the batteries have no internal heating, so they need to be removed during the winter layup.
Any suggestions would be appreciated. Amazon is not trustworthy in this situation since half the suggestions are paid advertising, and most of the others are Amazon products, their ratings are not to be trusted.

[goboatingnow]

Originally Posted by lifeofreilly57

Greetings

I posted in the technical section, but this section gets more traffic.

I'm looking for a maintenance charger for my lithium batteries, I have two 300 amp hour batteries to maintain.

When I installed them in the Caribbean I had no intention of returning to a cold climate, unfortunately a health related issue finds us back in the balmy climate of Northeast US, the batteries have no internal heating, so they need to be removed during the winter layup.

Any suggestions would be appreciated. Amazon is not trustworthy in this situation since half the suggestions are paid advertising, and most of the others are Amazon products, their ratings are not to be trusted.

Did you mean an unattended over winter charger etc. what’s the expected temp range. Are you looking for something at home

By and large onve charged lithiums can be left for months and months once there’s no loads

[lifeofreilly57]

Originally Posted by goboatingnow

Did you mean an unattended over winter charger etc. what’s the expected temp range. Are you looking for something at home

By and large onve charged lithiums can be left for months and months once there’s no loads

Yes, I'm looking for a winter storage maintenance charger for my batteries at my home. Although they can hold a charge for months it'll be 6 months til the boat goes back.
Too expensive to let them die.

[s/v Jedi]

Originally Posted by lifeofreilly57

Yes, I'm looking for a winter storage maintenance charger for my batteries at my home. Although they can hold a charge for months it'll be 6 months til the boat goes back.
Too expensive to let them die.

You don’t need that because the self discharge rate is less than 3% per month. So after 6 months they are less than 20% down and I think it will be less than 10%.

[Ween]

What Jedi said. I bought 2 300Ah kilovault LiFePO4 batteries, charged them up and ended up having to store them a year. They were down less than 25% over that time period.

[maine-cruiser]

I haul out in Boston for the winter and bring my LiFePo batteries down to about 60% SOC and disconnect them. They will drop about .02 volts over 5 months.

Bill

[PaulCrawhorn]

So long as your decent quality LFP cells are

100% isolated from parasitic loads - especially monitoring gear, the BMS etc

and discharged to around 3.2Vpc

They are just fine stored like that for a few months or even years.

Unattended charging / discharging would be very risky, use cheap lead for that.