I recently built a DIY solar system for my barn.

[dcozz]

I do not use the barn on a daily basis, thus the battery depletes very little each day. Should I allow the solar panels to recharge the lithium batteries every day and keep them topped off, or let the batteries drain down and recharge once a week?

 

[timselectric]

Kept full is fine. Just don't overcharge.

 

[wheelman55]

Interesting situation. If you can plan ahead as to when you’ll use power in the barn, you can let the batteries sit at 60% SOC. Then let the batteries come to full charge the day before you use the barn.

Otherwise just use the power as you wish, when you wish, and don’t sweat it.

FYI. Lithium batteries last longest when stored at 60% and in a cool space.

Have fun with your solar!

 

[dcozz]

Kept full is fine. Just don't overcharge.

The charge controller should take care of that, as well as the batteries own BMS, right?

 

[timselectric]

The charge controller should take care of that, as well as the batteries own BMS, right?

Yes, if set correctly.