Charge van power bank with portable battery

[Altide8]

Hey everyone,

I have a large LiFePO4 power bank in my van. It does well, but I had an idea for those rainy and overcast weeks. I have another power bank with about 50ah LiFePO4. It’s in a tool box and very portable. I can easily charge it in my house or where ever. Does anyone do something similar or know of an effective way to charge my house battery in the van. Also my configuration is 4s. I run an sbms 40 in the van.

 

[snoobler]

This simple DC-DC converter:

https://www.amazon.com/Automatic-Converter-10A-Regulator-Waterproof/dp/B089M5KYZM

Will take 8-40V input and output 13.8V @ 10A. This would make a good low current charger

 

[Altide8]

This simple DC-DC converter:

https://www.amazon.com/Automatic-Converter-10A-Regulator-Waterproof/dp/B089M5KYZM

Will take 8-40V input and output 13.8V @ 10A. This would make a good low current charger

I was actually looking at something very similar on amazon last night. Thanks for the confirmation.

 

[snoobler]

In retrospect, the only concern I have is if the portable battery has its own BMS that will protect the cells.

 

[Altide8]

In retrospect, the only concern I have is if the portable battery has its own BMS that will protect the cells.

It does. It’s actually two 25ah packs. Each pack has a bms then they are in parallel. I know there is some debate about what is best. I like that I can easily separate the two packs and have protection.

 

[snoobler]

The debate is really about preferences. More individual batteries with their own BMS adds cost and redundancy. Whatever works for you.