Hello guys,
I am working on a project in which I will use a big lithium-ion battery pack (36V 11Ah 396Wh). I want to be able to charge the pack with a solar panel (10-25W). However you can't just connect a 12V solar panel to a 10S battery. I know that I would have to make a BMS in order to charge the battery correctly. However, I was wondering if I could just use the charger plug and hook that one up to 42V, the charger only has 5 pins going to the pack which let me to believe that the charger just provides 42V and that the BMS is located in the cell itself. But 1: I'm not 100% sure if im correct and 2: I don't know the pinout of the charger plug.

Here are the Model number of the charger and battery:
Battery XWD-BL07
Charger: MDA11542002000

Gustav

 

A simple solution would be to use an inverter to make 120V AC for the charger. They're pretty inexpensive for low wattage. It wouldn't be the most efficient option, just the easiest and probably cheapest. Note that the charger is capable of 84W charging and your panel can't keep up with that. So I'm not sure what the charger output would be when its supply voltage falls.

I don't think it's a good idea to supply direct 42V to your battery pack. The charger monitors cell voltage and possibly temperature and probably is not a constant 42V output. I could be wrong, but it would be risky in my opinion.