problematic battery configuration?

[clockwork247]

I'm working with some 3.7V 18650, and I have to ask this question.

A lot of time people would built a 9-10S pack for 36V.

However my cheap old balance charger can only do 6S max. to get a 9-10S i would have to pay more (I payed 25~ per 80W balance charger).

Can I do 3X 12V pack? say 3-4S, and put them in a series to get 36V? I can see the usefulness in this as I have other devices that uses 12V, so if I ever need 12V juice, i just grab a pack and go, at the same time, it lets me charge 3 packs individually, I can get 3 chargers and get over 200W of charging power.

Thoughts?

 

[docnjoj]

Sure you can charge 3x4S packs in parallel, then run them in series. The problem is the 80 watt charger will take a while to charge them. the other problem is that changing from parallel to series could cause difficulty if you put them in the wrong order. Yes it can be done but much better to simply buy a Thunder 12S charger. It is less than 100 bucks. That makes charging easy and fast and you can still break up the packs to 4S packs and charge anything.
otherDoc

 

[clockwork247]

I see, this is true, I've burnt a few 18650 charger board by flipping the battery lol. I'll take a look into the Thunder 12S charger.

 

[dogman dan]

Even if you do use the 12s charger, it can be handy at times to have a pack that can become a large 12v pack.

I'm not a pack builder, but if I ever do I'm definitely doing 12v sections.