Hey, i came across this earlier... I dont even know what brought me to it, but anyway, its how to build a lipo charger for just a few bucks, and some electrical skill. Cheap enough for the cheapest of people! It doesn't balance, per se, but it charges each cell indevidually to 4.2v, so in the end they are balanced!
If it charges each cell individually, then the current would be limited to ~2A simply because the wire and connectors would introduce voltage drops at higher currents.
Building a CC/CV lipo charger really isn't all that difficult. What makes them complex/expensive is the switching PS (allows them to use 12v input but output anything really), the ability to select profiles through firmware, and the error checks for safety.
A DIY charger is fine for experienced people, but I sure wouldn't want someone who doesn't understand what lipos are about to use something like this.
Ah, one of the old parallel charger designs! Several years ago I had a lot of fun reading up on various DIY electronics threads on RC Groups, for things like DIY chargers, DIY balancers, DIY Lipo alarms, DIY UBECs, etc. I built all of those too, but only one of these projects proved useful: the DIY Lipo alarm. It was designed to work with 2s or 3s (different resistor values for each) and is very small, maybe 1/2" cubed. My Nomadio React is using the 2s Lipo alarm since the radio circuitry is powered by 5v UBEC and I can't tell what voltage the battery is at.
It's really fun stuff, especially learning to read the schematics.
SH Z-Car, Custom Crawler, 8s Savage, 12s XTM XLB 1/7 buggy, 4wd 4-link rear/IFS Pro4 truck, Custom Hyper 10 Short Course, Belt-Drive Mammoth ST 1/8 truggy, 4s 17.5 MM Pro HPI Blitz