Discussion in 'General Electronics Chat' started by Dr.killjoy, Dec 25, 2015.
I have a couple 18650 cells that need to be charged .. Does anyone know a good charging circuit ??
I'm using this one to charge my battery, but i believe it can only charge one battery at a time http://www.buildcircuit.com/how-to-...ithium-battery-charging-board-charger-module/
My first go at lithium charging was the battery for a Nikon camera that I didn't have the charger for - the charging control from an E-cigarette did the job, but it look a long time. AFAIK: some E-cigs use a replaceable 18650 and you can buy the charger to go with the kit - but you have to shop around to avoid getting ripped off.
My own DIY charger started off as a very simple TL431 shunt regulator and current limiting resistor. This can be boosted by adding a PNP emitter follower in the manner of a Sziklai pair - its advisable to feed the battery via a Shottky-barrier diode in case the TL431 fails short circuit. The voltage has to be calibrated accurately and the SB diode Vf taken into account.
Either add a timed shutdown, or make sure you don't leave it charging more than 48h.