TeenPower 12/20V Max Battery Charger Replacement for Dewalt DCB102 Compatible with 12V 20V Max Lithium Battery DCB124 DCB203 DCB204 DCB606, 2-Port Simultaneous Charging

Got a pair of batteries and purchased this to go with them. It appears to be good quality and charged both batteries quickly. Functions well and a good value for the money.

I know this is a knockoff, but so long as it is electrically designed reasonably, I don't care. The internal design literally duplicates the charging circuitry for the two batteries, so charging with one battery cannot affect the charging of another battery. The charging circuitry is essentially an isolated DC-to-DC converter, stepping down high-voltage to low-voltage. The high-voltage input comes from a full-bridge rectifier. Feedback to the high high-voltage side is through some opto-couplers. The circuit is reasonably efficient, but the greatest amount of heat loss is through the diode, which has a 0.3V forward drop. It would have been nice if it they had use a synchronous designed. 20V DeWalt batteries are essentially a dumb 5S lithium battery pack. Each of the individual cell lines is connected to a controller chip, which implies that it has the ability to monitor each cell to prevent overcharging. This is important as many other cheap chargers do not monitor each cell, which is extremely dangerous. There also appears to be some passive cell-balancing circuitry, but it's extremely low wattage. The charger controller IC is unfortunately deliberately unmarked, so I can't look up the specs. It draws 0.3W idle. It draws about 20W charging a single 12V battery (3S). It draws about 33W charging a single 20V battery (5S). When fully charged, it charges 20V batteries to 20.75V, which within the max voltage of a 5S Li-ion pack, but pushing it very close.

Great charger for DEWALT batteries. It's great one can charge two batteries t the same time, which is quite common if you own few of DEWALT cordless tools.

It works great

I think it's ok. I only used it once to charge my battories. WARNING it's not maid in America

It charges like it's supposed to i read some reviews saying it isn't a rapid charger....... but it works great for me

Very light and cheap feeling and far bulkier than needed. The left indicator light didn’t work right out of the box. Still tried to charge a battery on both sides. Only the ride side charged the battery. Charges far slower than my dewalt charger. The fit is very tight, have to really push to get the batteries to seat properly. Defective so returned.

Great product great price fast shipping, im happy