Review on ⚡ Universal 6 Bay 18650 Battery Charger - Wall Charger for 3.7v Lithium Rechargeable Batteries: Compatible with 18650, 26650, 14500, 16340(RCR123), 10440, 17670, 18490, 17500, and 17335 Lithium Batteries by Lori Sanders

You get what you pay for. I knew I would proceed with the purchase and that's what I got. Cheap charger for my 18650 batteries. According to the description it has a maximum output of 18W with a charging output of 300mA per battery, which is what you get if you even get that much. With 6 batteries in the charger, the charging capacity is less than 1 ampere per battery. DO NOT LEAVE CONNECTED OVERNIGHT, or when away from home, unless you are in a safe place in case of an outage/fire. EXTREMELY SLOW, EXTREMELY! 10 hours - 14 hours to charge 6 batteries from 3.3V to 4.2V. If you charge anything below 3V, it will take 14 hours or more. ATTENTION! The lights will not turn green to indicate a full charge. You should still check with a multimeter or briefly disconnect the battery from the charging contact to see if the indicator turns green on reconnection. When not enabled, it seems like they just keep loading. I left the batteries on to test this and see if it eventually turns green and stops charging when the batteries are fully charged. It didn't, it just kept charging until I finally removed them (with a couple of tries), the batteries kept charging even at up to 4.36+ (even after taking a break). The charger says it's putting out 4.2V, but that's obviously well beyond that. This is terrible for battery health and longevity. Maybe even very dangerous if he doesn't stop. It's unknown if it will stop charging and supplying power when the green light comes on. I've continued to use it, but only when I can keep a close eye on it. It takes more than a day to charge 4-6 batteries while checking them regularly with a multimeter after charging them for 8-11 hours (depending on how many batteries you charge) and continue checking every hour to check the to protect batteries from dangerous overcharging or damage. . It performs its main task and charges the batteries. Don't expect overcharge protection. There are no working indicators to let you know the cells are charged and have reached 4.2V. You must be patient. And don't leave your charger plugged in or unattended overnight. I highly recommend spending $10-15 more for a better/safer charger that doesn't take a week to charge 24-30 batteries.