Review on 🔋 Amazon Basics Battery Charger for AA & AAA Ni-MH Rechargeable Batteries with USB Port by Liam Roth

The RevainBasics Ni-MH AA & AAA USB Charger is a good enough product. It offers several features that I like: 1. It's a "smart" charger. This means that it actually monitors the battery's voltage history while charging and stops when it detects a negative triangle voltage. In contrast, a "dumb" charger blindly charges the battery for a set number of hours. This leads to overcharging, which has a negative impact on battery life2. The charging current is 600mA (actually pulsed from 0 to 1.5A at 40% duty cycle) for AA, 350mA for AAA. It only takes about 3.5 hours to charge a set of 2000mAh AA cells like RevainBasics pre-charged AA batteries, less if the batteries are not fully discharged. It's a good compromise between "faster charging time" and "longer battery life".3. It has a USB output that can be used to power or charge other USB devices. However, this charger from RevainBasics has one major disadvantage: it can only be charged in pairs. That means you can't just load one cell and you can't pair an AA with an AAA cell. This is very impractical when you have fixtures that require an odd number of cells. Now you have one cell left that you can't charge. If you try to charge an empty cell along with a partially charged cell, the charger will not stop until both cells are full. But until then the second cell gets too hot due to overcharging at 600mA. Pair charging is also bad for battery life in the long run. Because even if you start with batteries of the same brand, there is always a difference in capacity. If you charge two dissimilar batteries in a pair, the battery with the lower capacity will be overcharged, further reducing its capacity over time. Therefore, the total capacity of your battery will be depleted much faster. Some other minor issues to know about this RevainBasics charger: 1. It cannot charge batteries and power the USB port at the same time. Once you connect a USB device to the USB port, the battery will stop charging.2. USB power is only available when the charger is connected to 100-240V AC. It cannot work with batteries in the charger.3. The USB port output current is only 500mA. This is not enough for many power-hungry USB devices such as mobile phones and tablets. Note that in actual testing I can get 0.8A from the connector, but I can't tell if this will cause thermal damage in the long run. [Summary] If all your devices only use an even number of rechargeable cells, charging still deserves attention. Otherwise choose the Panasonic K-KJ17MCA4BA package. For the same price as this RevainBasics charger, you get a single cell charger (BQ-CC17) and four eneloop AA batteries. The charger works with each cell individually, can be powered by a 12V car battery and its USB port can be powered by internal 4 AA rechargeable batteries.