The most common models charge both AA and AAA batteries, with some product lines extending the range of supported batteries to include D-cell batteries as well. Some can do both AA and AAA sizes at the same time. Since regular alkaline batteries can’t be recharged, most chargers (for example: SUNJACK USB BATTERY CHARGER ) come with a number of batteries that are designed to be recharged. If you choose a model that doesn’t, you’ll need to purchase your own rechargeable batteries separately.
Some of the best batteries chargers have quick-charge features, which can give you a quick burst of power in a matter of 15 minutes, so you can quickly power a device, albeit for a short period of time. A quick charge feature doesn’t power the battery to full charge, only a percentage. While such a feature is convenient, the majority of products offer standard charge times of between four to six hours.
Safety Features
Look for models with features designed to increase safety. Many models can detect when the recharging batteries are overheating and will automatically turn off before causing any damage. Most include an internal timer so they turn off when the batteries are done recharging. Furthermore, nearly all modern battery chargers can recognize when regular alkaline batteries are inserted, which means they will not initiate a charge of the non-rechargeable batteries.
Convenience Features
Chargers come in a range of sizes. Some recharge as few as two or four batteries, and others can manage 10 or more at once. If you need your battery charger to be portable, your best bet will be one that chargers fewer at a time, as these generally have a more compact design. Most models are designed to work with AA and AAA batteries, since those are the most common, but many have adapters or features that also let you charge C, D or 9V batteries. You can also find models that include an adapter so you can charge batteries in your car as you travel.
Help & Support
Battery chargers are relatively simple to use, but manufacturers do offer information online as well as support via email and phone, so there are resources if you run into any issues. A good warranty is also something you’ll want to pay attention to, as it can be an indication of how the company stands behind its products. Not all battery charger manufacturers offer a warranty, but among those that do, the length and terms vary. We’ve seen warranties range from one year to a lifetime of coverage.