#Best 9 volt battery charger how to

If a battery charger isn't marked as a smart charger or trickle charger, it’s likely to be a more basic model that pumps a constant electrical current through batteries until you unplug it. However, keeping them constantly topped up also increases the likelihood of overcharging. Ideally, the trickle charge is equal to the charge that the battery leaks away naturally, so they’re kept fully topped up - ready for when you want to use them. Trickle chargers are useful if your rechargeable batteries aren’t ‘low self-discharge’ models (which have technology to stop them leaking away their charge when not in use). This is because the time will vary depending on the battery’s capacity, chemistry and age, among other factors. This won’t necessarily prevent overcharging or undercharging, though. Some have timers, so they turn off automatically after a set period of time. These push a low ‘trickle’ charge through batteries for a long period of time. Smart battery chargers are usually the best choice for keeping rechargeable batteries in good shape, as they prevent overcharging, which can reduce battery lifetime. Smart battery chargers, also known as delta-V chargers, monitor the voltage levels in each battery and stop charging (or switch to a low trickle-charge setting) when they’re full. However, the worst AAA rechargeable batteries we've tested lose nearly 20% of their charge if you don't use them for 50 days.Ĭheck our independent rechargeable batteries reviews to find the best batteries for your device. The best AA rechargeable batteries last nearly eight hours on a single charge and won't leak away their charge between uses. Once you’ve worked out what type of battery charger you want, make sure you buy the best rechargeable batteries to put in it. But you’ll pay more for these extras, so it’s worth thinking about whether they’ll be useful to you.

#Best 9 volt battery charger how to

Below, we explain what you need to know about battery chargers - including how to get the best from your charger.Ī battery charger with lots of features, such as a charge indicator, super-fast charging or the ability to charge 9V batteries, might be tempting as it covers all possibilities. Do you want to buy a new battery charger? Whether it's your first time buying a charger or you're replacing an old one, it’s worth knowing what extra features are worth paying for.