Possible Causes for NiMh Batteries Losing Charge

NiMh batteries are very popular today for their ability to replace regular purchasing of alkaline batteries. However, you can run into problems with your NiMh batteries not fully charging, draining faster than they should, or even not charging at all. Information on possible causes and even a few fixes are covered below.

NiMh Batteries not Charging at All

Before immediately assuming the problem is in the batteries, make sure that they are seated properly in the charger. Also, make sure that there is no dust or debris on the connectors that might otherwise interfere with running current. Also, if a second charger is available, you can try charging on that one to see if your other charger is the culprit and in need of replacing.

Assuming that the batteries are the problem though, there are two possibilities if they aren’t charging at all. The first (and vastly more common) is that the batteries have been damaged in some way and simply aren’t functioning properly. Like any battery, they have internal components that can suffer from defects or be damaged from being dropped on a hard surface or any number of other issues. Even if your batteries still charge okay after something like a hard fall, you may want to replace them anyway, as they could later develop problems such as leaks.

Another rare problem that can occur is that, when batteries are allowed to be completely drained to zero charge, there is a risk of causing the batteries to reverse voltage. If this happens, they won’t be able to accept a charge. This can be prevented by charging up your batteries regularly before they are depleted, which will increase the life of the battery in general.

NiMh Batteries not Fully Charging

Occasionally, this can be caused by defective or damaged batteries, but generally this is a sign of “old age” for your batteries. All rechargeable batteries, no matter how high quality they are, will lose their ability to fully charge over time, and will eventually need to replaced.

However, if your batteries are relatively new, another cause for them not charging all the way is that they were not allowed to fully charge to begin with. By not allowing them to fully charge the first time they are put on a charger, you may be reducing their charge capacity severely right away.

NiMh Battery Draining Faster than Normal

Many people actually mistake a reduced total charge for a charge draining faster than normal. This may seem like a meaningless distinction, but by knowing that your batteries are actually suffering from not fully charging, you can more accurately diagnose the problem and the solution. However, in this particular case, it is likely a problem of reduced charge from old age and will simply need to be replaced.

Occasionally, and this is especially if you notice them draining faster than expected right off the bat, the problem may simply be poor quality batteries. Remember, as with many products with so many competing brands, you get what you pay for with rechargeable batteries.