How to Fix Rechargeable Batteries That Won’t Hold a Charge

Having rechargeable batteries is great but sometimes, they cause trouble by not charging. Like with a dead car battery, this can be fixed quite easily. Take a look.

For a standard AA battery, you should get a 5-amp, 12-volt AC/DC charger along with a set of jumper cables. Connect the cables to the charger and the black cable to the battery’s negative. Tap the battery’s positive terminal with the red cable three times. Check the battery’s voltage with a tester.

There are a few other things to keep in mind when you do this. For one, this is not the process for all batteries and even when you know the steps, you need to take safety precautions. Let’s take a look.

How to Fix Rechargeable Batteries Not Charging

There are plenty of appliances in the house that run on batteries from fun items like toys to functional ones like flashlights. When you get rechargeable batteries, you avoid having to buy extras every time your batteries die. Rechargeable batteries are also considered to be a more eco-friendly option and are also known to last longer than their non-rechargeable counterparts.

But there comes a time when these batteries can’t hold a charge any longer. Does it mean you discard them responsibly or is there a way to fix them? If you have found yourself wondering about this, you are not alone. And yes, there is a way to fix them.

The simplest way to do this is to zap them once. If you have ever tried to jump a car battery, you know what we are talking about. But if you are unfamiliar with that concept, here’s how to do it.

  • Step 1: If your battery is no longer holding a charge that means it is dead. So, first get a battery tester and make sure they are dead by checking the power level. If you don’t have a battery tester, you can do the same using any of the digital multimeters available in the market.
  • Step 2: Once you know for sure that the batteries are dead, get a 12-volt, 5-amp AC/DC charger. Check the safety warnings before you get started with the process. Once you determine that it is safe to use these batteries with the charger at hand, attach the black charger clamp to the negative terminal of the battery. The terminal will be marked with a ‘-’ sign.
  • Step 3: Now tap the positive terminal of the battery gently with the red clamp of the 12-volt charger. You might want to use protective gear while doing this because sparks might fly out of it when you tap it.
  • Step 4: After tapping it gently, place the clamps on the appropriate terminals of the battery and keep them that way for no longer than three seconds.
  • Step 5: Connect the battery with the tester or a digital multimeter and see if it has been powered back on. You should repeat this process till the battery reaches its full capacity.

If you are trying this with a NiMH battery, here’s what you need to do.

  • Step 1: Check the dead battery’s voltage with a battery tester to make sure it is completely dead.
  • Step 2: Get a new NiMH battery with the same specifications as the dead battery.
  • Step 3: Connect the positive terminal of the new battery to the positive of the dead battery and do the same with the negative terminals of both batteries with jumper cables.
  • Step 4: Hold the connection for 20 to 30 seconds and immediately check the voltage of the dead battery with the battery tester. If you get a reading that is above zero, then the battery has been revived. If not, repeat the process.
  • Step 5: Charge the battery till it reaches its full capacity.

You can also do the same without using a cable. Connect the terminals of the two batteries directly by placing them back to back and holding them together with a pair of kitchen tongs.

Why This Happens

Different batteries stop holding charge for different reasons. For instance, lithium-ion batteries are a lot more expensive than regular AA or AAA batteries. These are used in electronics like smartphones and laptops. So, if you notice that they are not working as efficiently as they used to, here is what you can do.

You will need to do what is called a full recharge which means, you must drain the battery to zero percent. Then, attach the power outlet to the battery and leave it that way for at least 48 hours. Sometimes, that is all it takes.

Now, another reason is that there is a problem with the battery bank. Devices that use more than one battery contain what is called a battery bank. If your battery is no longer holding charge, it is possible that the battery bank is badly constructed.

The circuitry might have a problem with charging and discharging. This happens when there is a voltage problem in the circuit that makes the batteries run out of power a lot sooner than they should.

Voltage problems might occur due to the manufacturer’s fault or because you made a mistake. Mixing old batteries with new ones even if they are from the same manufacturer is one such classic mistake. That’s because based on their life cycle, batteries have a different capacity. And obviously it is the same problem if you mix up batteries from different manufacturers.

You might also be using the wrong charger for your batteries which has triggered a long-term problem. There are different types of batteries in the market and they all work on specific chargers. You don’t experience this problem with Li-ion batteries because they have a fairly consistent voltage which is not the case with all chargers.

Frequently Asked Questions

How Do You Fix a Rechargeable Battery That Won't Hold a Charge?

Get a pair of jumper cables and zap them. Connect the cables to a 12-volt, 5-amp charger. Now connect the other end of the black cable to the battery’s negative terminal and tap on the positive terminal of the battery with the red cable. Do this three times for a couple of seconds at a time. Be prepared to see some sparks fly out. It is recommended that you wear insulated clothing and wear protective gear on your face so that the sparks don’t cause trouble.

Do this a few times and check the voltage reading of your dead battery using a battery tester. If you see a value above zero, you have succeeded.

Why Do My Rechargeable Batteries Die So Fast?

There are quite a few reasons why this might happen. Rechargeable batteries start losing power when they are charged but not being used. This is a process called self-discharge. That’s why you must charge them only right before using them. But if that is not the problem, remember that there is a limit on how many times a set of batteries can be recharged. So, it is possible that they are at the end of their lifespan.

Another possibility is that you have overcharged them and they are losing their ability to reach 100 percent when you recharge them. Overcharging is the process of leaving the batteries in a charger that is switched on for a lot longer than you should. Typically, it takes a charger a maximum of six hours to charge one battery. So, for a couple of AA batteries, it takes 7 to 13 hours. If you leave them in a  regular charger for longer than that, you are overcharging them.

You can avoid this by getting a charger which has a timer. Some of these stop charging the batteries after about 4.5 hours thus saving you the trouble of staying on watch. You can also get a smart charger. These come with the capacity to switch off automatically when they sense that the batteries have reached their full capacity so that you don’t have to be on your watch the whole time.

About the author, Phil Borges

Phil Borges is a battery aficionado. He's written extensively about batteries, and he loves nothing more than discussing the latest innovations in the industry. He has a deep understanding of how batteries work, and he's always on the lookout for new ways to improve their performance.