Have you used your NiMH battery for a long time? But now you’re not sure if it’s working properly or not.
That’s a pretty common concern for RC users!
So, how to check NiMH battery condition?
You can check your NiMH battery condition in two ways. The first way is by using a multimeter to check battery condition. Simply connect the terminals of the battery with the meter’s black probe wire. The other way to check battery health is by using a voltmeter. For this, connect the positive lead on your voltmeter to positive lead on your battery. Do the same with the negative terminal as well.
Do you have any other doubts? Don’t be concerned. We’ve thought of everything.
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Testing NIMH Battery Condition
An ionic chemical paste is used in rechargeable battery systems. This offers to charge functionality and a full charge. An NIMH battery is no different.
It is usually recommended that you purchase it as a non-rechargeable battery. But even if you have a rechargeable one, don’t worry,, we got you covered.
We are going to discuss two alternative methods to check your NiMH battery condition today.
So, let’s see how you can check your NIMH health-
Using a Multimeter to Test NIMH Battery
A multimeter is a super useful tool for testing the voltage. Furthermore, you can even test esc with a multimeter.
In this method, we are going to check the NIMH battery condition using a multimeter in 2 simple steps. It’s that easy!
Step 1: Setting Up the Multimeter
To start the NiMH battery test, first, charge the NiMH battery for an hour. After that, set your multimeter’s measurement dial to read the direct voltage after turning it on.
Make sure that your multimeter dial is set to measure the full voltage capacity your battery can provide.
Step 2: Checking Battery Condition
Once you’re done setting up the multimeter, it’s time to check your NIMH battery condition, and its capacity.
To test your NIMH battery capacity, connect the negative terminal of your NIMH battery to the multimeter leads. Connect the black probe to the negative terminal of the battery. For the positive terminal, it’s the red probe.
Depending on the settings, your multimeter will show either your battery voltage or its amp reading.
If you’re testing your battery capacity, a battery voltage of 1.3-1.5 means that your battery has optimal voltage. Any value higher than 1.6 means that your battery has excessive voltage. Similarly, having less than 1.2 voltage means that your battery is Trickle charging, meaning that it will charge at a considerably slower rate.
Now, for testing the NIMH condition, if the multimeter shows an amp reading of 7v or higher for a 9V battery, then the battery is fit for use. A lower value means that the battery is not in good condition and should be disposed of immediately.
To get an accurate reading of your battery condition, you need to ensure that your multimeter is in top shape and has the proper settings. Make sure you have a proper maintenance guide for your multimeter.
Recharging And Depleting
This method is quite easy and gives an estimated reading of your battery condition. For this, you need an Intelligent Battery Charger.
Let me first explain what an Intelligent Battery Charger is.
It’s an advanced battery charger that can charge and discharge your battery. While doing so, it can also give you an accurate reading of your battery voltage, the charging rate, the charge depletion rate, etc.
Quite a handy tool to have!
So here’s how to test your NIMH battery using an intelligent battery charger:
Start off by plugging the intelligent battery charger on and setting the mode to “Charge Test Mode”. Then, put the NIMH batteries in the charging slot and set the discharge limit, and let it run.
The charger will calculate how long it takes the battery to fully charge and how fast it depletes the charge. Simple stuff.
Depending on the time it takes your battery to reach full charge and assess its health degradation, you can understand the condition of your battery.
This method is also helpful to test the capacity of your batteries.
Oftentimes, many cheap brands declare to provide high-capacity batteries. While in reality, the battery can hold far less than what’s declared. With the Intelligent Battery Charger, you can get a reading of how much charge your battery can hold.
Once you check the condition, make sure you can proper steps if the battery volts aren’t ideal. You may need to change the battery if this does not work. And this time make sure to buy the best quality nimh battery for your RC car.
How To Tell If NIMH Battery Is Bad?
You can tell if an NIMH battery is bad or dead by its voltage reading. If your battery shows a voltage lower than 1.2v, it’s safe to say that your battery is in bad condition. Lower battery voltage is an indication of slower charging. Similarly, a battery holding more than 1.6v is also bad as it’s considered to have excessive voltage.
You can easily come to a conclusion about your battery voltage by using a multimeter to read the battery status. Or, you can use an intelligent battery charger to assess the charge movement of your battery to understand its condition and capacity.
The average shelf life of an unused NIMH battery is about 5 years if kept in favorable conditions. After that, the battery slowly starts to degrade with time. So it’s important to take the shelf life of the battery into consideration as well.
Battery capacity, and how you use it has a huge role to play in an NIMH battery’s lifespan. For example, a 5000 mah battery will last about 2 and a half days if you’re using 20w of power every day.
Is It Possible to Revive Dead Nimh Batteries?
Although it’s never recommended to attempt reviving a dead battery, it is indeed possible to revive a dead NIMH battery.
If a battery has been left inactive for a long period of time, it might fail to start. Similarly, not keeping the battery at recommended temperature, aka overheating the NIMH battery can damage the battery and render it dead.
In that case, you can revive the battery. But there is no guarantee that the reviving methods will always work.
Check the voltage reading of the battery using a multimeter. If the voltage reading shows less than 1.0 volt, then the battery needs to be revived. If the voltage is above 1.2 volts, simply charging the battery will do the trick.
So, here’s how to revive a dead NIMH RC battery:
To revive the dead NIMH battery, we need to provide enough shock to bring it back to life. You can attempt these fixes to revive even your Traxxas NiMH batteries.
Take an AC adaptor and hold its red cable alligator clip against the positive terminal of the battery. Hold the alligator clip of the black cable against the negative terminal of the battery. Hold the two clips against the battery terminals for 3 seconds.
Doing so will provide enough shock to the battery. It usually takes two to three shockings to revive an NIMH battery. You should expect the voltage of the NIMH battery to rise above 1.2v per cell after the shock.
We suggest resting the battery for more than 10 minutes after shocking.
If the battery isn’t revived after several attempts, it needs to be replaced.
For reviving rechargeable NIMH batteries, freezing can be an effective solution.
To revive a rechargeable NIMH battery, you need to place the battery inside the freezer for 24 hours in a plastic sealed bag. After that, let the battery warm up to normal room temperature. Charging and discharging the battery a few times will revive the batteries.
Take Care of NIMH Batteries
To keep your NIMH batteries in top shape, it’s recommended to follow a few basic battery conditioning tricks. Not only will it increase the lifespan of your batteries, it’ll also make sure that your battery runs at its best all the time!
New NiMH batteries usually require to be cycled 3-5 times to reach their peak performance. You can condition the battery by using them and recharging them back. Or, you can use an intelligent battery charger to charge and discharge your batteries.
It’s also important to keep an eye on how you charge your NiMH batteries. You should closely monitor the voltage at which your NIMH batteries are being charged.
NIMH batteries has a tendency of incurring damage from being overcharged. Modern NiMH battery cells overcomes the problem by introducing oxygen recycling catalysts. Batteries won’t concede any damage from overcharging thanks to this as long s the charge rate is below C/10.
How much voltage is required for reaching full charge depends on the temperature too.
The rule of thumb is to ensure at least 1.41v per cell at 20°C temperature.
You can charge your NIMH batteries to full charge within 3-6 hours using rapid charge depending on the rate of charging. For fast charging, your NIMH battery can be fully charged within 1 hour. The rapid charge provides a charge rate of 0.3-0.5C an hour. On the other hand, you can expect a charge rate of 1C from fast charging.
Will NIMH batteries go bad?
Answer: Standard NIMH AAs will degrade over time if they are not used. They will lose their charge and, as a result, hold less power over time.
How long do NIMH batteries last?
Answer: A NIMH battery lasts around 5-6 years. Batteries made of nickel-metal hydride (NIMH) can be recharged hundreds of times. This enables them to serve in the same capacity as hundreds of alkaline batteries.
Is it acceptable to substitute NICD for NIMH?
Answer: NIMH cannot be used in place of NICD batteries. The NIMH would quickly deteriorate as a result of this. This is because it will be charged under NICD charging conditions.
Now you know how to check nimh battery condition. You also know how you can revive your nimh battery.
However, we advise you not to use faulty batteries. Because they can explode if they’re heated. So, be safe when you’re using nimh batteries.