7 Tips To Take Better Care Of Your Rechargeable Batteries

Do you have those rechargeable batteries? Do you want to know how to get the most out of them? Then, you have come to the right place!

Note: If you are looking for information about the battery in your smartphone (lithium ion), please visit https://www.miniphysics.com/7-tips-to-longer-lasting-battery.html.

I will tell you how to prolong the useful lifespan of your rechargeable batteries, specifically nickel metal hydride (NiMH). One example of a rechargeable battery with NiMH technology is Energizer rechargeable batteries.


Some properties about NiMH batteries first:

– NiMH has high self-discharge rate and loses about 20 percent of its capacity within the first 24 hours, and 10 percent per month thereafter. (Some brands claim that their batteries can slow down this self-discharge rate)
– Low internal resistance (as compared to normal alkaline batteries). This makes them suitable for high current drain applications.


Here are some tips to take better care of your NiMH batteries:


1) Once every few months, discharge the NiMH battery fully and recharge them again.

Reason: This will prevent the battery from forming crystals in the area that has not been discharged. Crystal formation in battery = a very bad thing!

What should you do: Take your NiMH batteries out for an exercise once every few months. They need to exercise to keep fit.


2) Use them!

Reason: If you leave them alone for a long time, crystals will form in the battery. The crystals will impede the battery’s ability to retain charge.

What should you do: Refrain from leaving the batteries unattended for long periods of time. The loss of capacity due to crystal formation may be permanent.

Note: To break up the crystals in the batteries, discharge and charge the batteries a few times. (Try at your own risk. Stop charging if the batteries become unbearably hot to the touch.)


3) Refrain from using ultra fast chargers

Ultra fast chargers = those chargers that offer a 1 hour charge. Normally, ultra fast chargers only charge batteries to 70% charge level. They are unable to bring the batteries to 100% charge level as the process takes a long time.

Reason: Normal chargers apply a trickle charge after the initial charge to 100%. It is this trickle charge that ultra fast chargers lack. Hence, ultra fast chargers will damage your batteries. (Even though the manufacturers will not tell you this piece of information)

What should you do: Use a normal smart charger to charge your batteries. If you care about convenience, then just use the fast chargers.


4) Do not charge at high or low temperatures

Charging at room temperature (15 degrees Celsius to 40 degrees Celsius) is the best.


5) It is not necessary to discharge the battery fully before charging them

If you do so, you are exposing your batteries to undue stresses which will affect their performance.


6) Do not charge batteries of different charge level in the same charger

Reason: More charge will flow into the weak battery, causing the weak batteries to become hot. This may cause the battery to explode if the pressure inside the battery reaches critical levels.

What should you do: Only place NiMH batteries of approximately the same charge level into a NiMH charger. It is also advisable that you only charge the same brand of rechargeable batteries in the same charger.

Note: You can charge different brands of rechargeable batteries with a single charger. (Meaning: You can charge sanyo rechargeable batteries with energizer smart charger). BUT, you have to ensure that the rechargeable batteries and charger are of the “same type”. (NiMH batteries with NiMH charger, NiCd batteries with NiCd charger.)


7) Storage: If you have to store them, store them at a cool place with a moderate level of charge. (~40%)

Reason: Performance degrade whenever they are stored at elevated temperature.



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10 thoughts on “7 Tips To Take Better Care Of Your Rechargeable Batteries”

  1. Drill Batteries Store in United States has a large selection of cordless power tool batteries for Dewalt, Makita, Bosch, Craftsman, Milwaukee, Black & Decker, Ryobi tool and Dyson vacuum cleaner manufacturers. Our direct replacement cordless power tool batteries are made using only quality cells produced by known cordless drill battery manufactures such as Panasonic and Sanyo. These cordless power tool batteries are tested to insure maximum run time and longevity. Backed with one of the best warranties in the business, you can count on a cordless power tool battery and drill battery chargers distributed by Drill Batteries Store – Drill-batteries.com

  2. Discharging the battery completely recharging then discharging it once more before recharging is how you condition an NiMh battery which simply put it is how you break up the crystals but doing this puts a lot of stress on the battery and you lose some of the batteries life so if you were to do it every single time your battery would last months instead of years before it swells and started leaking acid

  3. A follow up question. Is it ok to leave the charger (w/ batteries inserted) plugged into an outlet while batteries are not being used? Or is it better to unplug it

    • No. 1 says, “Every few months” discharge completely. We tend to get frustrated when batteries stop working at full charge. If you recharge them at the first sign, or even before they are completely discharged, they need to be discharged completely every few months

      • Discharging every use would prevent crystals no? If this is harmful if done after every use, why is it helpful every 3 mos instead?


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