Rechargeable Batteries Guide

Buyer’s Guide

Rechargeable Batteries

In this buyer’s guide, our experts will guide you through the universe of rechargeable NiMH batteries. By the end, you’ll be able to shop for and use your batteries like pro.

Advantages of rechargeable batteries


Depending on the model and brand you choose, a rechargeable battery can last between 5 and 10 years (or until you’ve ran out of cycles) and can be recharged up to 2,000 times. Now that’s what we call a good investment!


Buying rechargeable batteries has never been so affordable: not only do they last for years, but the prices are much lower than they were in the past.


Did you know that it’s easier to recycle rechargeable batteries than alkaline single-use batteries? Also, they’re often made from recycled materials.

Cycles & capacity: what you need to know

Before comparing different rechargeable batteries, it’s important to understand the difference between a battery’s capacity and the number of cycles it can do. Here’s a quick summary that will help you make an informed decision:

Battery capacity (mAh)

The length of time between each charge depends on the capacity of the battery (measured in mAh-milliamperes). The higher the capacity, the longer the battery will last between each charge.

Number of cycles

The cycles represent the number of times a battery can be discharged and recharged. So, the more cycles a battery has, the more you can use it. Batteries can have between 300 and 2,000 cycles, depending on the brand.

Capacity VS cycles

Generally speaking, the higher the capacity of the battery, the lower the number of cycles it will do. Manufacturers have therefore created different battery recipes to find the perfect balance between capacity, cycles and budget.

2000 mAh
2100 cycle
2550 mAh
500 cycle
2600 mAh
300 cycle
2600 mAh
500 cycle
2000 mAh
1500 cycle

How many cycles do I need?

Here’s an example of how to calculate the number of cycles you’ll need for your device in relation to the amount of times you recharge your battery:

1x / month
1 x 12 months x 7 years = 84 cycles
4x / month
4 x 12 months x 7 years = 336 cycles
8x / months
8 x 12 months x 7 years = 672 cycles
16x / months
16 x 12 months x 7 years = 1,344 cycles

*7 years: average lifespan of a battery.

Rechargeable batteries can last between 5 and 10 years depending on the brand.

If you don’t need many cycles, we suggest you opt for a battery with more capacity or a low self-discharge rate. You’ll find more info on this below.

Different uses

Comparison table

Best practices

Recharge your batteries before using them

If you power your device with a 2,000 mAh battery that’s discharged down to 50% of its capacity (1000 mAh) and a second battery that’s fully charged (2000 mAh), your device won’t make the most of the 2000 mAh available. It will be limited by the weakest battery. Charge both batteries fully to get the most out of them.

Same brand, same model

Different brands often use different types of technology.

We therefore suggest that you group batteries from the same brand and model together to ensure they perform at their very best.

Similar capacities

For maximal power, combine batteries that have the same power (mAh) together.

If you use an Eneloop 2000 mAh battery and an Eneloop 2550 mAh at the same time, the Eneloop Pro will be less powerful than expected.

The old with the old and the new with the new

As batteries get older, their capacity decreases. To get the most out of your batteries, use a combination or either old batteries or new batteries. Avoid combining both types together.

You can trust us

You can find a wide variety of rechargeable batteries on the market, all with different price tags. Unfortunately though, certain manufacturers oversell the performance of their products by claiming that they have more capacity or cycles than they really do.

At Batteries Expert, we work closely with our suppliers to ensure that our products do what they say on the tin.

For example: you purchase a battery that offers 2400 mAh of capacity, only to find that it really has 1900 mAh, or that it loses its capacity after 1 year.

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