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How do you make rechargeable batteries last longer?

Bird's eye view of lots of batteries

Store them in your fridge or freezer. Don’t let them run down to empty. Whatever you do, don’t overcharge them. These are just some of the tips I’ve heard to make my rechargeable batteries last longer.

It’s no wonder we look for ways to eke as much life out of them as we can – given how expensive rechargeables can be. A pack of four AAs can cost between £6 and £13  – and a charger brings the bill closer to £30.

What do you do to try to make your batteries last longer?

Problems with rechargeable batteries

Manufacturers now claim that you’ll get hundreds of recharges from their batteries. The longest claim I’ve come across is the five-year lifetime guarantee or three hundred recharges (whichever comes sooner) for Duracell’s Recharge Ultra batteries.

But even with so many potential repeat uses, more than four in 10 of the Which? members we asked had problems with theirs in the past year alone.

Older batteries lasting less time between charges than newer ones, difficulties in charging them and batteries not lasting as long as expected on one use were among the most common problems.

So if you’re looking to buy new batteries. what should you look for? Our tests have found that the best rechargeables strike a balance between long battery life on a single charge and reasonably fast recharging. Plus, they don’t leak away charge when not in use.

Oh and that tip about sticking the batteries in the fridge? Our sister publication in the US, Consumer Reports, has tried this with disposables but sadly found it made minimal difference to battery life.

Can you recycle rechargeable batteries?

When they do reach the end of their useful life, rechargeables should be recycled, like disposables, at battery recycling points. You can usually find one at supermarkets or anywhere that sells a range of batteries.

A true reusable would be made from recycled material. Energizer’s EcoAdvanced range claims it’s the first disposable battery partly made from recycled batteries. It’s just 4% recycled at the moment, but the company aims to make this 40% in a decade.

What do you do to get the most from your rechargeable batteries? Have you tried any of the tips we mentioned earlier?

What problems have you had with rechargeable batteries?

Batteries not lasting as long as expected between charges (31%, 249 Votes)

Older batteries not lasting as long between charges (30%, 246 Votes)

Failing to charge altogether (12%, 94 Votes)

I have had no problem with them (8%, 62 Votes)

Difficulty charging (7%, 56 Votes)

Leakage (7%, 53 Votes)

Batteries not fitting the charger or device properly (5%, 43 Votes)

Other problems (please state in comments section below) (1%, 8 Votes)

Total Voters: 431

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Comments
Member

My pet hate is the AA and AAA batteries that are physically bigger in diameter than “normal” batteries and simply don’t fit torches, remotes, carbon monoxide detectors, etc. They all seem to fit chargers which tend to have springloaded contacts and spacious slots. The Lidl and Aldi brands are like that. They work really well IF you can get the battery into the device.

Member

For years I used rechargeable AA and AAA cells regularly but many products (e.g. cameras) come with batteries or the drain is so low (LED torches, clocks, remote controls) that it isn’t worth using rechargeables. From limited experience of modern rechargeables, they do seem to be much better at holding their charge when not in use.

Lithium rechargeable batteries (standard in phones and laptops) can be discharged fully without harm. Other rechargeables including the types shown in the photo and battery packs for power tools should NOT be fully discharged, and you should stop using them as soon as they appear to be running out of power. What happens is that when one cell in a battery is exhausted it is reverse-charged by the others, causing further deterioration.

Some chargers are better than others. If batteries become hot when on charge they will gradually dry out and become useless.

Member

Thanks for your comment wavechange. You can indeed use devices such as phones and laptops containing lithium rechargeable batteries until they stop working and then recharge them without damaging the batteries.

With NiMH (nickel metal hydride) batteries – such as most AA and AAA rechargeables but also found in some devices such as handheld vacuums and power tools – you should recharge them as soon as you notice the performance of the device is dropping off. This will help preserve the cells in the long run.

Member
Gerard Phelan says:
29 July 2015

I have an ‘intelligent’ charger which has problems with some Maplin NiMh rechargeable batteries of C or D sizes. Even when they were just a few months old, the charger would report them as ‘bad’. A multimeter showed was probably the result of them discharging to to zero volts. So I have to start them off in an older unintelligent charger after which the ‘intelligent’ one is happy to complete the charging. ( The ‘intelligence’ is in stopping the charging when it is complete. )

Another problem I have is with older NiCad cells which I have in groups of 4 or 6 in some equipment. Now many years old, one of the set has completely failed leaving me with an incomplete set of 3 or 5 cells that are otherwise still usable. NiCad cells longer seem to be available and we are warned not to mix NiCad and say NiMh cells. It seems a waste to have to throw good cells away and C and D sized cells are expensive, whatever the technology.

Member

Thanks for your comment Gerard. I’d be interested to know the types of devices you’re using your C and D size rechargeable batteries in which seem to discharge them completely.

You’re correct that NiCad batteries are no longer available. Nickel Cadmium cells (those containing more than 0.002% of cadmium by weight) can’t be sold in the UK for consumer use, following EU legislation in 2006. Although there are a couple of exceptions – including those sold in cordless power tools (until Jan 2017) and batteries intended only for medical equipment.

Member

Gerard – I have also seen rechargeable batteries that refused to charge on a modern charger. You may well be right about the reason. I have disposed of all my old rechargeables recently – they were all over ten years old. They have served me well but new ones seem so much better.

Mixing rechargeable batteries is not a good idea because this increases the likelihood that one will discharge before others and be reverse-charged, as I have described above.

The only benefit of NiCD batteries over NiMH is that they hold their charge longer when not in use. Newer NiMH seem much better in this respect.

Member

Sarah – What Gerard says is quite correct. The capacity of individual batteries in an apparently identical set will differ and this difference becomes greater with age. As the batteries are discharged, one or more can become exhausted while others are still partially charged.

Member
Gerard Phelan says:
29 July 2015

The completely discharged cells are in a Grundig Concert Boy radio, that requires six type D batteries and a Yamaha electronic keyboard that requires six type C batteries. I do not use either very much, but that was why I decided to put in rechargeable batteries. There was formerly a Sony Radio Cassette player used daily that required 6 C rechargeable cells, but when the cassette part died, so did my use.
I think they expire through self discharge more than through usage. These issues have put me off extending my use of rechargeable batteries. Out of over 140 items using 254 batteries I have 6 items using 28 rechargeable standard cells, although built-in and special batteries takes my rechargeable item count to 23.