AA rechargeable batteries: advice

[John L]

Hi all

Like just about everyone now, I have numerous devices that use AA batteries: TV remotes; a camera; computer keyboard and mouse (what a mistake *that* was!)[1]; even a nose-hair clipper...

I've always used rechargeables. Over the years I've acquired various types as the technology has developed -- started out with 1800mAh NiCads, and the latest are 2700mAh NiMh.

I've always believed that the bigger the ma number, the "better" the battery: is this true? I'm half-expecting people to reply "No - for your remotes you want "X" type whilst for the nose-hair trimmer you want a "Y" type".

The prices seem to have gone up steeply since last I bought some -- for example at present Screwfix are selling 4x2700 for £12.71 --

advice? (Preferably brief and simple: my usage of terms like mAh above is based *purely* upon reading battery labels!)

Cheers John

[1] This is an Apple wireless keyboard (3 batteries (3, not 4 nor 2, which would have been so much simpler!) and mouse (2 batteries). They need replacing every few weeks; USB would have been infinitely better.

[OG]

The hybrid types may have lower mAh ratings, but as they have significantly less self discharge they will be a better option for equipment where you don't want to be changing the batteries every couple of weeks.

Other than that, higher mAh should give a longer life for most use - torches, radios and the like. The one exception may be digital cameras. These tend to register 'low battery' when the voltage drops below a certain level, so normal cells can cut out long before the cell has used all its stored charge.

I have a set of 7dayshop branded 2800 mAh cells that only give about 60% as many shots on my camera as a set of 2200 mAh Hybrios. This is in holidays and periods of intensive use when I expect to be recharging every couple of days or so.

[Dave Liquorice]

Bloomin heck. 4 x 2500mAHr NiMH from Lidl =A32.58 (when they have them, they go fast...)

Low power stuff like remotes, clocks etc your are probably better off using alkaline batteries as the self discharge from NICd and NiMH rechargeables is so high. The newer hybrid batteries are supposed to have a very low self discharge they would be better.

High power stuff cameras, GPS, torches etc then the larger the mAHr number the longer the runtime, in a given appliance, will be.

[Lobster]

I've bought what sounds similar from Aldi in the past (branded "FiF" and they've been completely and utterly useless (ie, losing their capacity within a few months of light use) compared with others I've owned, lie Uniross.

David

[Bruce]

Lithium batteries seem to last several years in remotes. I haven't tried them in clocks.

[Tim Streater]

Er, Dave, hybrid in what sense, please? And, how does one recognise such at the store? My wife uses 4 in her camera and they are always flat unless she charged them yesterday.

[Dave Liquorice]

The Lidl ones are "Tronic" branded, which I think is their own electronics brand. The ones I have are fine, irregular use in a camera, in fact they are the best set we have now. Self discharge has done for a set of 10 year old GP industrials and some others maybe 5 years old (that weren't that good to begin with).

[pete]

I treat the mAH rating of batteries (esp. the cheaper or unknown branded ones) like MPG figures for cars: more as a number used for marketing purposes, rather than as any sort of practical measure of their usefulness. One reason is that (cheap) cells have a self-discharge that limits their usefulness in low power devices (e.g. never use them in smoke alarms). Another is that even if they weren't completely fictitious, they probably only refer to one particular usage curve in ideal, laboratory conditions, which I doubt any of my kit adheres to.

[Harry Bloomfield]

John L wrote on 29/12/2009 :

The larger the mAH, the longer they can run an item for, but they should not be used for things which draw a relatively tiny current or are not charged then consumed almost immediately. Basically they self discharge, so running low current things like remotes is rather pointless.

If you charge batteries for your camera, use them straight away and use until flat - that would be a sensible use. I used to have a wireless mouse which came with rechargeables, that was designed to plug into the USB when not needed. My current wireless mouse runs on throw away cells

- they only need swapping every year or so and it really would not be worth the messing about with rechargeables.

It is very much 'horses for courses'.

[Mark]

LOL

Sanyo eneloop, i use them in my camera, they have only needed a recharge once a year.   

[Dave Liquorice]

The easy way is that they are the only rechargeable battery that doesn't need to be charged before first use.

A quick google shows Uniross Hydrio, Sanyo Eneloop and Rayovac Hybrid.

[Tim Streater]

[John Weston]

They have a very low self-discharge rate, so have a long shelf life and so are OK for intermittent use devices.

Google for Sanyo Eneloop. I use them in my camera flash which doesn't get used for months at a time, but they keep their charge for a good year or more. Worth getting a good, programmable charger for them, to maximise the number of recharges.

I see 7-day-shop have some AAs:

are Uniross Hybrio.

[brass monkey]

I used to have a camera where the display would show 'low bat' after only a few shots. Rotate the batteries (clean the contacts) and they would go much longer. This could occur 2 or 3 times before needing a charge. Dunno whether the buzzword 'contact rectification' had anything to do with it.

[The Natural Philosopher]

given up totally on nickel technology. Its all crap. low power runs longer on primaries, and anything else had better be LIPO or I dont buy it.

[Rod]

Anyone tried their 'own brand' ones?

Price is appealingly lower - but are they any good?

[Richard Russell]

Also GP ReCyko+ (e.g. CPC order code BT04285).

Richard.

[Richard Russell]

There's a comparison between the Eneloop and the Recyko here:

as has been noted elsewhere, comparisons of the 'out of the box' capacity are pretty meaningless because the manufacturers may not initially charge them fully.

Richard.

reply by email change 'news' to my forename.

[Dave Liquorice]

Not seen any LiPo AA cells or a suitable charger that doesn't need an arm and leg to purchase.

My experience if Li technology batteries isn't good, the one in my Minolta camera is nearly always flat or virtually so when ever I want to use it. The one in my HP iPAQ has a habit of lying about it's state of charge, both Li Ion according to the packaging but as they are both thin things they could be Li Po. The only one that hasn't given any trouble is the labled Li Po in my phone.

[robert]

In message , John Weston writes

I support this entirely. I have been using Eneloop and a MAHA MH C401FS charger for a couple of years with excellent results.