| Archive for Downsizer For an ethical approach to consumption |
| lowri |
Re-chargeable Batteries - the pitfalls!I don't buy battery-powered gadgets often, but got a kitchen scales recently. I had trouble getting the LCD readout to work correctly, and by reading every word of the instructions (booklet inside box) I discovered I was NOT to use rechargeable batteries!I have a little torch/radio (I think it was a giveaway with something) and if I put rechargeables in they last about 2 days with minimum use. Do rechargeables not last so long "because you can always recharge them"? With all the BOGOF offers in stores and filling-stations, I sometimes wonder if it is worth the extra expense. My clock and smoke alarm batteries get changed once a year regardless. Anyone else had problems/got solutions? |
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| marigold |
I bought a recharger and batteries for my digital camera and was very disappointed, they took ages to charge and didn't last 5 minutes. Back to Boots for some "proper" ones on 3 for 2 offer... | ||||||
| Jamanda |
There are rechargables and rechargables. The cheap ones don't last very long between charges but the bigger ones hold their charge and seem to do well. | ||||||
| cab |
And the better ones seem to take the rigours of being used over, and over again better. But even the best ones still have a habit of suddenly dying on you, which is a pain; I carry spare non-rechargeable batteries for my cycle lights just in case. |
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| Treacodactyl |
I'm sure someone will post a more detailed explanation but I think many products aren't designed to use rechargeables. There's quit a difference between an alkaline AA battery and many of the different types of rechargeable, some of which are better than others.
One obvious difference is the voltage, my Ni-MH rechargeable AA batteries produce 1.2 volts whereas a alkaline AA produces about 1.6v, so if something uses 4 it's 4.8v vs 6.4v, so I would have thought the equipment would require 5 rechargeables. |
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| dougal |
It is very foolish to "diss" all rechargeables.
Similarly, it is "poor" behaviour for a manufacturer to suggest that such-and-such an item must not be used with rechargeables -- oh and incidentally you can buy "proper" batteries at the shop where you bought this item... 
It depends on the battery! In a previous thread, I posted a *link* to details of discharge voltage against time -- which showed that NiMH cells actually hold up better (for more of their capacity) than alkaline ("duracell") disposables. Here are the graphs see how the "1.5 volt" alkaline very soon gives less that 1.2 volts... 
while the "1.25 volt rechargeable" hold up above 1.2 volts for rather more of its capacity! 
Battery technology. Battery capacity. Charging. Safety-critical applications. Nickel Cadmium ("NiCd") technology should be avoided. These rechargeables are/were cheap. But they are pretty poor batteries, and are a disposal problem. Avoid them and I won't have to explain the 'memory effect'. Nickel Metal Hydride ("NiMH") are massively better - but being more expensive they aren't always supplied as 'original equipment'. "What was in it when it was new" isn't always the best. And the very best needn't cost much. 4 AA-size NiMH batteries are £2.99 in Aldi now. (£1.99 when in Lidl, but just 99p in Lidl's end of year clearance...) But sure, you can pay lots more for the same sort of thing. Maybe £8 on Amazon... I don't know about Harrods or Harvey Nicks, sorry. The capacity is about "how long it'll run for on one *full* charge". The measurement of battery capacity is in "Amp Hours" (or 1/1000th of them milli-amp-hours mAh). The Lidl NiMH AA's hold 2,400 mAh. I've seen NiCd with a rating (even when new) of only 300 mAh... that is just 1/8th of the capacity. Fail to look after the NiCd's and they will get worse. Avoid NiCd, remember? And 2400 is right up there alongside the capacity of "Alkaline" (duracell) disposables. http://en.wikipedia.org/wiki/AA_battery
Look for the capacity marked on the battery before buying it! You can only get out of a rechargeable what you put into it. Obviously. So to get 2,400 into a battery is going to take the exact same charger 8x as long as to put 300 into a battery ... Its worth getting a "proper charger" (costing less than £10) that can be adjusted to suit batteries of different capacities. By the way... 2400 mAh at 1.25 volts is 3 watt-hours. 1000 watt-hours is an electricity charging unit, maybe 10p-worth. So these batteries hold about 1/30 th of 1p worth of electricity -- and Duracell disposables cost about 75p each (or more) -- incidentally about the same as NiMH cells from Aldi... that can be recharged over 1000 times... For a truly safety critical application (typical example: a smoke alarm - you have all got one, surely?) if someone wanted to use a disposable I wouldn't criticise them. But I'll bet that the fire brigade and police use rechargeables in their personal radios... Don't allow poor performance, poor life, rapid self discharge in storage and poor care of old-fashioned Nickel Cadmium (NiCad, NiCd) batteries to deter you from using NiMH rechargeables. Rechargeable NIMH cells make excellent financial and environmental sense. |
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| Treacodactyl |
Those findings don't seem to match up with my batteries. I have 1300mAh Ni-MH rechargeables and when charged they never don't go much above 1.2v and don't last anywhere near as long as alkaline in a digital camera or torch. IIRC when the digital camera required new batteries the alkalines measured just under 1.2v and could be used in other equipment for a while. | ||||||
| Jamanda |
I don't see the problem with them not lasting as long in a camera as a conventional one. Just put freshly charged in ones before taking the camera out for the day - that said I've not changed mine since before the Aber meet and they are still going strong. | ||||||
| Treacodactyl |
I expect it depends on the camera, our old one only took a few pictures so we had to take spare batteries and sometimes a backup supply of alkalines as well - in the end it was much easier just to use the alkalines.
However our digital SLR has it's own special Li-ion battery and that lasts for literally 100s of photos. Next time I buy a torch I think I'll see if there's a reasonable Li-ion rechargeable one around. |
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| Jamanda |
We got a couple of those shake up torches with no battery. Thirty seconds shaking lasts for hours. And if they get turned on by accident in the bottom of your bag on in the dash board it doesn't matter at all. | ||||||
| RichardW |
Check out dougals post again. He said that 2000mAh plus was equal to a duracell. For cameras you realy need 3 sets of batts, one in the camera one in the camera bag fully charged & one set on charge. We have been using the ni-mh's for a long time starting with the 1200mAh ones when they were the best avaliable & cost over £3 EACH. We now have the 2700mAh (all AA) ones & got the cheap (about 40p each I think) from Lidl but they are lasting well. So far we have not had any fail & are still using some of the 1200 mAh ones. Some how though you do seem to loose them (kids I guess). Justme |
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| dougal |
Yes, that's right, the 1300 mAh capacity indicates that they have roughly half the capacity of alkaline disposables. Off to Aldi with your £2.99 ! 
http://forum.downsizer.net/viewtopic.php?p=471479#471479 You could have *15* packs of Aldi NiMH AA's for the cost of one spare/replacement Li-Ion pack for that thing! How much capacity (essentially how long it runs on a given load) a battery has is given by the capacity numbers. (NiMH will lose capacity as it ages, but it should be good for 'nearly' the rated capacity for a long time... 1000x charged every second day is almost 5 1/2 years...) For applications like laptops and cellphones, the game is to get the maximum capacity with minimum weight -- even if paying extra for materials, manufacturing and charge management (Li-Ion needs careful (ie 'smart', ie there is a cost element) control for safety). It all depends how much you want to pay to lose a few grammes from the product weight... |
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| Treacodactyl |
How strong is the light? I bought Bugs a wind-up 3-LED rechargeable torch a few years back. She uses it a fair bit and it's fine for walking but not good enough for cycling or working by. I've a 8 LED head torch that's great with new alkalines in and ok with rechargables and when I need to replace it would be worth getting a Li-ion powered one if possible. |
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| Barefoot Andrew |
My Canon digital compact gets through standard AA batteries like no-one's business. I had originally used Jessop's 2amp rechargeable but these were rubbish; a subsequent purchase of Panasonic rechargeables have proved much more reliable.
Meanwhile my dSLR uses lithium-ion batteries, and as TD says they seem to last for blinking ages
A. Hmm, edited because I can't spell ion 
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| cab |
The custom battery in my Sony DSLR lasts for ages, but so does my digital compact (Olympus u740, which also has an Li-ion battery).
Battery life should be a prime consideration in selection of any camera, don't be scammed by funky features, get good optics, good battery, and a camera with enough resolution and good colour balance. Alas, the days of cameras without batteries are no more (I so rarely get to use the Olympus Trip 35 these days  ). Of course, on the plus side, you don't need film any more...
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| Jamanda |
It's a small hand held torch. It gives enough light to see your way walking or reading a map in the dark. I wouldn't want to do much more work than that by it. It's totally the wrong design for cycling. |
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| Treacodactyl |
Thanks, I understand now. However, this highlights another problem with rechargeables doesn't it? My 1300mAh aren't that old and were some of the best available at the time, I have over a dozen of the AA ones. If I buy some more like the 2700mAh then the 1300 ones will never get used and might as well be thrown away, or rather recycled.
Yep, I remembered that and agree it seems very expensive. However, the prices will come down. A spare battery for my D-SLR would have been £50 a year or so ago, I can now get one for under £10. |
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| Barefoot Andrew |
a100? A. |
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| cab |
Yep. While the new a700 is lovely, its awfully expensive, and I've been delighted with the a100. |
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| RichardW |
Not at all. We still use the lower powered ones just as much as before we got the better ones. You just put them in less hungry or less used items. Keep the high power ones for cameras ect. Justme |
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| Treacodactyl |
I don't have many gadgets although I'll see how well they do in my bike lights. |
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| RichardW |
Not gadgets as such mainly kids toys, small tourches, hand held two way radios, wall clocks. Justme |
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| james_so |
Be sure to carry spares, NiMH batteries stop working quite suddenly when they discharge.. |
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| Windymiller |
I've found that the simple chargers supplied with many rechargeable battery-powered devices, are very poor, either under or over charging. I am currently looking for smart intelligent chargers for my power tools, and for the 4,500mA/hr NiMH cells I got from Lidl at £1 each. | ||||||
| Windymiller |
They also self-discharge twice as fast as NiCds do, |