Flumpf. Posted May 9, 2008 Posted May 9, 2008 Hi all, No forum really fits this one, so as I had to spend ages unjamming three AA rechargeable Energizer batteries from my Rock Band guitar tonight, I thought I'd pose this question here. These rechargeable batteries are just a little bigger than normal AAs - so they jam in things, or covers won't close. Is there a sensible reason for this, or have I just bought a pile of crap again? Cheers! amyf.
Mr.Bitey Posted May 9, 2008 Posted May 9, 2008 Ive never noticed them to be any bigger than normal AA ones - ive got stacks of the energiser ones (and some other brands).. Infact ive just grabbed two and measured against a 'panasonic alkaline aa' - its the same... both in length and girth Cheers, BiteAA
Flumpf. Posted May 9, 2008 Author Posted May 9, 2008 Well Mr Bitey, yours are different to mine. Cheers! amyf.
penguin Posted May 9, 2008 Posted May 9, 2008 i have the same problem with my rechargables and my 360 controllers.... i pretty much have to bang the battery case on a table to get the energizer ones out of that. No problem with my guitar hero guitar tho! (Maybe the rockband guitar has a smaller battery compartment)
MACCA350 Posted May 10, 2008 Posted May 10, 2008 I've also found that my Energizer AA and AAA rechargeable's are 1.2V whereas the non rechargeable's are 1.5V Only caused an issue with one of my remotes so far, not enough juice to do it's job with 1.2V, stuck in 1.5V and worked fine cheers
DrP Posted May 10, 2008 Posted May 10, 2008 That's the correct voltage for certain types of rechargables.. nothing mysterious is going on. As for different casing size, I can't say I've noticed it, but I only use Sanyos.
MACCA350 Posted May 10, 2008 Posted May 10, 2008 That's the correct voltage for certain types of rechargables.. nothing mysterious is going on. As for different casing size, I can't say I've noticed it, but I only use Sanyos.I just thought it was strange because I have AAA batteries that wont work in a device that takes AAA batteries It wasn't until I noticed the different voltages that I found the culprit, I would have thought that the voltage would be part of the "standard" that batteries need to adhere to for compliance, but obviously not.........just seems a bit silly to me. cheers
DrP Posted May 10, 2008 Posted May 10, 2008 Most devices are happy with the 1.2 volts from recharges since single use cells can run down to 1 volt. Some stuff is picky and only works above 1.4 volts, but with that stuff you get fairly short single use cell life since the device cuts out well before the cell is fully drained.
diesel Posted May 10, 2008 Posted May 10, 2008 I generally use DSE brand AAs and have not had any issues with any kid's toys or my Harmony 525 remote. I don't see any difference in size either.
HPSOV Posted May 11, 2008 Posted May 11, 2008 Many rechargeable batteries are larger than regular 'dry' cells. I believe this is the result of companies trying to make ever increasing capacities (I remember when a rechargeable AA was 500mah, they're up to and over 2500mah these days), the easiest way to get that little bit of extra capacity is to simply cram more inside the case, or make the case that little bit bigger! As for the voltage, a dry cell is a nominal 1.5v, you'll find that they're slightly higher than this when new. However a dry cell has a very linear discharge curve, from 1.5v down to around 1.0v when its 'flat', the average voltage throughout its life may well be around 1.3v. A rechargeable battery is a nominal 1.2v, however when full you'll find they're a lot more like 1.4v, and have a very flat discharge curve, that is they maintain voltage well until they get very close to flat, when it drops off rapidly. The end result is the average voltage of a rechargeable may be around 1.2v, only slightly below that of a dry cell, and not enough to affect most devices.
dax Posted May 11, 2008 Posted May 11, 2008 It wasn't until I noticed the different voltages that I found the culprit, I would have thought that the voltage would be part of the "standard" that batteries need to adhere to for compliance, but obviously not.........just seems a bit silly to me. The voltage is set by the chemicals used. Have a look at different batteries and their nominal voltage will be from1.2 to 1.5 depending on the type. It just that most of the rechargables are a bit lower voltage while the old carbon batteries are about the highest voltage (but have less energy in them - hence the move to alkaline and now even newer methods like lithium) Most things dont care - but some devices are fussier than others. Also be careful when you have something that takes say 4 or more batteries as the difference between 4x1.5 and 4x1.2 is now over a volt.
charlesc Posted May 11, 2008 Posted May 11, 2008 I think some people also want to put rechargeable batteries into just about anything, which may not always be the best solution. Rechargeable batteries are good for things that take a fair bit of current, and run the batteries down quite quickly. Examples could be kids toys with motors, electrical toothbrushes, torches. Portable radios, boom boxes, etc. Devices that take fairly low current (their batteries would typically be changed in the 6-12 month time cycle) are probably not good candidates for rechargeables. Examples might be basic remote controls, wireless door bells, wireless alarm sensors etc. In particular, because of the lower cell voltages of rechargeable batteries compared to typical rechargeable ones (discussed in posts above), some devices would end up with lower voltages than they would be getting from standard disposable batteries. And if they take little current, this disadvantage IMO would outweigh any benefit of using rechargeable ones to save cost. I think common sense needs to prevail when choosing batteries. An understanding of the differences in battery technology and what you get in terms of device performance are important factors.
DrP Posted May 12, 2008 Posted May 12, 2008 Don't forget that the self-discharge rate of nicads and nimh cells is quite high. In light use situations you are likely to get less 'life' out of a charge of a rechargable than a use once cell.
larry42 Posted June 17, 2008 Posted June 17, 2008 (edited) I have used eneloop rechargable AA and AAA batts for a long time at home, they are great for remotes and toys....and i hate the damage that leaking batteries can cause..so no more alkalines for me..... I haven't had any problems with them fitting in devices. They are rechargable low discharge batteries, so they don't go flat like normal rechargable batts, so they are perfect for remotes... The eneloop are very good quality low discharge NiMH batteries, however the MAHA imedion batteries are even slightly better capacity (and they look great with black and silver , if that matters to you ). The eneloops on this site are a LOT cheaper than here in australia, and they work great, they come fully charged, and they don't self discharge like normal NiMH batts. There is a lot of info on the servaas site and whirlpool forum on the eneloop and imedion batts. You can order them from servaas or overseas quite a bit cheaper than local shops like DSE. Edited June 17, 2008 by larry
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