Re: Cheap AAs worth it?

Yes, in the old days some battery operated equipment used to suffer from
distortion if operated at a lower voltage, but modern amps do not suffer
this way, just maybe a bit less volume before clipping, if you are not
already deaf by then. The more modern problem is the audio low bat warning
I've found on some bits of kit, which being the cynic that I am I think have
been set so you cannot use the rechargeable.
Brian

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"Roy Lewallen" <w7el@xxxxxxxxx> wrote in message
news:CqWdnUy4wYUM__PUnZ2dnUVZ_uGdnZ2d@xxxxxxxxxxxxxxxxxxxxxxxxxx
Brian Gaff wrote:
Yes, and what about rechargeable alkaline which seem to be being sold at
least here in the UK. I don't rate them myself as I have a sneaking
suspicion that all they actually are are ordinary alkaline with better
seals to withstand longer lives and a bit of charging. After all you can
only top them up, you cannot flatten them and expect them to recharge, in
fact exactly like the experiments I did back in the 60s with ordinary dry
cells, using pulsed charging at low currents.
Brian

I looked into rechargeable alkalines some time ago for use in a GPS
receiver which drew around 200 mA as I recall. Here's what I found:

1. The initial capacity of the cells wasn't as good as primary alkaline
cells, and the difference was greater yet at higher currents.
2. The capacity of the cells decreased significantly after only a few
recharge cycles. And at higher current drains, it decreased even more.

The only real advantage I could see over NiMH or, at the time, NiCd cells
was the relatively low self-discharge. With the current availability of
good quality low self discharge NiMH cells like the Sanyo Eneloop, that
single advantage disappears. For those applications where I might not want
to use NiMH, I can get good quality AA alkaline cells from Costco for
about 25 cents apiece. I don't see a single application where the
rechargeable alkalines are a good solution, let alone the best one.

Anybody who thinks alkalines have an advantage over NiMH because of higher
voltage might like to take a look at
http://eznec.com/Amateur/1.5_vs_1.2_Volt_Batteries.pdf. Rechargeable
alkalines will perform even more poorly than the primary alkaline used as
an example, and much more poorly after a few discharge/charge cycles.

Roy Lewallen


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Relevant Pages

  • Re: Cheap AAs worth it?
    ... one could put normal Alkaline on charge after short ... rechargeable alkaline seem particularly grotty in comparison. ... The capacity of the cells decreased significantly after only a few ... recharge cycles. ...
    (sci.chem.electrochem.battery)
  • Re: better batteries
    ... >> mavica works better with alkaline batteries than the regualr heavy duty ... > In high drain rate devices such as digital cameras though, a set of NiMH ... > the alkaline cells. ...
    (sci.electronics.basics)
  • Re: Alkalines versus NiMH
    ... NiMH cells have relatively low voltage as do ... voltage available that 8 alkaline batteries give you. ...
    (rec.radio.cb)
  • Re: NiMH new battery conditioning
    ... because I had no idea what the alkaline cells' rated capacity was. ... It varies radically with load. ... Note the variations by brand and type and the NiMH cell in the bottom ...
    (sci.electronics.repair)
  • Re: Cheap AAs worth it?
    ... The capacity of the cells decreased significantly after only a few recharge cycles. ... Though the alkaline cells start by giving more output, ... transmission than the NiMH. ...
    (sci.chem.electrochem.battery)