switching batteries to extend life
johngood_____
batteries in series. (i.e. both in line with each other with the + end of
one touching the - ve end of the other).
Now 'one' battery always runs down much faster than the other ( the one
nearest the bulb end). Why is that?
Also is there a way to replace the batteries to get the *maximum frugal*
life from them. For instance always putting the best or worst up at the bulb
end, when i ditch one and replace with a new one? Thanks
Evelyn C. Leeper
For what it's worth, I find that batteries that are too weak for
flashlights still have enough juice to power my Walkman for a while
(even longer if I am using the radio rather than driving a cassette).
The most frugal (and most ecological) would be to use rechargeables.
--
Evelyn C. Leeper
I believe I found the missing link between animal
and civilized man. It is us. -Konrad Lorenz
Rod Speed
> Recently i bought a 3 Watt LED torch (flashlight) and it takes two AA sized batteries in series. (i.e. both in line
> with each other with the + end of one touching the - ve end of the other).
> Now 'one' battery always runs down much faster than the other ( the one nearest the bulb end).
Not even possible if they are in series.
> Why is that?
> Also is there a way to replace the batteries to get the *maximum
> frugal* life from them. For instance always putting the best or worst
> up at the bulb end, when i ditch one and replace with a new one?
You shouldnt be replacing just one at a time, you should be replacing both at once.
Thats your problem, you're replacing them one at a time and get the illusion that the one
at the bulb end is running down quicker because thats the one that has got used the most.
Bob F
"johngood_____" <time.d...@REMOOVEvirgin.net> wrote in message
news:bNB5j.898$h35...@newsfe2-gui.ntli.net...
> Recently i bought a 3 Watt LED torch (flashlight) and it takes two AA sized
> batteries in series. (i.e. both in line with each other with the + end of one
> touching the - ve end of the other).
>
> Now 'one' battery always runs down much faster than the other ( the one
> nearest the bulb end). Why is that?
There is no reason. Both batteries have exactly the same current drawn from
them. Unless, of course, something in your light is shorting out one of the
batteries.
Bob
Al Bundy
wrote:
I have been working with batteries for decades and there is no
scientific reason for what you say to be true. Series batteries of
equal strength going in must discharge in a similar manner. The
exception that I have seen on cordless drills and possibly with your
led flashlight is that the manufacturer offers two settings on the
speed or light. With cordless drills for example, low speed may use 4
cells and high speed uses all six. In such a case, the four cells will
discharge faster than the extra booster two sells. People don't notice
the difference because all the cells are recharged at the same time
anyway.
I seriously doubt that this uneven discharge is occurring in your
case. A bit of minor research on series circuits would confirm what I
say.
Gary Heston
Batteries should be replaced in pairs (or however many the device uses) of
the same type and rating. When you replace one, you're leaving the partly
used on in the front, correct? That would be why it runs down first--it's
alreay partly down.
I'm in agreement with the other poster--if you're a heavy user of batteries,
get rechargables. Lithium-Ion work well, and will pay for themselves many
times over.
Gary
--
Gary Heston ghe...@hiwaay.net http://www.thebreastcancersite.com/
Yoko Onos' former driver tried to extort $2M from her, threating to
"release embarassing recordings...". What, he has a copy of her album?
Brian Elfert
>I'm in agreement with the other poster--if you're a heavy user of batteries,
>get rechargables. Lithium-Ion work well, and will pay for themselves many
>times over.
Is anyone making lithium-ion rechargable batteries in AA yet? Energizer
makes lithium batteries in AA, but they are specifically not rechargeable.
I've been told Lithium-Ion rechargables can't be made small enough for AA.
Anthony Matonak
...
> Is anyone making lithium-ion rechargable batteries in AA yet? Energizer
> makes lithium batteries in AA, but they are specifically not rechargeable.
>
> I've been told Lithium-Ion rechargables can't be made small enough for AA.
The issue is that Lithium batteries are 3+ Volts while AA batteries
are 1.5 Volts (more or less). You'll see rechargeable lithium batteries
that are designed to replace two AA cells (usually side by side) used
in many digital cameras but none to replace a single AA cell.
Anthony
Jeff
> Recently i bought a 3 Watt LED torch (flashlight) and it takes two AA sized
> batteries in series. (i.e. both in line with each other with the + end of
> one touching the - ve end of the other).
>
> Now 'one' battery always runs down much faster than the other ( the one
> nearest the bulb end). Why is that?
Nobody knows.
The both deliver the same amount of current.
Now, I would think 3 watts is a lot of power out of a set of AA
batteries, and would imagine the battery closer to the LED *could* be
hotter because the LED is shedding a lot of heat. A hotter battery
generally has a higher capacity than a cooler one though...
Why don't you load some NiMH rechargeables in it, I'll bet battery
life will be much longer and you'll save some money if you run that
flashlight much...
<URL: http://www.bushwalking.org.au/FAQ/FAQ_Batteries.htm />
If you go to the battery manufacturers' WWW sites (energizer.com for
instance) and look up the technical data on batteries, you will find
that alkaline batteries have vastly different energy content depending
upon the drain to which they're subjected. By 'vastly', I mean 3:1 or
more, getting worse and worse as the drain goes up. Alkalines are also
more temperature sensitive than lithium cells. Part of this has to do
with the internal impedance (resistance) of the battery, part to do with
the chemistry. That's why alkalines are absolutely worthless in
high-drain applications like digital cameras but work great in
relatively low-drain applications like LED headlamps, Walkman radios
(not CD players), etc.
Jeff
Gary Heston
Perhaps Ni-MH would be a better choice:
http://www.softwareandstuff.com/CES10220.html
looks reasonable.