A question about aa batteries.

If you're making a portable you probably need something to watch it on. (Unless you want to guess what's happening in the game, but I wouldn't advise that) Anyway, this forum is your "Hacking a pocket TV/screen" one-stop solution. Share your experiences and knowledge here.

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ransoman
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A question about aa batteries.

Post by ransoman »

Don't know if this is the right place to post, We really should have a battery board.

Anyway, does anyone know how many MAH a standard AA battery supplies? i know the game gear lasts 3 hours @ 850(or something)mah so i am guessing that it is arround 2600 mah. Does anyone know for sure?

finally, at approx 400mah from a modified casio + a radica, does that mean a portable of that type will last about 6 hours on 4aa's?
dankicksass
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Re: A question about aa batteries.

Post by dankicksass »

ransoman wrote:finally, at approx 400mah from a modified casio + a radica, does that mean a portable of that type will last about 6 hours on 4aa's?
The Exodus played for about six hours on four AA's, so that doesn't sound unreasonable if a Casio pocket TV's power draw is similar to a Hip Gear.
anotherperson wrote:Subconsciously, I expect the lighter ones to only last for a short time while heavier ones a lot longer.
You know, I always thought the same thing - a heavier dry cell lasts longer.
I don't like forum signatures.
timmeh87
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Post by timmeh87 »

there are two kinds of popular pimary dry-cells, standard "alkaline" batteries, and "heavy-duty" battereies, which are a completely different chemistry (zinc-carbon). heavy duty batteries are a lot lighter, and they have much, much less capacity. calling them 'heavy duty' is some sort of cheap marketing gimmic, that i persoanlly think is pretty stupid, because a lot of people actually think they <b>are</b> heavy duty.
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ransoman
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Post by ransoman »

I tried a set of zinc carbons for my gbp a long time back. I saw the "heavy duty" sign and thought, wow that's cheap!

Anyone care to guess how long it took for the gbpocket to drain them to nothing? i'll give you a hint, 40 minutes. Just a fraction over half an hour. Never again, i don't think they are usefull for anything.

Thanks for the replies.

Now next question, how to i convert watts to milliamps?
My gamegear consumes 3watts
my nomad consumes 3.5 watts
the casio consumes 3.7 watts, i want to find out what it means in mah.

Thanks.
timmeh87
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Post by timmeh87 »

ok. watts to amps. first lets review our units.

amps (A) - how many electrons
volts (V) - energy per electron
watts (W) - energy delivered

the physics equation relating these three variables is

P = VI

the watts are 'P' (power), and the amps are just 'I' for some reason. 'V' is volts.

right. so that equation agrees with common sense. <b>The amount of energy delivered to a component is the number of electrons multiplied by the energy per electron.</b>

----

example:
A 60W lightbulb runs on 120V. What current flows through the lightbulb?

answer:

60 = 120I
60/120 = I

so I, our current, is .5A.

----


For each system, to get the current it draws, you divide the wattage by the voltage. This will give you the current in amps (1mA = .001A).

Now, it should be noted that the actual wattage of the system varies. The power rating is some sort of average, or even possibly the maximum, im not sure. But its actually easier to use a multimeter to just directly measure the amperage instead of trying to calculate it.

now, the current draw of anything is measured in A (or mA or uA or GA). "mAh" is compltely different. It is ONLY used to discuss the capacity of batteries. 1 Ah means that a battery can supply you with 1A for one hour. (it dosent mean it will only supply 1A, or that 1A is the maximum current. it just means that if you try to take 1A from it, it will last an hour).

so heres the equation:

Capacity = Average Current * Total Running Time

where Capacity is measued in Ah (or mAh or uAh or GAh). once you figure out what current your things draw, then you can use this equation in the form

Capacity
------------- = Total Running Time
A. Current





========
ok so i went a little overboard, but i was writing it so i could post it on the wiki
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vskid
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Post by vskid »

I think "heavy duty" means the opposite, alkaline or rechargable is better.
Just a fun fact, my 48 in. HDTV consumes 240w, so 2 amps! :D
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Post by Skyone »

timmeh87 wrote:and the amps are just 'I' for some reason.
I for current from the German word Intensität, which means intensity. Just sayin'. :P
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Post by timmeh87 »

never knew that. cool.
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StuntMonkey
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Post by StuntMonkey »

Why is there a pink bunny on that duracell package?
Oh, & rechargables are always better. 2800mah aren't too hard to find.
Skyone
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Post by Skyone »

StuntMonkey wrote:Why is there a pink bunny on that duracell package?
Oh, & rechargables are always better. 2800mah aren't too hard to find.
Well, the whole catch of the duracell bunny is that it is powered by a Duracell battery and can keep using energy for a long[er] amount of time before the battery runs out of energy.

Also, the max rechargable AA's I've seen are 2600mAh batteries.

EDIT: I take that back!
geekbait111
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Post by geekbait111 »

skyone wrote:
EDIT: I take that back!
better re-think that again :P
meow!!!


edit: and look at this :shock: :shock: :shock: :shock: :shock: :shock:
MEOWWWW!!!
perfect for a GCp, super cheap, 12V, do they have a discharge rate?

if only they were rechargable :(
Kurt_
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Post by Kurt_ »

Something tells me those aren't AA sized...
I bet those are the long D sized ones.
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Turbo Tax 1.0
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Post by Turbo Tax 1.0 »

something tells me those batteries are wack :P
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Skyone
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Post by Skyone »

Something tells me those batteries aren't 23Ah.
Specifications:

Size: 23A

Chemistry: Alkaline

Voltage: 12V

Brand: Konnoc

Included Qty: 1
:|
geekbait111
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Post by geekbait111 »

if someone orders em and finds out they aren't 23A, SUE! ( :D :lol: :lol: :D )

Oh yeah... they probably aren't AA size more like yah... 2 D cells :cry: , still not a bad deal (considering they are 23A)
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