What Do You Look For In Rechargable Batteries?


Go for the highest Mha, all rechargable AA's are 1.2v as far as i'm aware.

i have energiser 2300Mha and i get 3-5 hours dependant on the emu.

Hope this helps :)
 
I think for NiMH rechargeables the voltage are pretty much the same across the board. You definitely need 2500mAh at least, though. I got a pack of these and they work great. There are better brands out there, but you'll have to dig for them and they'll probably cost more. You can probably find these at a local electronics store.
 
Those should do fine.

Also, if you're referring to mail-ordering as being "close to the store", I've found it's usually just as cheap to buy in-store for most things (not SD cards though <_< ) once you factor in shipping.
 
Ravnos posted on Feb 4 2006 at 11:20 AM said:
Those should do fine.

Also, if you're referring to mail-ordering as being "close to the store", I've found it's usually just as cheap to buy in-store for most things (not SD cards though <_< ) once you factor in shipping.

Well, I mean literally I could walk into that store and buy it for the price that I see right here:

http://www.tigerdirect.com/applications/Se...1168668&CatId=0

But, I just found out something nice using the search feature...

Squidge posted on Dec 31 2005 at 01:20 PM said:
hmmm, lets do some idle tests in an attempt to find the optimal voltage :)

@ 2.5V = 410mA.
@ 2.9V = 340mA.
@ 3.3V = 300mA.
@ 3.4V = 290mA.
@ 3.6V = 280mA.
@ 3.7V = 270mA.
@ 3.8V = 260mA.
@ 4.0V = 260mA.

I think a battery capable of providing 3.7V is the winning one here. Who would have thought by just increasing the voltage by 1.3V, you would drop the consumption by 150mA ?

So, judging from these tests, for rechargable batteries, 3xAA (giving 3.6V) would give a LOT more playtime than 2xAA, simply due to the fact that the 2X doesn't have to waste as much energy to increase the voltage to it's preferred range.

Lets try this on mplayer:

2.5V - upto 850mA
2.9V - upto 690mA
3.1V - upto 650mA
3.3V - upto 590mA
3.7V - upto 530mA (270mA in stop mode)

Hmmm, a saving of over 300mA by just increasing the battery voltage. Nice :)

Now onto the search for finding higher voltage batteries xd
 
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a lot of the cheaper nimh cells will come unconditioned and will require a half dozen full cycles before they get to their full potential. Don't be discouraged if your fancy new cells only last 5-10 minutes for the first few charges.

as always, rechargable alkalines and nicads are completly out of the question. also be careful with higher voltage batteries, a lithium cell at 3.6-3.7 is probably fine, but I wouldn't go above 4V--gp2xes are forgiving, but not that forgiving.
 
I doubt they are really 1.5V since they are still NiMH chemistry, but I could be wrong.
My understanding is that all NiMH batteries start at about 1.4V at full charge, rapidly drop to 1.2V and stay there until they are nearly depleted, when the voltage drops off. It's only the capacity which differs between different NiMH batteries.

If they *were* truly 1.5V they would be better, since they have a greater capacity (1.5V * 2.5 Ah = 3.75 Wh [Watt hours] versus 1.2V * 2.5 = 3 Wh), in addition the GP2X seems to use power more efficiently at that voltage as explained in the post you quoted.

That said these sound like they would be as good as any other batteries, at least!
 
Ravnos posted on Feb 4 2006 at 05:06 PM said:
I think for NiMH rechargeables the voltage are pretty much the same across the board. You definitely need 2500mAh at least, though. I got a pack of these and they work great. There are better brands out there, but you'll have to dig for them and they'll probably cost more. You can probably find these at a local electronics store.

What do you mean you need 2500mAh at least!? How much do you guys play? I bought a recharger with four 2300 mAh batteries, and I don't think I've ever managed to use all that batterypower. Two sets 2300 mAh is at least 6 hours playtime a day, and that is more then sufficient. (for me anyway)
 
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Fiendicus_Prime posted on Feb 4 2006 at 11:44 AM said:
I doubt they are really 1.5V since they are still NiMH chemistry, but I could be wrong.
My understanding is that all NiMH batteries start at about 1.4V at full charge, rapidly drop to 1.2V and stay there until they are nearly depleted, when the voltage drops off. It's only the capacity which differs between different NiMH batteries.

If they *were* truly 1.5V they would be better, since they have a greater capacity (1.5V * 2.5 Ah = 3.75 Wh [Watt hours] versus 1.2V * 2.5 = 3 Wh), in addition the GP2X seems to use power more efficiently at that voltage as explained in the post you quoted.

That said these sound like they would be as good as any other batteries, at least!

How can I test this myself? I think I will go today and buy them, test them out, and see if they really are 1.5V (and of course how well they work in the GP2X)

EDIT: Damn asshats..

http://www.tigerdirect.com/applications/Se...p?EdpNo=1168668

Click on the picture: it says 1.2V ON THE BATTERY, yet it says 1.5V in the description...

Time to find out how to hook up 3 batteries into it xd
 
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If you hook up 4.5v to a device designed to take 3-3.3v you WILL fry it slowly. It's basic electronics. You can get batteries that have as many amps as you can, but don't raise the voltage, or eventually it won't work at all with batteries.

-Kensupen

P.S. I took a 2 year cert in electronics, so I'm not just blowing wind in my sails.
 
Silberstein posted on Feb 4 2006 at 09:50 AM said:
Ravnos posted on Feb 4 2006 at 05:06 PM said:
I think for NiMH rechargeables the voltage are pretty much the same across the board. You definitely need 2500mAh at least, though. I got a pack of these and they work great. There are better brands out there, but you'll have to dig for them and they'll probably cost more. You can probably find these at a local electronics store.

What do you mean you need 2500mAh at least!? How much do you guys play? I bought a recharger with four 2300 mAh batteries, and I don't think I've ever managed to use all that batterypower. Two sets 2300 mAh is at least 6 hours playtime a day, and that is more then sufficient. (for me anyway)
I don't know how anyone can get 6h out of 2300mAh. My 2 sets of 2500's get me through a 9h work day with not much to spare afterwards.
 
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Ravnos posted on Feb 4 2006 at 07:38 PM said:
Silberstein posted on Feb 4 2006 at 09:50 AM said:
Ravnos posted on Feb 4 2006 at 05:06 PM said:
I think for NiMH rechargeables the voltage are pretty much the same across the board. You definitely need 2500mAh at least, though. I got a pack of these and they work great. There are better brands out there, but you'll have to dig for them and they'll probably cost more. You can probably find these at a local electronics store.

What do you mean you need 2500mAh at least!? How much do you guys play? I bought a recharger with four 2300 mAh batteries, and I don't think I've ever managed to use all that batterypower. Two sets 2300 mAh is at least 6 hours playtime a day, and that is more then sufficient. (for me anyway)
I don't know how anyone can get 6h out of 2300mAh. My 2 sets of 2500's get me through a 9h work day with not much to spare afterwards.

Read again, Ravnos ;) :)
 
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Kensupen posted on Feb 4 2006 at 11:32 AM said:
If you hook up 4.5v to a device designed to take 3-3.3v you WILL fry it slowly. It's basic electronics. You can get batteries that have as many amps as you can, but don't raise the voltage, or eventually it won't work at all with batteries.

-Kensupen

P.S. I took a 2 year cert in electronics, so I'm not just blowing wind in my sails.

Well he would only be hooking up 3.6v because each recharge able battery is only 1.2v. ;)


PS. I took a half year of Electronics one at my high school.

(sorry I could not help myself, I just could not pass that up.)
 
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reallynotnick posted on Feb 4 2006 at 12:59 PM said:
Kensupen posted on Feb 4 2006 at 11:32 AM said:
If you hook up 4.5v to a device designed to take 3-3.3v you WILL fry it slowly. It's basic electronics. You can get batteries that have as many amps as you can, but don't raise the voltage, or eventually it won't work at all with batteries.

-Kensupen

P.S. I took a 2 year cert in electronics, so I'm not just blowing wind in my sails.

Well he would only be hooking up 3.6v because each recharge able battery is only 1.2v. ;)


PS. I took a half year of Electronics one at my high school.

(sorry I could not help myself, I just could not pass that up.)

LOL Owned =p

But thanks for the warning.... it is a little over 3V isn't it? Hmmz...
 
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vossy posted on Feb 4 2006 at 05:55 PM said:
the word 'ansmann'

Seconded. Got some of their 2600mAh ones + their charger. Squidge recommended them in the forums so thought I'd give them a try.

Fantastic!

Mark
 
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Kensupen posted on Feb 4 2006 at 05:32 PM said:
If you hook up 4.5v to a device designed to take 3-3.3v you WILL fry it slowly. It's basic electronics. You can get batteries that have as many amps as you can, but don't raise the voltage, or eventually it won't work at all with batteries.
Well maybe, maybe not. I think the GP2X has a voltage regulator in there, so as long as it is within a sensible input range (definitely 2.4-3v, expect 5 is ok) it should be ok. But you'll find the power (VI) it takes is roughly constant.

Now if you put in 250V AC it will definitely fry:)

Mark

P.S. I have a degree in Microelectronics, but I can't remember any of it...
 
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jedthehumanoid posted on Feb 4 2006 at 10:50 AM said:
Ravnos posted on Feb 4 2006 at 07:38 PM said:
Silberstein posted on Feb 4 2006 at 09:50 AM said:
Ravnos posted on Feb 4 2006 at 05:06 PM said:
I think for NiMH rechargeables the voltage are pretty much the same across the board. You definitely need 2500mAh at least, though. I got a pack of these and they work great. There are better brands out there, but you'll have to dig for them and they'll probably cost more. You can probably find these at a local electronics store.

What do you mean you need 2500mAh at least!? How much do you guys play? I bought a recharger with four 2300 mAh batteries, and I don't think I've ever managed to use all that batterypower. Two sets 2300 mAh is at least 6 hours playtime a day, and that is more then sufficient. (for me anyway)
I don't know how anyone can get 6h out of 2300mAh. My 2 sets of 2500's get me through a 9h work day with not much to spare afterwards.

Read again, Ravnos ;) :)

Ahem. My bad. I'm obviously retarded. Look everyone! A distraction!

*runs away*
 
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Shikaku posted on Feb 4 2006 at 04:23 PM said:
Ravnos posted on Feb 4 2006 at 11:20 AM said:
Those should do fine.

Also, if you're referring to mail-ordering as being "close to the store", I've found it's usually just as cheap to buy in-store for most things (not SD cards though <_< ) once you factor in shipping.

Well, I mean literally I could walk into that store and buy it for the price that I see right here:

http://www.tigerdirect.com/applications/Se...1168668&CatId=0

But, I just found out something nice using the search feature...

Squidge posted on Dec 31 2005 at 01:20 PM said:
hmmm, lets do some idle tests in an attempt to find the optimal voltage :)

@ 2.5V = 410mA.
@ 2.9V = 340mA.
@ 3.3V = 300mA.
@ 3.4V = 290mA.
@ 3.6V = 280mA.
@ 3.7V = 270mA.
@ 3.8V = 260mA.
@ 4.0V = 260mA.

I think a battery capable of providing 3.7V is the winning one here. Who would have thought by just increasing the voltage by 1.3V, you would drop the consumption by 150mA ?

So, judging from these tests, for rechargable batteries, 3xAA (giving 3.6V) would give a LOT more playtime than 2xAA, simply due to the fact that the 2X doesn't have to waste as much energy to increase the voltage to it's preferred range.

Lets try this on mplayer:

2.5V - upto 850mA
2.9V - upto 690mA
3.1V - upto 650mA
3.3V - upto 590mA
3.7V - upto 530mA (270mA in stop mode)

Hmmm, a saving of over 300mA by just increasing the battery voltage. Nice :)

Now onto the search for finding higher voltage batteries xd

The GP32 (or any other electronic/electric device) does not consume mA, they consume watts. Wattts is equall to voltage * amperage (1000 mA = 1amp) Watts is energy So you are not wasting any energy at all using lower voltage.

So say you have a 1v device eating 1000 MA, the same device at 2v would use 500ma, but they both equal 1 watt (1000x1 or 500x2). Besides the gp2x most likely doesn't operate on 3 volts anyway, it most like higher. You can increase voltage with a transformer they same way you can decrease it.

Chris
 
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