Battery Mod Anyone?

nubie

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OK, I'll bite, I love these :):
http://www.batteryspace.com/index.asp?Page...ROD&ProdID=2013

I don't see the "built in" protection IC's, Interesting if they are inside the cells, that is cool.

I also notice that the AA size is 750mAh at 3.6volts, two of them in parallel make only 1500mAh.

I don't know, 3.6volts is nice, but I feel I would lose out, my energizers do 2500mAh as it is.

I thought Li-Ion couldn't drain as low, or charge as high, so you are nominally working between 20% and 80% of battery (call it 20% to 90%) or whatever it is.

I understand that longer shelf life is nice, but if you play regularly it doesn't become an issue.

Would a PSP pack fit in? They come in 2600mAh.
 

OmarNawaz

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nubie posted on May 26 2006 at 11:26 AM said:
OK at I'll bite at I love these :):
http://www.batteryspace.com/index.asp?Page...ROD&ProdID=2013

I don't see the "built in" protection IC's, Interesting if they are inside the cells, that is cool.

I also notice that the AA size is 750mAh at 3.6volts, two of them in parallel make only 1500mAh.

I don't know, 3.6volts is nice, but I feel I would lose out, my energizers do 2500mAh as it is.

I thought Li-Ion couldn't drain as low, or charge as high, so you are nominally working between 20% and 80% of battery (call it 20% to 90%) or whatever it is.

I understand that longer shelf life is nice, but if you play regularly it doesn't become an issue.

Would a PSP pack fit in? They come in 2600mAh.

lithium mah rating are diffrent to our recharables even though they are 750 they last longer

someone who knows more will explain
 
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___

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that battery pack that nubie suggested seems pretty cool. I think that could extend the gp2x uptime a lot. I wonder though if it is possible to connect the pack directly through the battery compartment since it is 3.6V... I know that the gp2x can take up to 3.6V but is this really a smart thing to do? Batteries add up to 3V normally...
 

Squidge

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I've connected a PSU to the battery compartment and powered it with 4v. Nothing bad seemed to happen. The GP2X still lives.

I did notice however that at 3.7V, the 2x used less power than when at lower voltages, so it would make sense to assume that a certain amount of power is wasted to increase the voltage of the battery output to somewhere around this voltage.

If I can find the batteries in a more local store (I'm in the UK) then I'll certain be having a go myself, but ordering from the US wouldn't be quite so practical.
 

OmarNawaz

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yeah them being in the us is a real bitch

might just test out their service though see how reasonable they are
 

lippy

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Wite_Noiz posted on May 26 2006 at 04:32 PM said:
Squidge at what about these: http://www.rapidelectronics.co.uk/rkmain.a...62244&XPAGENO=1

Not sure these are the same things, but Rapid are an electronics supplier in the UK, so shipping's easy ;)

My GP2X hasn't arrived yet *sobs* so I haven't bothered with expensive batteries until I know how long to expect from my current 2.5's.
I'm don't think they're rechargable
 
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Squidge

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lippy posted on May 26 2006 at 05:10 PM said:
Take a look at this: Ebay batteries These look like the same ones, at it's quite cheap: 8 for £20 shipped
Item location: SF, United States

Ebay is also the perfect place to get scammed. Remember people complaining about those 4gb SD cards that only format to 1gb?
 
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lippy

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Squidge posted on May 26 2006 at 07:23 PM said:
lippy posted on May 26 2006 at 05:10 PM said:
Take a look at this: Ebay batteries These look like the same ones, at it's quite cheap: 8 for £20 shipped
Item location: SF, United States

Ebay is also the perfect place to get scammed. Remember people complaining about those 4gb SD cards that only format to 1gb?
Yeah I know, but the guy who sells this only sells batteries, has sold over 34000 batteries, has 99.3% rating. It's hard denying the facts. Plus with the exchange rate so low nowadays, i reckon it's pretty good.
 
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OmarNawaz

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I havent used theses suppliers but I have nearly completed my battery mod

I running off a sony camcorder battery 7.2v

Im feeding the GP2X 5V and it seems okay im doing stress tests and battery life tests tomorow

Ill be using that 5v for something very useful ;)
 

DaveC

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I havent used theses suppliers but I have nearly completed my battery mod

I running off a sony camcorder battery 7.2v

Im feeding the GP2X 5V and it seems okay im doing stress tests and battery life tests tomorow

Ill be using that 5v for something very useful ;)

Why not just add a resistor to drop the voltage down to 3V? Why beat on the electronics and potentially shorten the lifespan?
 
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OmarNawaz

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I havent used theses suppliers but I have nearly completed my battery mod

I running off a sony camcorder battery 7.2v

Im feeding the GP2X 5V and it seems okay im doing stress tests and battery life tests tomorow

Ill be using that 5v for something very useful ;)

Why not just add a resistor to drop the voltage down to 3V? Why beat on the electronics and potentially shorten the lifespan?
a resistor :blink: a resitor you can use resistor to drop 7.2v to 3.3v wouldnt that be like a big waste of energy even if you find this crazzzy resistor

but yeah i see what you mean i had a dc/dc converter hooked for 3.3v but no room then i cooked the damn thing

The gp2x has a built in converter anyway so it shouldnt hurt it too much apart from heat

Im waiting for some 33v converter for another peroject im doing ill probaly wack that in there when i get it will save the battery a bit as its more efficient

the 7805 gonna be needed anyway for the usb port its a pretty cool one shuts down when it overheats
 
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BradN

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You could only use a resistor to drop the voltage like that if the load device has constant resistance. The GP2X doesn't - it varies a huge amount depending on processor usage and whether the TV encoder is enabled or not, etc.

Besides, if it runs on 5V (which the datasheet for the internal regulator seems to say it can), it'd be more efficient than running it at 3.3V, especially if you're using linear regulators (like the 7805, which pretty much acts like a variable resistor to regulate the voltage) to provide the input. In theory, with a 7.2V battery, you'd be wasting 30% (2.2/7.2) of the power by using a 7805, but if you wanted 3.3V, you'd waste 54% (3.9/7.2).

Switching regulators like the GP2X has internally get into the high 90%'s for efficiency, so if you've got enough motivation to wire one of those up, that'd really be the best way to go.
 
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