Battery Mod

[Eso Rimmer]

I found very interesting battery from Sanyo. It's lithium 3V@2500mAh ø17x45mm 22g. I think i should be easy to put 2 pieces of this battery into gp2x in parallel because of its dimensions. We could get 5000mAh. You can find it in GES Electronic What do you think?

EDIT:
sorry for double post. I post this topic to News section by my mistake.

 

[darkplayer]

wouldnt 6v be to much for the gp2x?

 

[1101]

I think by "put 2 pieces of this battery into gp2x" it is ment that the battery be cut up. Cutting up acid-filled balls of electricity? - sounds like fun. It does seem like a good idea, but don't most things at some time?

Good luck with this one, you might end up selling the things if it works any good.

 

[parag0n]

AFAIK, lithium batteries are non-rechargable.

 

[PokeParadox]

Laptop batteries are usually lithium ion...

 

[ihate56k]

"wouldnt 6v be to much for the gp2x?"

He said paralel, not series.

are people really finding the battery life so bad on the gp2x? I carry around a couple of changes of batteries, can't say I've been to bothered by it.

 

[Squidge]

Hmmm, is this battery actually rechargable?

 

[FluffyPanda]

I found very interesting battery from Sanyo. It's lithium 3V@2500mAh ø17x45mm 22g. I think i should be easy to put 2 pieces of this battery into gp2x in parallel because of its dimensions. We could get 5000mAh.

​

Should work. I get perfectly good life out of my 2500mah batteries so I wouldn't personally bother, but in theory it shouldn't be too hard to do.

Have you opened your gp2x yet? The battery contacts look really easy to mod.

 

[Vimacs]

putting rechargeables in parallel is not a good idear.
you will have to add a aditional voltage converter to get the 6v down to 3v

 

[Hanz™]

Hmmm, is this battery actually rechargable?

​

No.

 

[aapje89]

Hmmm, is this battery actually rechargable?

​

No.

​

lol, but if it was/is it would be a good idea

@Vimacs: you smartass

Edit: indeed they arent rechargeble

 

[Aimless_E]

At the risk of being laughed at I had a dream last night about my gp2x.

I dreamt that I made a wrist band filled with recargable lithium ion batteries that pluged into the AC plug on the side of the gp2x. It came complete with a retractable cable both for the gp2x and to plug in to recharge the batteries.

Pretty gay huh?

 

[FluffyPanda]

At the risk of being laughed at I had a dream last night about my gp2x.

I dreamt that I made a wrist band filled with recargable lithium ion batteries that pluged into the AC plug on the side of the gp2x. It came complete with a retractable cable both for the gp2x and to plug in to recharge the batteries.

Pretty gay huh?

​

Depends how you interpret the "retractable cable" and the penetration of the GP2x by such a metaphor.

I think Freud would probably have had a good time on that one.

(oh, you mean dreaming about your gp2x? )

 

[Aimless_E]

At the risk of being laughed at I had a dream last night about my gp2x.

I dreamt that I made a wrist band filled with recargable lithium ion batteries that pluged into the AC plug on the side of the gp2x. It came complete with a retractable cable both for the gp2x and to plug in to recharge the batteries.

Pretty gay huh?

​

Depends how you interpret the "retractable cable" and the penetration of the GP2x by such a metaphor.

I think Freud would probably have had a good time on that one.

(oh, you mean dreaming about your gp2x? )

​

Well Freud saw sex in everything, but even so sometimes a plug is just a plug.
That and I always imagined my gp2x would be a sexy redhead with a give it all, but don't take no crap aditude.

But thats me

 

[reaper79]

putting rechargeables in parallel is not a good idear.
you will have to add a aditional voltage converter to get the 6v down to 3v

​

Incorrect:

Batteries in parallel doubles the capacity (mahs). Two 3v batteries in parallel is still 3v, so it is fine. Two 3v batteries in SERIAL would be 6v.

Reaper

 

[abigsmurf]

Having modded three lithium polymer cells in parallel for the unit it most definately works and is safe. The risk when putting lots of cells in parallel is that they drain at very slightly uneven rates, which can potentially result in reversing of current when charging or at low power. Most decent battery suppliers integrate protection circuits into their cells though.

One thing with those AA-ish sized lithium cells is that they're a pretty tight fit as it is, let alone when blocking the rear contacts (so you don't fry the unit by having the cells in parallel) and connecting the batteries in parallel. cutting out or filing the battery compartment may be required

 

[Eso Rimmer]

Ouch, they aren't rechargable? I thought they are. Sorry, shame on me...
Yes, there it is http://www.abcde.de/data/cr17450se.pdf

It was too good to be true.

 

[peter.stegemann]

Having modded three lithium polymer cells in parallel for the unit it most definately works and is safe.

Does this mean you already did that or just that you think it is safe?

If it is the latter: Please try it on your own for some time and suggest it afterwards. The LiPo cells have way higher voltage (3.7V) that could damage the device on a short or longer term.

Next problem is that the gp2x has no "cutoff voltage" that fits the LiPo cells - discharging such a cell below 3.0V will quickly damage it (some survive even 2.7V, but the gp2x will even go below that).

If the gp2x would have been designed for 3 NiMH cells (3.6V), this could be done much easier.

The risk when putting lots of cells in parallel is that they drain at very slightly uneven rates, which can potentially result in reversing of current when charging or at low power.

This is not possible for parallel cells. They always stay on the same voltage level. So even if they have different capacities, they will be empty "the same moment". If the voltage is different when connecting them to each other, they equalize. Depending on the different charging level, this could result in a high current flowing between the cells. But normaly that one does not damage anything - just don't connect fully charged and empty cells anyways.

I'm not sure what you mean by "reversing of current". But if you refer to the problem that cells reverse their voltage when "over-discharged" in a pack, this can't happen with LiPo cells. They just pass away when their voltage drops too low. If it goes to high, they often simply blow up...

 

[abigsmurf]

Yeah I've actually done the mod and it works fine (hasn't blown up yet at least). The 3.7V doesn't seem to matter as the unit appears to have an internal voltage regulator. It works out as more efficient as you need less current (so you get less heat).

When I was researching multicell packs I came across a number of warnings about uneven charging and discharging although it was mainly when there were a large number of cells in parallel. Electricity will always take the path of least resistance and if there's a big enough difference in the amount of power left in cells, it can end up being a cell next to it rather than the circuit itself and causes all sorts of issues.

As I said though, with protection circuits in the cells it shouldn't be an issue

 

[adgloride]

The one mistake they made with the gp2x is not supplying some sort of rechargable batter pack like all the new handhelds have.