Battery Life

[jmetal88]

You can't use NiCD at all. The voltage is too high.

Eh? All my Nickel Cadmiums are 1.2v.

 

[westwoodek]

How does Ni Cd rate to Ni MH ?

Avoid it.



Will this Ni Cd charger charge Ni MH (methinks not) ?

No



What sort of package should I buy that gives me a NiMH charger with 4 batteries that will give me about 4-5 hours of play (top of the range super duper wooper does not apply lol) ?

Energizer 2500's
Walmart has a pack w/charger cheap. These are the batteries I use, getting ~4-5 hours per charge.

Yeah,30 quid,thatll do

 

[BradN]

You can't use NiCD at all. The voltage is too high.

Eh? All my Nickel Cadmiums are 1.2v.

The problem isn't the battery voltage, it's how the charger goes about charging it (he was asking if it was safe to charge NiMH in a NiCd charger) - the NiCd chargers typically will over-charge NiMH batteries (NiCd is much more tolerant to overcharging), likely shortening their life. If you're very careful and know exactly how long to leave it in the charger, you're probably safe, but it's just not worth the trouble.

The best way to go is getting an advanced charger with capacity readout and nice features like that. It allows you to match up batteries that have very close capacities and get more runtime out of them, as well as prolonging the life of the batteries.

 

[Lint]

The problem isn't the battery voltage, it's how the charger goes about charging it (he was asking if it was safe to charge NiMH in a NiCd charger) - the NiCd chargers typically will over-charge NiMH batteries (NiCd is much more tolerant to overcharging), likely shortening their life. If you're very careful and know exactly how long to leave it in the charger, you're probably safe, but it's just not worth the trouble.

The best way to go is getting an advanced charger with capacity readout and nice features like that. It allows you to match up batteries that have very close capacities and get more runtime out of them, as well as prolonging the life of the batteries.

All NiCd chargers I've ever saw were capable of charing NiMH, in fact, both NiCd and NiMH 'slow' chargers are pretty much the same circuit, wich is a 2.8V (+/-) current-limited power source, simple as that... the only difference is that NiMH chargers use to allow more current (as NiMH hold more energy) so one NiCd battery on a NiMH is likely to explode while a NiMH battery on a NiCd charger will just take a lot of time to charge (sometimes even more than a day to fully charge)

as a rule of thumb, you should not exceed 0.1C as charge current (so, 150mA chargers will charge batteries from 1500mAh to more, within more time..), then you're safe to charge forever (altough not advised to do so) as the battery is not going to blow
by using a 200mA NiMH charger in a 1000mAh NiCd battery, you're charing 0.5C, there's no problem of doing that if you don't leave the battery charging after it's full, but once it's full it will get hotter until explode

quick chargers are absolutely different, as they rely on feedback from battery (temperature and current, mainly)
and no, no charger has any idea of how much capacity your battery can have, they just get guided by the batteries' voltage and it's actual current consumption.. (closer to full -> bigger the charging internal resistance)

And be really careful about this: no, NiCd batteries are NOT more overcharge-tolerant than NiMH as I've already blown 2 NiCd overcharged batteries in my bare hands :rolleyes:

 

[White Demon]

I got 2500mAh Energizers with the dumb charger that takes 15 hours to charge. After the charger turns off, I stick 'em in my GP2X and get:

4 hours 20 min @ 200mHz
3 hours @ 250 - 266 mHz
approx 7 hours @ 100 mHz (mp3)

 

[BradN]

http://www.batteryuniversity.com/partone-11.htm

The caution applies especially to nickel-metal-hydride because this chemistry cannot absorb overcharge well.

...

Nickel-metal-hydride should be rapid charged rather than slow charged. Because of poor overcharge absorption, the trickle charge must be lower than that of nickel-cadmium and is usually around 0.05C. This explains why the original nickel-cadmium charger cannot be used nickel-metal-hydride.

If you overcharge (or charge too fast) any battery to the point that it can't dissipate the heat well enough or too much internal pressure builds up, it'll go pop or vent some of the evaporated electrolyte (depending if the safety valve actually works). The extra problem with NiMH is that a somewhat low trickle charge can damage the battery even without the more obvious symptoms. But you're right in that the normal charging for NiMH can be done (perhaps even should) at a higher rate.

 

[JaqMs]

I got 2500mAh Energizers with the dumb charger that takes 15 hours to charge. After the charger turns off, I stick 'em in my GP2X and get:

4 hours 20 min @ 200mHz
3 hours @ 250 - 266 mHz
approx 7 hours @ 100 mHz (mp3)

Edit: Apparently my statement was offensive.

 

[Ranma13]

The processor specs should be falsely described so that devs optimize their emulators (sigh) to run at 200 mhz, not overclocked at 250 and above. That way, everyone saves battery life.

Why hasn't this guy been banned yet?

 

[jdwrrzmm]

Duracell 2500 mAh 200mhz: Nearly 4 hours. The test I did it lasted 3 hours and 58 minutes.

 

[jislizard]

I got through 4 sets of batteries to watch one film yesterday.

I have no idea as to why this is, maybe too much processing for the GP2X due to the high quality of the films, they are still about 400mb.

The batteries are energiser 2500mAh NiMH, 1 month old that came with a charger that takes 15 hrs to charge them fully and I drain them on my Gameboy advance before I recharge them.

After about 20 mins the GP2X freezes, I can take the batteries out and run them for at least 2 hours on my GBA with a glowguard light attached.

I wil try double charging them as advised above but seeing as they work fine in my digital camera is there any reason that the GP2X should be draining them so quickly? I am using the latest firmware and the batteries are new but have had a few cycles and I drain them before each use.

I use it mostly attached to the power supply at the moment which defeats the purpose.

It's either a battery problem or a battery charger problem or a GP2X problem.

I have 2 types of battery, the other type being RGB 2100mAh and a charger that came with them so it is looking like it is the GP2X, the most expensive thing to change, typical.

 

[Epicenter]

Always play video that is natively 320x240. If it is not this resolution the GP2X must scale it, and the scaling units use loads of power.

 

[Bloodsack]

I use ansmann 2600 that I bought with my gp2x at gp2x.co.uk and they work great. 5 hours at least with video.

 

[jlong]

This is how I got many hours of use on the GP2X.
For this charger:

and these batteries:

I am getting 10 hours per 2 batteries, with movies, and neogeo at 280 oc.

 

[Bloodsack]

damn!!! 10 hours

I wonder If I can find those batteries in the UK jlong?

 

[xinfernoofdantex]

i dont believe that at all.....

 

[Intruder]

Hello folks,

Well I also went thru some batteries set rather quickly while watching some anime episode. Those were encoded in 640x480, in good quality. And I am getting about 1h30 with my energiser 2500mah right now.

So from reading different post it seems those battery life look normal for running high video, is it possible to still sqeeze a little bit more in that resolution? Or do I really need to rescale them to 320x240 like Epicenter is saying? Bloodsack said he got 5 hour by playing video, playing NeoGeo, etc... maybe it is only some low resolution video?

Thanks.

Sincerly
Fred

 

[Shikaku]

320x*anything* is fine, the scaler won't work if it is at that resolution...

 

[daclassicgamingmaster]

This is how I got many hours of use on the GP2X.
For this charger:

and these batteries:

I am getting 10 hours per 2 batteries, with movies, and neogeo at 280 oc.

DAMN, 10 hours!!?

I gotta get some new batteries.....

 

[Intruder]

Shikaku :

So you are also watching your video in this kind of resolution? How much time does the batteries last if played in that kind of resolution?

Thanks.

Sincerly
Fred

 

[Dimacus]

Intruder, just so that you know, even if your videos would be encoded at 1024x768 the internal scaler makes them into 320x240, so there is no visual difference in videos encoded at 640x480 and 320x240 unless you use TV-Out.