Battery Life On Gp2x

[iignotus]

Hello all, I've finally gotten around to doing what I've been meaning to do for some time now. I've performed a somewhat formal test on the (my) gp2x's battery life. The test was performed with 2x Energizer 2500mAh AA NiMH Batteries. They closely resemble these:

They were freshly charged on the slow (full) charging method of my Maha AA/AAA charger after having been charged and discharged many, many times through normal use (mainly with my gp2x). This is the charger:

I tried to do a normal run of what the average game-player would do with their gp2x. I didn't do any movie-playing, so this test was performed without any second processor usage. There are times when I left the game running (not the menu, though) as I stopped and did other things, though the processor load doesn't really change. I'm on firmware 2.0.0 and I didn't utilize TV-Out, headphones, a breakout box, or anything else. Just me and my gp2x, running on batteries.

Here is the table of times and what I did with my gp2x after popping them in directly from the charger. Time is in hours:minutes standard clock time during the afternoon, just in case you cared

3:24 - Turned on GP2X
3:25 - Started DRMDx @ 200mHz with Sound
3:42 - DRMDx froze Power cycled GP2X.
3:43 - Started DRMDx again.
5:09 - Exited DRMDx.
5:10 - Started GnGeo2x with the Rage2x frontend @ 200mHz without Sound.
5:25 - Left to eat dinner and take a shower GP2X still on and in a NeoGeo game, of course.
7:06 - Came back to find my GP2X frozen again However, it was not dead. Power cycled.
7:08 - Started the newest DR-Squide'sSNES @ 200mHz with Sound.
7:40 - Super Mario 2 froze... batteries dead!

The GP2X lasted 4 hours and 16 minutes with general use.

I plan on adding this bit to the GP2X wiki, but if someone wants to beat me to the punch and give me a link to their changes, I'd love it. Any and all comments are welcome. I plan on testing other types of batteries later, but I chose these kind first because they are frequently touted (by me including) as cheap, efficient batteries for everyone's favorite console.

 

[Epicenter]

Before you go putting that on the Wiki, you should do this again after discharging the batteries 100%-- that is to stay, let the GP2X crash, then let the screen backlight die, ensure nothing is still on the now-dim display .. then take the AAs out and put them in a GBA or a CD player, etc.-- something that will run until the batteries are entirely depleted-- and let THAT go until it's dead. Odds are a GBA can still run on those GP2X-depleted cells for a whole night. Maybe longer. After my digital camera starts refusing AAs they will power my GBA for over 20 hours on average.

THEN recharge them to their maximum capacity and give it another whirl.

At any rate, good initiative, looking forward to seeing your results.

 

[iignotus]

Before you go putting that on the Wiki, you should do this again after discharging the batteries 100%-- that is to stay, let the GP2X crash, then let the screen backlight die, ensure nothing is still on the now-dim display .. then take the AAs out and put them in a GBA or a CD player, etc.-- something that will run until the batteries are entirely depleted-- and let THAT go until it's dead. Odds are a GBA can still run on those GP2X-depleted cells for a whole night. Maybe longer. After my digital camera starts refusing AAs they will power my GBA for over 20 hours on average.

THEN recharge them to their maximum capacity and give it another whirl.

At any rate, good initiative, looking forward to seeing your results.

I had already put them into my camera when I got them. It doesn't draw much power and batteries from a dead gp2x last about an hour in my camera. I would figure that's about as drained as they're going to get, since all my remotes take AAAs and I lost my GBA and CD Players long ago I'll try to find something, though -- no promises.

 

[Epicenter]

Mm, a camera probably won't do too good a job as it won't provide a sustained power draw, and will probably shut down when the batteries drop below usable levels. At least find a CD player or something. Or just rig up a little frankenstein creation with a small light bulb and the AAs and run it til the bulb goes out ..

 

[iignotus]

Well look at the relic I found

My only fear is that I'll be waiting days for them to die!

 

[Intruder]

Well ill go with the simple trick that Epicenter, I was going to suggest the same thing ;-). Simply link up several light bulb together (small one that can powered by battery of course hehehe). Then connect it and leave it like this until the light is out. I did that for my NiCD battery for my RC cars ;-), want to make sure they are fully discharge before charging them again.

 

[Epicenter]

Probably not. Maybe a night or 14 hours or so ..

 

[Lint]

According to NiMH batteries maker GoldenPeak ( http://www.gpbatteries.com.tw/html/battery...chargeable.html ) it's better to not let the batteries discharge much beyond the point wich common devices refuses to work

So I don't know if it's a good idea to cycle so deeply batteries..

 

[iignotus]

According to NiMH batteries maker GoldenPeak ( http://www.gpbatteries.com.tw/html/battery...chargeable.html ) it's better to not let the batteries discharge much beyond the point wich common devices refuses to work

So I don't know if it's a good idea to cycle so deeply batteries..

Well the GP2X isn't a very common device, is it?

Ah, I don't know who to believe. I doubt any of this will make more than a 5-10 minute difference in my next test... eh.

 

[sparr]

When my expensive electronics say my batteries are dead i demote them to remote control duty, where they usually last 2-3 more weeks before being destined for the trash or recharger, depending*.

* - Circuit City had 48-packs of Maxell AA batteries on sale for $5 the day after Thanksgiving. I bought excessive amounts. I am using more non-rechargables now than is my usual habit, just because they are handy.

 

[BradN]

The problem with fully discharging batteries like this is when you discharge more than one in series - the same current has to flow through each, and if they don't have the exact same capacity (which they probably don't), one will end up fully drained while the other is still charged, and the one with power left will start to reverse charge the other battery until it's at the same (negative) voltage as the other one, which can damage it. It should be safe to completely discharge cells separately though.

 

[FluffyPanda]

Strange though. Back when I had FW 1.4.0 on I left 2 fully charged Energizer 2500 batteries in and DrMD playing the sonic title screen and it llasted for 5 hours one minute.

My charger is an energizer branded overnight model and takes about 12 hours to charge 2 or 4 batteries.

Surely the latest firmware should last slightly longer, not 45 minutes less. I wonder if your charger is really getting the best out of your batteries.

 

[DTH]

Is it really such an unstable system, since in crashes all the time? :S

 

[subin]

Is it really such an unstable system, since in crashes all the time? :S

i've never had it crash on me. i guess i don't use it for extended periods - my thumbs start hurting after a while

 

[RyokoSparda]

I've got Energizer 2500 mAh NiMH and they don't last as long as my Uniross which are the same type and MAh, but then they never seem to fully charge in my Uniross charger, it says they are charged but then if you unplug the charger and plug it back in it starts charging again for ages, something it doesn't do the Uniross ones, buts it's the only way to get a good charge into them.

 

[chrono]

Is it really such an unstable system, since in crashes all the time? :S

i've never had it crash on me. i guess i don't use it for extended periods - my thumbs start hurting after a while

Has anyone tried the new lithium AAs that Energizer makes?

 

[noreason]

i have just charged my batteries and over some minutes i will start the payback rolling demo and count how long the batteries will last in it...

edit: payback demo is now running for 1 hour and 5 minutes, i begin to hate that music

OK...
My batteries were: MaxCell 2700 MAH chareged with a rapid charger

after 2 hours and 10 minutes: red light
after 2 hours and 17 minutes: music stop and screen dizzy... the end

 

[Epicenter]

The system isn't unstable; but very early software is imperfect. Even more so than how .. well, all software is imperfect.

NiMH batteries develop a 'memory', they are famous for it. If you have a 100% charged NiMH cell and you use it with the GP2X and drain it to say, 30% when the GP2X stops being usable (voltage level drops too much) then recharge it .. it will only last as long as 70% of its capacity! Discharge it again and it will next time, charge to about 40% capacity .. then 10% .. so forth. Eventually the batteries will appear useless! This is why you must discharge FULLY and recharge FULLY to restore full life of the batteries-- if you don't charge fully ASAP you will only see how much capacity you charged to, and a new memory will be established .. annoying, huh?

This is why I am so adamant about it. I averaged 5-6 hours of life on my Energizer 2500MAh AAs. After 5 cycles of letting the GP2X drain them til it crashed then recharging them immediately (Due to time constraints) .. they now last 1 hour! Sometimes less! I need to completely empty them in my CD player when I get back home, this reminds me.

Also, I'd use an 8-hour plus charger like mine. The ones that do a full charge in about 15 minutes reportedly charge the cells only to ~70%. This compounded with the NiMH "Memory Effect" will result in some pretty abysmal performance.

 

[White Demon]

I also use energizer 2500mah rechargables, and after 2 cycles in my GP2X, I stick them in my Sony Walkman and let them deplete as much as that will allow. My charger is also a 15 hour charger too.

The first time I got the batteries I ran my GP2X at 200mHz with all apps, and it lasted 4 hours and 20 minutes. I was on fw1.4 at the time.

Now, with fw2.0 and everything else the same, I still get 4 hours 20 minutes and no more. As I said, I completely drain the batteries after every 2nd recharge.

So my findings have always been the same as iignotus's with general 200mhz use.

 

[bbodin]

The system isn't unstable; but very early software is imperfect. Even more so than how .. well, all software is imperfect.

NiMH batteries develop a 'memory', they are famous for it. If you have a 100% charged NiMH cell and you use it with the GP2X and drain it to say, 30% when the GP2X stops being usable (voltage level drops too much) then recharge it .. it will only last as long as 70% of its capacity! Discharge it again and it will next time, charge to about 40% capacity .. then 10% .. so forth. Eventually the batteries will appear useless! This is why you must discharge FULLY and recharge FULLY to restore full life of the batteries-- if you don't charge fully ASAP you will only see how much capacity you charged to, and a new memory will be established .. annoying, huh?

This is why I am so adamant about it. I averaged 5-6 hours of life on my Energizer 2500MAh AAs. After 5 cycles of letting the GP2X drain them til it crashed then recharging them immediately (Due to time constraints) .. they now last 1 hour! Sometimes less! I need to completely empty them in my CD player when I get back home, this reminds me.

Also, I'd use an 8-hour plus charger like mine. The ones that do a full charge in about 15 minutes reportedly charge the cells only to ~70%. This compounded with the NiMH "Memory Effect" will result in some pretty abysmal performance.

I don't think this is accurate at all. NIMH's don't have nearly the 'memory' of the other type battery (who's name escapes me). I'm not saying there is no memory or need to discharge them, but it's not nearly as drastic as you describe. In fact NIMH are 'famous' for NOT having this memory (it's the other types that's 'famous' whose name escapes me again) .

Most people recommend draining NIMH batteries fully about every 10 or so uses. I'm able to use NIMH batteries repeatedly without full discharge and get similar usage each time. But after about 8-10 useages I do start to notice a loss of performance.