3 Cell Battery Test

[nubie]

Here is what it looks like. I know it isn't attached or covered yet, but it IS a bench test.

I am doing this to see what the benefits there are in comparison to a regular 2 AA battery test, and maybe to see how it stacks up against the monster 3.6v Li-Ion battery pack in terms of portability, cost and user-friendliness.

3 fresh-charged Energizer 2500mAh NiMH and a 1xAA battery clip from Radio Shack ($0.99), with a couple new battery clips to run the power in series.

Link to Album: GP2X With 3AABatteries #1

Link to Album: GP2X With 3AABatteries #2

Just started battery tester and I hope it will be dead sometime today, chances are my 4 hours at work won't kill it, even with a 30 min commute both ways.

1.414 1.410 and 1.403 were the cells individual voltages, charged yesterday on the slow-charger.

The plan is to run a set of 3 through, then overclock as far as mine will go (or just 250), and run another set through. Then do a set of 2 both ways as well. I hope to see if the play-time is substantially increased (beyond the 50% more you would expect), possibly overclocks will work better too.

Edit, mods could you please change the title to "3 Cell Battery Test" or something similar? It just looks tacky right now. Thanks .

 

[chunkyktr]

will be watching with interest

 

[prairiefire]

Can't wait to hear how long this lasts. Also watching with interest!
cheers

 

[senquack]

Can't wait to see the results of this interesting experiment.

 

[nubie]

First impressions, I don't think the batteries are getting hot.

+1 for this mod , anything that keeps the batteries happier (less draw, less heat) will make them run longer, and live a longer useful life.

 

[bagmouse7]

Is that a battery in your pocket, or are you just glad to see me?





Sorry, I could not resist!

 

[thumpgun]

i always like a threesome....cough cough

 

[nubie]

Update:

Large (google web album)

6 hours straight and still going!! Batteries in the 2x are a bit warm, not as hot as they normally get. The external battery was maybe a degree or two above ambient, (69.8F 20.5C)

I'm kind of excited. A drop-in mod that replaces the back cover and the contacts can be done quite easily without opening the GP2X.

If you put contacts on the cover and made it to hold another cell it would be pretty darn cool. Then have another cover with a metal strip that just connects those contacts back up again and you can choose 2 or 3 cells at your leisure.

6 hours is crazy, you could watch 3 movies!!


Well, it does drop-off rapidly:

STATISTICS:
Clock Speed: 200 Mhz
Running Time: 6:17:38
Average FPS: 81.68

Current charge: 9%
Initial internal charge: 1023
Current internal charge: 674

6:17 is awesome though, especially on plain old Energizers that came with the 2X on ebay .

 

[nubie]

Final cell voltages after a few minutes rest:
1.165
1.154
1.144

 

[bhess]

I didn't know that just adding one battery would make such a difference!

 

[nubie]

It seems that if turn my score into what 2 cells should accomplish then I get 4:12

Unless my math sucks:

6 hours @ 60 mins + 17 mins = 377 minutes

377/3 = 125.6 single cell

125.6*2 = 251 for two cells

251/60 = 4 hours 12 minutes for two cells

4 hours 12 minutes is a good score for what I used:

1: 8 hours @ 360mAh timed charger.

2: 3xAA 2500mAh Energizers.

To run this way full-time with this charger requires at least 6 batteries, but you can get 8-packs with this charger included for ~$20-25. Cheap at the price for 6+ hours runtimes.

 

[Samba Pa Ti]

i wonder how many batterys could be 'forced' inside the back of the 2x vertically, i havent got it near right now to size up but i guess 6-8, a new gp2x back casing would be cool (with a huge battery compartment) it could still run off 2 batterys but if you wanted you could load it up with more

 

[nubie]

i wonder how many batterys could be 'forced' inside the back of the 2x vertically, i havent got it near right now to size up but i guess 6-8, a new gp2x back casing would be cool (with a huge battery compartment) it could still run off 2 batterys but if you wanted you could load it up with more

Yeah, I suppose. But if doing that spring for 3 cells that are just longer/bigger to reduce converting losses. Unless you want 4 just for 5 volts and USB .

What I am actually going for is the 3.7 volt sweet spot Squidge found with a bench power supply, where the internal DC-DC most efficiently makes the 3.3 volts the MMSP2 actually needs. This wastes less power than the current 2 battery cells.

5 hours so far @ 250mhz, but I need some sleep so I will probably check it in the morning.

 

[Samba Pa Ti]

would it be possible to wire 9 in series and parrallel then to keep it 3.7 volts but triple the mah rating (using 3 pairs of batterys)
id prefer the extra weight in the 2x and it should triple the amount of time the 2x can stay on (similar to what people said in the thunder power pack thread)

if you got 6:17 on 3 bats would you get nearly 20 hours using 9 ?

not sure how this would connect to the 2x but it should work like this

thx lint for pointing out the error in my diagram lol (fixed)

correct me if im wrong here im very tired (been up all night)

 

[Lint]

this should give you 2.4V 7.5Ah, the correct order for what you want is: 2 lines in parallel, 3 cells in each line
But damn, what do you want to play that much? <o>

 

[Samba Pa Ti]

id like to play it for a while without recharging : P

 

[nubie]

@ Samba,

Yes it should theoretically work, but as I said, just step up to 3x 13Ah commercial batteries (Edit: Here is a link to the 13Ah battery) and leave it there. It is probably just as hard to wire up the AAs and charge them all (unless the purpose is to use alkalines) as it would be to get some killer commercial batteries and use them.

The whole point of this is to leave the GP2X nearly unchanged, accomplished with a single AA. I thought of putting 3 more on the back but it would just be silly.

I have already slipped the original batter tab back in and the back cover, so the setup is zero impact, can't tell it has been done.

The 3.6 mega pack wastes the battery tray space, my plan aimed to use that space efficiently. 3x li-ion AA size cells with a controller will also accomplish the same at a lighter weight and longer run-time than NiMH. They would be in parallel though and need a controller sof some sort.

Here is the results of the second 3AA test:

STATISTICS:
Clock Speed: 250 Mhz
Running Time: 5:40:00
Average FPS: 101.70

Current charge: 100%
Initial internal charge: 1023
Current internal charge: 977

Not too shabby, close to 6 hours at 250mhz, PicoDrive CD here I come!

 

[toxic_d]

how about the possiblity of vacum molding a new back plate and putting the third battery inside the case... just a thought

 

[Samba Pa Ti]

i thought about this for a while, i cant find a cheap vacuum former anywhere (like i stated earlier id make it fit 4/6 batterys) probably best to use 6 bats since it hits the 3 battery sweet spot.

 

[DaveC]

@ Samba,

Yes it should theoretically work, but as I said at just step up to 3x 13Ah commercial batteries (Edit: Here is a link to the 13Ah battery) and leave it there. It is probably just as hard to wire up the AAs and charge them all (unless the purpose is to use alkalines) as it would be to get some killer commercial batteries and use them.

The whole point of this is to leave the GP2X nearly unchanged, accomplished with a single AA. I thought of putting 3 more on the back but it would just be silly.

I have already slipped the original batter tab back in and the back cover, so the setup is zero impact, can't tell it has been done.

The 3.6 mega pack wastes the battery tray space, my plan aimed to use that space efficiently. 3x li-ion AA size cells with a controller will also accomplish the same at a lighter weight and longer run-time than NiMH. They would be in parallel though and need a controller sof some sort.

Here is the results of the second 3AA test:

STATISTICS:
Clock Speed: 250 Mhz
Running Time: 5:40:00
Average FPS: 101.70

Current charge: 100%
Initial internal charge: 1023
Current internal charge: 977

Not too shabby, close to 6 hours at 250mhz, PicoDrive CD here I come!

Next test should be this:

http://www.batteryspace.com/index.asp?Page...amp;ProdID=2763

Use 2 of these in parallel. If it works I would mod my battery compartment. It actually doesn't have to be enlarged that much.

Now would you use 2 blocking diodes and resistors or just connect directly in parallel?