Batteries

[Flavor]

The GPA is designed to use Lithium-Ion (LiIon) or Lithium-Polymer (LiPo). Do not use the GPA to charge NiMh or NiCd cells.

I thought I'd start a thread to post some battery test results in the hopes that other people may chime in. My tests usually involve booting up the GPA, starting a game, and leaving it in attract mode (full volume using the external speaker) until the batteries die. I have a script that runs at bootup that will write the time to a file every 2 minutes (in case I don't notice when it dies).

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These tests were done on a GPA v1 board modified to use the Adafruit PowerBoost 1000c. This is meant as a test to simulate the GPA v2 board.

Marked “3.7v 600mah 25c” (http://www.ebay.com/itm/321929397097)
Single Cell TEST 1: 1h 48m 108m
2 Cells in Parallel TEST 1: 3h 43m 223m
2 Cells in Parallel TEST 2: 3h 44m 224m

500mah Adafruit (https://www.adafruit.com/products/1578)
Single Cell TEST 1: 1h 05m
Note: This cell is small enough to fit 2 in the AA compartment of the GPA (wired in parallel). In fact, with some modding, I think maybe 3 could fit. Multiplying the number of cells by the TEST 1 time would give a good rough estimate of play time.

14500 marked “2300mah” (http://www.ebay.com/itm/172344943423)
Charged using wall charger
2 Cells in Parallel TEST 1: 1h 25m
2 Cells in Parallel TEST 2: 1h 28m

14500 marked “2500mah” (http://www.ebay.com/itm/252204140454)
2 Cells in Parallel TEST 1: 1h 40m

3.7V 750mAh Battery For MJX X300C X400 X500 X800 Quadcopter (http://www.ebay.com/itm/281916864511)
Single Cell TEST 1: 1h 36m

Sanyo UR14500P 840mAh 3.7V - Unprotected 14500 Li-ion Battery (http://www.ebay.com/itm/112130942311)
2 Cells in Parallel TEST 1: 3h 26m
2 Cells in Parallel TEST 2: 3h 26m
Note: These cells are the same size as AA batteries, and it's likely that (based on these results) they are what we will be recommending people use. They will likely require a single wire to be run, but then they will be easily usable/replaceable.

1200mAh Li-po Battery for Syma X5SW X5SC RC Quadcopter S1P5 (http://www.ebay.com/itm/401165612472)
Single Cell TEST 1: 2h 20m
Single Cell TEST 2: 2h 26m
Note: This cell seems as if it would fit in the AA compartment with some fairly minor modifications to the plastic, but I haven't tried fitting it in.
2 Cells in Parallel TEST 1: 5h 10m
Note: I think you could likely fit 2 of these in your GPA if you cut the entire bottom out of the AA compartment.

1000mAh 753050 Cells (tested using GPA v2.0) (http://www.ebay.com/itm/172600979306)
Size: 7.5x30x50mm each
Single Cell TEST 1: 2h 24m
Single Cell TEST 2: 2h 35m
Single Cell TEST 3: 2h 38m
A stack of 2 of these cells fit very nicely inside of the AA compartment with very minor mods to the plastic and should last over 5h. At the moment, these are our favorite flat-pack style cells.

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These tests were not done by me, and they weren't done on a GPA, but they are very relevant.

Over at https://retropie.org.uk/forum/topic/960/neopigamer/75, mrvanes has posted some 14500 test results. If you look up higher (older) in that thread, we discuss some specific 14500 brands and such.

Here are the results of the long overdue AA stamina tests of the Trustfire 900's:

Load: NES Donkey Kong Classics Demo mode (start, then leave it alone).

GBA Zero (2 AA's, 3.2" PiTFT, USB hub + USB audio)
Old pack: 1.37:08
Trustfires: 3.21:00 (207%)

GB Zero (4 AA's, 2.8" PiTFT, USB hub + USB audio + USB Teensy + USB Wifi)
Old pack: 2.16:54
Trustfires: 4.36:00 (202%)

So, conclusive it's safe to say that over 3 hours of gameplay are possible on a GBA Zero using 2 Li-ion AA's.

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I believe that the results mrvanes posted show that the tests I did with my as-cheap-as-they-come 14500 cells would be improved by ~2x if I used top-of-the-line 14500 cells.
UPDATE: I think this theory is even further solidified with the addition of the "Sanyo UR14500P" test results.

[oolunchbox]

With a partial charge, I was able to get 2hrs 12 min using the Lithium Ion Battery - 3.7v 2000mAh from Adafruit. I'll try for a test from a full charge over the weekend.

I tested by starting Marvel Super Heroes: War of the Gems (SNES) and letting the demo run.

Excessive modification to the shell was required to make this fit. This includes having to cut the clip off the battery door. I'm currently using masking tape to hold it on while I work on finding a better solution.

[oolunchbox]

With a partial charge, I was able to get 2hrs 12 min using the Lithium Ion Battery - 3.7v 2000mAh from Adafruit. I'll try for a test from a full charge over the weekend.

I tested by starting Marvel Super Heroes: War of the Gems (SNES) and letting the demo run.

Excessive modification to the shell was required to make this fit. This includes having to cut the clip off the battery door. I'm currently using masking tape to hold it on while I work on finding a better solution.

I just got 5h 15m from a full charge. As before, I tested by starting Marvel Super Heroes: War of the Gems (SNES) and letting the demo run.

[carol039]

I just received my GPA v2 kit in the mail. This may be a stupid question but does the version2 board support charging of the 14500 cells through the board or is it just the li-ion battery packs?

also would these batteries work? It says it has some protected pcb and idk if that would effect it at all?

https://www.amazon.com/EcoGear-FX-Rechar...on+Battery"

also i was doing some research trying to find the right kind of batteries I want to use and I found a few people talking about how unprotected li-ion cells are dangerous and can explode? is this something i should be concerned with or not?

[Flavor]

Yes, you are right to inform yourself about the dangers. You should get protected cells if you can. The only issue with the cells you listed from Amazon is that the protection circuit adds a little length to the battery. It will be a very tight (maybe impossible) fit in the AA compartment unless you make some shell mods to accommodate them.

I do think the cells you mentioned would work well, but the length may be a concern. I have some cells that are very similar to those you linked. I will try to do some measurements for you a bit later if I have a chance.

And, yes, the GPA will charge 14500 cells. It will try to charge any cell you hook up to it (if you plug power into the charging port).

[Flavor]

Here are the 14500 cells with the protection board. I think you would need to do some modifications to the shell if you wanted to use them, but I think it could work.

           

Here is a shot of the 14500s without the protection board.

   

Actually, I forced it a bit, and I got the protected cells to fit. If you wanted to do some plastic shaving, I think it'd work better.

   

[carol039]

awesome thanks man. Im waiting on my pi zero to show up till i can go further with my build but I found these batteries laying around. I got a couple from some old broken wireless ps3 controllers.

   

   

I could probably fit 2 of them in the battery compartment easily. Idk what kind of performance i would get out of them though. It says its li ion 1800mAh at 3.7v. I might test it before I decide what battery layout I want to use.

[Flavor]

Those 1800mah cells look good. I will be interested to hear how they work for you. Thanks!

[carol039]

ok so now im having troubles with my batteries. I had these 1800mah cells setup and everything was working fine when i was connected to power. I even had some roms loaded up and tried em out and it worked fine. but it wouldnt stay on or turn on when disconnected from power. So i just let it charge overnight and tried it later and it still wouldnt work. So I tried a different battery it was a small quad copter battery (3.7v 700mah 35c 2.6Wh Lipo battery) . Maybe im an idiot and missed something stupid but i plugged it in and the board instantly started smoking a little. I obviously took it out and now i tried my other batteries from before and i cant get it to turn on and work. The GPA board lights turn on when its plugged in and the power button comes on instantly when i slide the power switch but the screen stays black. I also took out the rasberry pi zero and tried to test it by itself and it must have gotten fried because it wont boot at all and the zeros light wont come on at all. The GPA board seems fine and charge lights come on but idk what went wrong.

so i guess im just going to get a new pi zero and hope it works out.

[Flavor]

For it to stay on, you need a couple things.
1) The correct SD card image.
2) Hold down the ON button until the green light comes on.

It will also boot if you connect power directly to the Pi Zero, but (of course) this is not using the battery.

I have heard a few people now having problems with the pins that poke out the "back" of the battery terminals marked "H2" and "H3." In some cases, these can protrude far enough to contact the LCD casing (which is metal there) and cause problems. The best thing is to clip them off, so they do not short out against the back of the LCD.

I feel like the battery that you've shown should work fine. I guess I'd need to see how you have it connected to the GPA board to see if there's anything wrong there.

I will email you direct, so we can try to debug some things quickly.