Battery Power

AcidRainLiTE · Post by **AcidRainLiTE** » Sat Jan 07, 2006 9:39 pm

I am trying to run the psone and lcd on 6 AA NiMH 2500mAh batteries. The lcd has the led mod (6 leds). The playstation boots up and works but the screen is wavy. I don't understand why. When I run it with the AC adaptor and measure the current draw it doesn't go over 1.3A and is usually 1A or less. The batteries are supposed to be able to provide 2.5A for 1 hour right? They were charged right before I tried them.

Thanks.

Weebl · Post by **Weebl** » Sat Jan 07, 2006 10:57 pm

What kind of charger are you using? If its a quick charger (2 hr. or something similar), it might not be charging them to their full potential. At least, in my experience with NiMH batteries that has been the problem for me. The best way to get duration out of batteries is to use a Radioshack 11 hr. charger.

AcidRainLiTE · Post by **AcidRainLiTE** » Sat Jan 07, 2006 11:44 pm

Yeah that might be the problem, its a 15 min charger. I will see if i can get a hold of a different charger. Thanks.

timmeh87 · Post by **timmeh87** » Mon Jan 09, 2006 5:44 pm

1) quick chargers typically charge batteries to 70% of their rated capacity in the first 15 minutes. i dont know how they work exactly, but id assume you need to leave the batterys on for a few hours to get 100% capacity into them.

2) just because a battery is rated for 2300 mAh, it does not mean that it can provide a current of 2.3A for an hour. It dosent mean it can't either. rated capacity and maximum current draw are completely separate things

3) your problem is not with a lack of power coming off the batteries. in fact, nimh batteries should preform about the same whether there is 90% 60% or 30% left in them - they have a very flat discharge curve, and charge state has little influence on maximum current.

my brother had similar problems with the LED mod on the psone screen. it is related to the fact that the LED mod draws a different amount of current from a different place on the board than was originally in the design. its not a fun thing to try to troubleshoot. he ended up fixing it by adding some capacitors to the audio daughterbaord. the thread is from about a week ago in the portable screen forum. he posted some pictures, you should go see if youre getting the same thing.

AcidRainLiTE · Post by **AcidRainLiTE** » Sat Jan 14, 2006 5:01 pm

I dont think the led's are causing the problem: I disconnected the leds from the lcd circuit power and wired them to a seperate set of batteries and ran the psone and lcd on another set. It still doesn't work (actually it doesnt even finish booting now, it trys, starts playing the playstation boot up sound, then cuts off and starts again). Any other ideas? Thanks.

AcidRainLiTE · Post by **AcidRainLiTE** » Sat Jan 14, 2006 8:19 pm

Actually it might be the led mod that is causing the problem. I added another battery to get 8.4V and it boots farther then it does with 7.2V. If I remember correctly the led's I got were 3.5V so maybe the overall setup isn't drawing as much voltage which would result in it not drawing as much current (or maybe its not drawing enough current witch lowers voltage draw?) Does that sound possible?

AcidRainLiTE · Post by **AcidRainLiTE** » Sun Jan 15, 2006 3:42 pm

timmeh87: is this the thread you were referring to? http://benheck.com/phpBB/viewtopic.php?t=8402 If it is, I am not really having the same problem. I don't have inversion of colors and it works perfectly fine with the ac adaptor. It just doesn't seem to be getting enough power to boot when run on batteries.

I measured the voltage draw when it is run off of batteries and it is only about 6.3V. So for some reason it either isn't drawing enough power or the batteries are not supplying enough power. Anyone have any suggestions? Is there a way I can force voltage or something?

CJWJ · Post by **CJWJ** » Tue Jan 17, 2006 4:48 pm

AcidRainLiTE wrote:I measured the voltage draw when it is run off of batteries and it is only about 6.3V. So for some reason it either isn't drawing enough power or the batteries are not supplying enough power. Anyone have any suggestions? Is there a way I can force voltage or something?

Hi Acid,

I also had this problem. Make sure you have plenty of juice in your batteries, ea let them on the charger at least an hour after the led (on charger) for trickle charging pops on (if this led exists).

If it still has wavy display, try hooking up more AA batteries.
It's OK to let the voltage rise above 8 volts, BUT (this is important) measure the output voltage of the batterypack (NOT connected to the portable or something else). If it it above 7.8 (*cough* eight) volts add an 1N4001 Diode to drop the voltage 0.6 volts down. If the voltage is still too high, add another 1N4001 Diode.

like this:
(i hope this ascii-matic works out)

Code: Select all

 ________|\|______o Battery voltage minus 0.6V OUT (in this case 9.4 V)
 |       |/|
 |
 n  10V (POSITIVE)
---
| |
| |
| |
--- 0V (GND)
 |_______________o GND OUT (doesn't change)

You can thus get away with using a 9.6 V batterypack, or other non-ps-compatible voltages. Take care to use 1N400X diodes. If these are not available, ask for high current rectifier diodes.

I got away with using 13.8 V slimline batt-packs for use in portable DVD-players (the cheapo ones). These pack quite a charge.

Greets, Jaco Sloof