I just modded my psp with 2 cell phone batteries, 3.6 volt 900mah each. I wired them like this:
The two cell phone batteries in the umd area (umd drive taken out) and then i have my regular psp battery, the 1800 mah one. Heres the problem I guess, when i load up my psp it takes the power from the cell phone battery ( ive only tested it so far with one battery plugged in) and then when i unplug the cell battery it reverts back to the psp one.
I can see it does that because i have a battery hud plugin on my xmb and it tells me the battery remaining time, it goes from 9 hours on reg battery to about 3 hours when i have the cell phone battery plugged in. Now i though i had them running parrallel, but I didnt do anything to the psp battery. I soldered the wires to the cell batteries here:
So to summarize: 2 cell phone batteries and psp battery. When cell batteries are plugged in the psp only uses them, then when i take them out it reverts back to psp battery. Now if i can't do anything from here, Should i just put a switch for the cell batteries to take over when my psp battery goes low? and with my cell batteries still charge?