This is taken from psp-hacks dot com. I don't know how to link the pictures sorry.
Pandora's Battery: The Hardmod Method
Requirements:
- PSP
- A battery that will become a Pandora's Battery (the battery that comes with your PSP will do, but you wont be able to use the battery normally, so a new battery is reccommended)
- Memory Stick larger than 64MB
- Some sort of wedge that isn't metal to get the battery open (like a guitar pick)
- Some sort of knife to cut a very small wire
- Tape or glue
Instructions:
Making the battery
Once you have made the battery read the next section to make a Magic Memory Stick (also needed) -- Making the Magic Memory Stick
FAT BATTERY (scroll down for the Slim battery)
This is our victim --
Please note that while this concept may work on non-Sony batteries, only official batteries are guaranteed to have the same internals, so we recommend using one.
1)
The first thing you need to do is obviously crack open the battery. Surprisingly, the battery isn't very hard to get in to. In this picture --
-- you can see that this person is just using a guitar pick to slide in through an edge and slide around the perimeter of the battery to separate the two halves.
2)
Next, we need to locate a certain chip. The chip has the model number S93C56 printed on it. We are going to need to desolder pin 5 and lift it off of the board. Here is a magnified view of the board --
-- which shows where the chip is and which pin needs to be lifted.
Newer batteries have a much smaller board with a different layout. The same chip needs to have the pin lifted, but the chip is in a different position. Once you've located chip S93C56, the rest of the instructions are basically the same. This has been confirmed with the 2200 mAH Official Sony battery.
3)
If you are not confident in your soldering skills, have a less than steady hand or have a larger-than-optimal sized tip, please desolder the cell pack from the battery first. If you make contact between pins 5 and 6 then you will short ground to +3.6VDC! Not good! When desoldering the cell, only keep the iron on long enough to melt the solder. If you can, use a higher wattage iron so that the tip will be hotter, but you won't transfer as much heat to the cell pack. Remember that heat + Li-Ion battery = large explosion, so if this is your first solder job maybe you should try something easier first
Now is actually desoldering the pin. There are a few ways you could do this, but I think my method is the best because its less likely to damage components near by. Use an Xacto knife with a sharp tip and try to put it underneath the pin. Get somebody to hold a soldering iron (WITH A VERY FINE CONICAL TIP!) on the pin. When the solder melts you can pop the pin up with the knife. Be sure not to hold the iron on the board too long to avoid the lithium battery from getting too hot and exploding.
4)
Finally, close the battery's casing. Use some Krazy Glue to keep it closed, or just use electrical tape around the edges like I did. I don't actually recommend the electrical tape as it makes the battery very snug in the compartment and it takes a bit of force to get it out. You can use the battery just like a regular Pandora's battery.
How does this work?
The pin that we just lifted was actually the ground pin of the EEPROM. Removing this pin effectively shuts off the EEPROM. When the microcontroller inside the battery tries to read the EEPROM, it will think the EEPROM contains all 1s (in binary). This is because of the pull-up resistors on the data lines. So the microcontroller returns a serial number of 0xFFFFFFFF to the PSP, which then goes into service mode.
SLIM BATTERY
Apparently instead of lifting or cutting the leg of the IC04 module on the circuit board in the battery of an original psp slim battery, you can simply cut one of the traces on the board to get the same results. You can cut it with a pen knife, but don't cut completely through the board, just make sure it cuts the connection. Instant pandora battery! I may have overlooked something and before I know it my battery will send psp shrapnel into my hands. That would suck.
Trace = the cool looking connection lines that connect the components of the board together.
Also, be careful when opening your battery to not puncture the actual compnents inside since lithium can very dangerous and even explosive. It's much easier if you use something that is strong that doesn't bend easily like a glasses screwdriver or just a small screwdriver that can get into small grooves without bending. Pen knives trying to open a battery case made it difficult since the blade is flimsy and if you aren't careful, you may end up cutting yourself or punching through the soft plastic cover into the lithium cell.
I haven't done this thank goodness, but the plastic is soft enough to where this can happen. And always, never apply insane amounts of pressure no matter how mad or difficult the process can be.
THE MATERIALS
1. I'm sure you've got a small spare screwdriver somewhere.
2. The pen knife can be really cheap. I got mine for like $1.00.
PROCEDURE
1) Open the battery. I would recommend running something like a guitar pick through the crack that you create to have less chances of hurting yourself or scratching your case too much. Do not use something metal to open the battery; it could short out your battery, making it useless
2) Locate the trace to cut from this picture --
-- it's in the BLUE circle NOT THE RED -- DO NOT CUT THE PIN IN THE RED CIRCLE
3) Cut the trace using a knife
4) Put your battery back together. You can tape your battery up with tape if you don't like how it comes apart due to lack of adhesive.
TIPS
1) If you have to, dig a small hole in the cover with your screw driver between where the top and bottom covers meet, then try to run your screwdriver all the way around to break the adhesive seal.
2) The corners are tough, so if you have to, work on all four sides of the battery before trying to separate the adhesive on the corners.
3) Remember that the psp can still be powered with adapter if you manage to screw up your battery or need the psp to power up for some reason.