I first got the idea when making the Solar PSP charger from Yo Chuck's Instructable.(https://www.instructables.com/id/Solar_Rechargeable_Battery_Powered_PSP_Charger/ ).My Battery pack or solar cell did not fit in the altoids can very well so I decided I would make my own off of the idea. Yo chucks is more portable as it will easily fit in your pocket, but this will provide more charge time and being able to charge your batteries and the PSP at the same time.

Step 1: Getting Your Materials

First, obviously, you will need all your materials. It is much easier to make your charger, as well as possibly improving on the idea yourself, if you have everything you need laid out in front of you.
You can get most if not all of what you need at Radioshack or comparable electronics stores.

You will need:
(1x) Medium sized project box (Catalog #:270-1806)
(2x) Battery Packs(without on/off switch) (Catalog #: 270-391)
(2x) DPDT mini-switch (Catalog #: 275-626) Make sure this is an ON-Off-ON
(1x) Solar Cell(6v 50 mAH)(Catalog #: 277-1205) This part is more expensive, if you have smaller ones, put them together to get about the same, the higher the amps the faster the batteries will charge but do not go too high obviously.
(1x) LED. This part you can get by itself, in a multi-pack, or with a built in resistor. I used one with a built in resistor to simplify the wiring. If you do, do not put the resistor showed in the diagram into the wiring) (Catalog #: 276-270)
(1x) 150 Ohm Resistor. You ONLY NEED THIS if you do not get an LED with a built in resistor.
(1x) Rectifying Diode(the smallest they have will do fine)
(1x) PSP Charger. If you have an extra use it, if not you can pick one up pretty cheap.
(8x) Rechargable AA batteries.

You will also need the following tools:
Wire... A few feet will be fine, this is just to make your connections with the existing wires.
Solder
Soldering Iron
HeatShrink(not needed but I used for good measure)
Hot Glue Gun w/ Hot glue.
Drill with bits(1/4 inch bit)

Step 2: Laying It Out

Alright, now that you have everything, start planning. I will tell you how I put everything in. If you see a better placement, then go for it! Try to "dry fit" the battery packs and make sure you will have room. A dremel will be good for modifying the box a little bit. I had to cut a little bit of the plastic from the inside that was left over from the molding process when they made it. Look at the box and see where you want to put the switches and LED. I would recommend putting the LED as close to the switch with the PSP charger so to avoid confusion for which switch does what. Go ahead and place the solar cell on the lid and mark where you will need to cut, keeping in mind you need to cut the hole smaller than the cell so it will have a place to sit and to be glued. You can also just glue the cell to the top of the lid and drill a little hole to run the wires into the box.

Step 3: Put It Together!

In this step we will be putting it together. Decide what you are going to do with the lid. I cut a hole in the lid to put the solar cell in. If you decide to do that mark your lines about a quarter inch in from the ends of the cell, and an 1/8th inch on the sides, and cut it out. Hot glue the cell to the underside of the lid. If you decide to glue the cell to the top of the lid mark where you want to put it and drill a hole to run the wires. Put them in the hole and glue the cell to the lid. Now Lay it aside and get ready for the fun!!!

Step 4: Wiring the Whole Thing.

This is where all the fun is. Following the wiring diagram, wire everything up. If you decide to use heat shrink to protect the connections from touching be sure to cut to length(usually 1/2" pieces will do) and slide them on the wires before soldering. Then slide up over connection and heat it up. It is very important before wiring to make sure you have enough wire to reach everything. It is better to have too much than too little, you can always tuck away an inch or two of extra wire.

Step 5: Put It All Together

After you have all wiring done, now is time to put everything back in the box. I recommend starting with the battery packs, put them in and hot glue them to the bottom of the box, running the wires to the side you will be mounting the switches. You might find it helpful to glue the wires to the sides at the bottom to keep it clean. Next mount the switches and LED where you want them. Again, might be helpful to glue wires to keep it clean. Also, I made sure that both switches when switched to the same side, corresponded with the same battery pack. This just makes it easier to keep track of what pack is charged or charging. Once everything is secure, look it over and pat yourself on the back.

Step 6: Test It Out.

I put one set of charged batteries in one pack, and dead batteries in the second pack. This way I could test and make sure the PSP was charging properly and with the other set check that the batteries are charging. You can set it to charge the PSP with one set while charging the second pack. Make sure to not try charging a battery pack while simultaneously charge the PSP with the same pack. Doing that will raise it to 12 volts and will harm your PSP battery and possibly the PSP itself. It is not my problem if you decide to do this and kill your PSP.