Similar to my GBA SP battery cover mod, this is a battery cover mod for the DS Lite. It uses the exact same battery and the install and print instructions are the exact same (hence the copy/paste). Unlike the GBA SP, the DS Lite is better suited for this size and shape battery so the cover protrusion is significantly smaller.
I tweaked the original cover from Coffea but I expanded it to hide a 2Ah turnigy battery from hobbyking.
This is the only extra part I used:
Warning: Completing this mod requires irreversible modification to the DS Lite. You have to permanently remove portions of the lower housing to fit the battery snugly. I recommend using an aftermarket housing. Soldering is REQUIRED.
You have to remove a large section of the internal battery tray on the lower housing near the cartridge connector. After making physical room for the battery, I removed the battery connector from the motherboard and the JST connector from the battery and soldered the battery to the bare pads. Using a connector would be optimal but I have not yet found one that will fit properly and is skookum enough. I used hot glue on the soldered terminals to secure the wires. You can solder directly to the battery connector on the DSL without removing it, but I opted to remove it since it will give me a little bit more room to work with and it will make the mod reversible as long as I replace the lower housing and do not lose the desoldered connector. Until final assembly, the battery should always remain disconnected from the circuit board to protect from shorts.
Do mind the spring for the shoulder button. Without the internal battery compartment, the little pointy metal bit is free to stick into your finger or the battery and ruin your day. Don't say I didn't warn you.
This should be printable with any material and it should be sized appropriately. I'd recommend transparent PETG, but this will work fine in whatever color or in PLA and tolerances should be loose enough that any smallish nozzle size and layer height would be fine. I printed this both with .3 and .4 mm nozzle with no issues and at both .1 and .15 mm layer height.