[Mark B] had a problem. He’d come into possession of an Acer N30 PDA, sans batteries. He couldn’t just throw any old cells in, since the unit expected to communicate with an onboard controller chip in the original pack. What ensued was his effort to emulate the original battery controller hardware. This is classic Hackaday right here, folks.

Just wiring in typical Li-Ion voltages to the PDAs battery pins wasn’t enough to make this Windows CE device happy. The device kept fleeing to sleep mode, thinking the battery was faulty or very low. Eventually, inspecting the motherboard revealed the PDA hosted a BQ24025 charger IC from Texas Instruments. [Mark] surmised it was trying to communciate with a BQ26500 “gas gauge” IC from the original battery pack. Armed with that knowledge, he then set about programming an STM32 chip to emulate its behavior. He then successfully ported the functionality over to a CH32V003 microcontroller as well. Paired with a Nokia BL-5CT battery, he had a working portable power solution for his PDA.

It’s great to see ancient hardware brought back to functionality with some good old fashioned hacking. I’d hoped to do the same with my Apple Newton before someone nicked it from my lounge room, more’s the pity. If you’re rescuing your own beleaguered battery-powered portables, don’t hesitate to let us know!