Got Rovus BR-33B6 cordless vacuum as giveaway. Wanted to use it for casual computer cleaning. Then noticed that fully charged thing works only 15 seconds and then gradually fizzle out in next 20-30 seconds. Charging was painfully slow and happened only in switched off position. After few charging cycles decided to gut it out to see what is inside. Sorry, forgot about making "vanilla" photo and threw out battery before stumbled upon subject. AAA size 7.2V 1200 mAh NiMH "green" battery array, spot-welded together in series and tucked in gap around motor. Motor - most likely Chinese RS365. Drawed a circuit of this PCB in Kicad - had a reason to learn Kicad at last. See attached PDF.

As expected - switching NiMH battery between charger and DC motor. I'm curious about which charging control IC Chinese "ingenious" mind used here. From function here it is more like a simple NE555 timer used to blink blue LED in 1 second interval. But pinout is different.
Nothing to fix in vanilla state. Simply "improved" existing design by soldering out redundant components and connecting motor and switch directly to power connector on PCB. Only LED indicator remained to indicate working state. Test with lab PSU clearly stated that original battery was... erm... a little too weak for prolonged cleaning


So next task is to find suitable and handy enough PSU for this thing for cheap.
Rovus_BR-33B6.pdf (30.46 kB - downloaded 239 times.)