Here’s another battery charger designed for lithium chemistry cells, the BLU4. This charger doesn’t display much on it’s built in LCD, apart from basic cell voltage & charging current limits, as it has a built in Bluetooth module that will link into an Android or iOS app. Above the charger
Another random teardown from the junk box time! Here’s an old Motorola DECT landline phone, no use to me as I’ve not used a landline for many years. Not much on the back, other than the battery compartment for a pair of AAA rechargables. The base unit contains the charger.
I did a little more digging into the PSU circuitry of the small coin counting machine, and it’s even more strange than I thought! The part I originally thought was a transformer on the PSU board is in fact a DC-DC converter module! Here’s the device after desoldering it from