Bought a cheap XML T6 light for the OH’s bike, stuck the charger on it for a few hours at work but wasn’t sure if it was actually charging so got it home and stuck the battery on my Smudge V1 charger, charged for a couple of hours.

Plugged the battery in to the head unit and it came on immediately and the click button on the rear did nothing. Ran the battery down and the LED in the click button changed from blue to flashing red but still powers up the light as soon as it’s connected and the tail button still does nothing.

Then realised that the charger that came with it was a 4.2V output and the Smudge one is 8.4V 😳

Battery pack is a 4×18650 with 3.7V on the side and reads 3.91V across the terminals. I’m presuming I’ve damaged something in the light unit, but what?

Oh, to add – I also plugged in the Smudge battery to the cheapy head unit to check it before realising they ran off different voltages.

Having looked at the typical drivers though, they seem to be able to handle up to 17V nominal, so it shouldn’t have really damaged anything, right?

Charging a 4V battery with 8V ain’t going to lead to happy outcome unfortunately.

Looks like the battery’s fine – just disassembled the light head and it seems I may have fried one of the FETs and a resistor on the driver PCB. Had a look on DX but they don’t seem to do one similar. Anywhere else I could look, or chalk it up to experience and buy another one?

farnell.co.uk

you could fit a Taskled Lflex to the light and as long as the led is still alive
it will work with the 4.2 volt battery pack .