Reply To: Changing LED power source from battery to USB powerbank

[blinky465 17028xp 0]

Are they controllable? There’s more circuitry in there than I’d have expected for a couple of LEDs! Just a complete shot in the dark, but since your batteries are going to drain from a combined, roughly 4.6V (from fully charged) down to around 3.6V or less as they deplete it’s possible there’s a constant voltage circuit on there (and then instead of applying the full voltage to all LEDs at once, some kind of multiplexing going on). The surface mount push button looks in a funny place – do you press the plastic case of these lights to turn them on/off?

Anyway, all that aside, I’d be tempted to just stick a wire onto each of the BT+ and BT- terminals (it’s a pretty good guess that’s BT for battery and +/- for the positive and negative terminals). If you can, try tracing these to the back where the battery pack is, and double-check that the -ve terminal goes to the “first spring” (see earlier images) and the +ve terminal goes to the “last battery head connector”. I’m almost certain they will.

There’s no way those six LEDs (I’m assuming three white and three “warm white”?) will pull 3A. Those three labelled D1/2/3 may be diodes and you’ve only three LEDs (in which case, current draw will be tiny) but they look all the world like “warm white” LEDs to me?

You might get away with a 10A supply but given the difference in price is only a few pounds/euros, it wouldn’t hurt to use a 20A power supply if you can get hold of one. Simply put wires onto the B+ and B- terminals, wire all the + and all the – together, ram them into the 5V out of your mains-to-5VDC power supply.

Ta-da! No more eating batteries.