I bought an LED light a couple of years ago, it came with a battery that was 2 x 18650 2200mah cells, in series, in a waterproof cover. I've used it on my commute ever since.
A few weeks ago the light went out and wouldn't come back on.
I did some basic checks with my DVM and found the battery was giving no power at the connector. I removed the water proof cover and checked the individual cells and they were fine - fully charged. I decided that the PCB that 'manages' the batteries had gone wrong somehow.
Sooooo I bought some new 18650 cells (3000mah) and a battery holder with a built in PCB. Soldered the original connector onto the leads of the battery holder, charged the batteries, fitted it all together and expected it to just work.
It didn't work and I don't understand why - because I don't really understand the needs of LED lights I guess.
Can anyone advise where I went wrong? Any experts who would be prepared to help??