Replacing T5 in Solar Charging Light

[james2k2]

Hi All,

After seeing Dave's eev video on replacing his bathroom T4 with LED strips, I had a thought about a solar charged light I have where it uses one of those little T5 tubes and unfortunately was quite poor in actual light output - even with a new tube, so I want to replace the tube with LED's. Not a problem I thought! Remove the starter electronics and take a direct feed with some voltage dropping for the white LED's.

I *think* the solar panel has died. I can't get a voltage at all from the DC plug on it and I can't open up the panel without damaging it as it's a fully enclosed waterproof one designed to go on an outdoor wall or shed roof as it's original purpose was an emergency light.

Can anybody give me any pointers on testing small solar panels like these? If it helps, I think the reverse protection diode has failed as instead of infinite reverse resistance, it has somewhere in the realms of 500K and then around 6K forward. Hmm.

So, if I want to go ahead with this project, I guess the first thing would be to replace that diode. Then the panel if required. As for charging, at the moment the PCB simply links the solar panel output directly to the battery terminals - what cheap improvements could be made here?

You're all probably thinking "Why would he continue with this if it's this far gone?" I like the chassis of the thing as a whole. It has mounting holes on the back and is big enough to fit extra stuff in if required and I like the diffuser too. The thing as a whole only cost me £5 so it's worth it just keeping the casing.