Fixing old solar lights

[cowsss]

Wehave some old christmas lights that stopped working. I initially thought it was the battery as they flashed on when a non-recharable AA battery was put in them, however after purchasing a new Ni-MH battery they would stay on during the day. This made me suspicous about the solar pannel, when checking it with a multimeter while my phone torch was pointed at the pannel, there was a potenial of 11mV across the pannel.

I was wondering if you guys had any advice for replacing the solar pannel in the control unit?

 

[David_AVD]

The solar panels often die from water ingress or UV clouding them over.

I guess you could try a similar sized panel from a newer set of lights?

 

[Iain]

You might be able to get similar hobby sized solar panels from Jaycar or China. Just have to be careful about the voltage. I’m guessing the original panel is regulated to a NiCad charge level, you don’t want a 12V or unregulated panel.

I find any reasonable rechargeable AA gives a much longer light, as the shop ones are usually very cheap.

 

[Notenoughlights]

How many batteries were in the unit? I've found that the ones with 3 batteries tend to have an output of 31v to the light string. I just wire a standard 31v 2 wire Christmas light power supply up to the solar strings.

 

[cowsss]

The solar panels often die from water ingress or UV clouding them over.

I guess you could try a similar sized panel from a newer set of lights?

I have got some old 5v solar pannels from another project i was hoping to do, but I don't know the voltage the original pannels would have run at. Is there any easy way to check?

 

[cowsss]

You might be able to get similar hobby sized solar panels from Jaycar or China. Just have to be careful about the voltage. I’m guessing the original panel is regulated to a NiCad charge level, you don’t want a 12V or unregulated panel.

I find any reasonable rechargeable AA gives a much longer light, as the shop ones are usually very cheap.

there is one 1.2v Ni-MH cell. But there is quite a bit of circutry between the two, I will have a closer look at the chips on there to see if any of them give any infomation as to an expected input voltage