Technology Casserole

A few weeks ago, the seasonal solar lighting merchandise showed up at the IKEA store here in Orlando. It’s all priced quite well for outdoor solar-powered gear so I went and picked up a few things to play with. I then promptly disassembled my new lights and here is what I found.

This is the inside of the power module for the 3 uplight kit. (It’s the same module and batteries that are found in the 8 globe light chain – I got one of those from the as-is section last weekend.)

Four screws later and you can see the two 1000mAh NiMH batteries that are mentioned on the package, presumably that’s all the panel could charge in one day since that’s very little capacity for a AA rechargeable. It will run the 3 banks of 3 LED’s all night if they fully charge, however. The standard size battery means they can easily be replaced after daily charging cycles deplete the capacity.

The problem is, when they are mostly-discharged the lights will start to flash on and off as the battery circuit loads and unloads. Depending on how well the LED driver is designed that could greatly shorten their lifespan. A low-voltage cutoff or adding a small amount of hysteresis through current feedback should prevent this and I plan to experiment on my light chain’s power module to see if there is a simple solution.

In the interim I am quite happy with my lights, and so are the palm trees. I am trying to find an excuse to get some of the totally self-contained dome-shaped units as well – I just need somewhere to put them…

Thanks to the article on IKEAfans for piquing my interest.