We’ve been exploring different options for DC 24V lighting in the house using solar panels to charge a set of 4x 6V lead acid golf cart batteries. Our previous LED light tests worked but the light was a cool white which I’ve never liked for home lighting. Also, the previous test used 0.5W LEDs which would require alot to light a house. Yesterday we received a pack of 7W warm white LEDs we ordered off of eBay.

They cost about 35 THB each (1 USD).

We figured that 7W was a lot of power for such a small package so we added a small heatsink for testing.

The batteries were charged to 25.1V:

Here are a few pictures (at different exposures) of it powered on with no current limiting at 25.1V:

It does look like a nice warm white color. At 25.1V, it appears to draw about 0.37A. This comes out to about 9.3W, which is over spec by about 30%. So we’ll need to add a power transistor in series to do current limiting.

The lighting won’t just be helpful once we move in. DC battery/solar powered lighting is quite helpful as we work on the AC electrical wiring and other construction after dark, which happens quite often. (I’m going by after work almost every day.)

I’m going to try and get a few of these wired up in the house and see how it looks at night.