Off Grid Home Forums Technical Discussion Energy saving light bulbs Re: Energy saving light bulbs


One of my clients bemoaned the fact he was unable to find 12V LED lighting only battery operated ones using 3 or 4 dry cells. And he didn’t want to buy a car adaptor costing $60 or more.

Good quality LED lights do have an internal regulator ccircuit to convert the raw 12V DC power so it really isn’t less efficient to use external adaptors instead of dropping resistors that just waste the power. Switch mode supplies typically run at better than 90% efficiency when fully loaded. How much does a dropping resistor waste by comparison. The answer being more! and it produces heat in the process. Not so good in warm climates.

I realized many of the cell phone power adaptors are really switch mode regulators and these often end up in the dumpster when people upgrade to a new cell phone.

What it means is you can take one of these junked car adaptors that charges the 4.5V cell phone battery packs and feed it from your RV raw 12 V and regulates it down to feed LED portable lamps intended for battery operation. It seems most manufacturers make adaptors with incompatible plug/socket connectors so the old never seems to fit the new.