Battery to Mains coversion.

Welsh_Rarebit

My wife has 15 battery powered colour changing candles.

That makes 45 AAA batteries to change every couple of weeks.

Rechargeable batteries last a lot less so I wondered if anyone had any great ideas to convert a device that takes 3 AAA batteries to a mains connected device?

Ditto for 6 candles that each take 2 x AA batteries.

matelodave

3 AA batteries is around 4.5 volts, which is a bit less than the 5 volts from a USB phone charger, so it wouldn't be difficult to rake out an old phone charger - I must have half a dozen kicking around the house - or they aren't expensive to buy new (try the pound shop) and cut the phone end off and connect it to the battery terminals (make sure you connect + to + and - to minus). You could fit a usb socket to the candle and make it pluggable.

You could the same with the 2xAA battery units, but you'd need to put a resistor in series the drop some of the voltage, use this calculator to do the sums for you. In fact by using the calculator you could find the resistance required to drop the voltage from any plug-in power unit that you might have lying around. You can buy them from Maplins

molerat

You can buy mains to multi AA / AAA adaptors but they are not cheap, I have also seen mains to 3 x 3 AAA adaptors. There are many guides on line how to make your own using dowel rod and drawing pins. Commercial set ups are available, my garden centre had one at Christmas running many decorations from one power supply.
https://www.youtube.com/watch?v=Vl0r2psFGlU

Jackmydad

Sounds like a load of bother having adaptors to me.
What rechargeable batteries are you using? I was using some decent NimH ones to power the LED lights on a little Christmas tree. They seemed to last quite well.

ajbell

Go to your local hardware store and ask for four candles.