Battery Power for LED Pixels and Strips

by Phillip Burgess

published July 29, 2012, last updated July 29, 2012

posted in LEDs

Save Download

Beginner

Project guide

Diode Fix for Alkaline Batteries

“I don’t know if you wanna trust the safety of our country to some, uh…silicone diode!”

— General Beringer, WarGames

A single 1N4001 diode has about a 0.7 Volt drop across its leads. Wired to our 6 Volt battery pack (when using alkaline cells), this yields 5.3 Volts output. That’s within our 5V±10% target window, so this simple component addition is all that’s needed to use the battery pack with the LED strips and pixels.

This same solution can be seen in our Digital Programmable LED Belt Kit.

Diodes have a specific polarity, passing current in only one direction…the silver stripe is the + end. So we want to connect the + terminal from the battery pack to the “dark” end with no stripe.

This sequence is only needed if you’ll be using alkaline cells. If you know for a FACT that ONLY rechargeables will be used, this part can be skipped. If you’re unsure, or will use different cells at different times, add the diode.

This works for small projects with a short run of LEDs; at most about 1A average current. A single small diode like this is not rated for the high current required of larger projects.

Cut the red wire of the battery pack short by about an inch.

Strip off about 3/8" insulation from the red wire.

Then “tin” the end of the wire with a bit of solder to keep it from fraying.

Clip the end of the diode (the “dark” end, without a silver stripe) to a similar length, then solder the red wire to this.

Clip the other end of the diode (the side with a silver stripe).

Cut off and slide a 2" piece of heat shrink tube onto the red wire. Keep sliding it all the way past the diode.

Now solder the positive wire from your LED circuit to the “stripe” end of the diode. Or you can add a plug/receptacle pair between the two to make them easier to separate and service later on.

Take the piece of heat shrink you slid over the wire before…

…and slide it back over the diode and the solder joints.

Shrink the tubing to grip the diode and wires. You can use a heat gun, lighter or the edge of your soldering iron.

Taa-daah!

The black wire from the battery holder then connects to the ground wire of the LED circuit (or plug/receptacle, if you’ve installed one). This side is much simpler than the diode-equipped wire: