Vape Battery Replacement for 3x AAA Holder

Disposable vapes create a lot of waste. If you look it won't take you long to find them lying beside the road. Inside each is a perfectly good, rechargable Li-ion cell.

This is a simple project that will allow you to reuse these cells.

• 3D printer (Files here and on Thingiverse)
• Soldering iron
• Pliers
• Hot glue gun

Other helpful but not necessary tools:

• Multimeter
• Helping hands
• Tin snips
• Dremel/wire brush
• Vice

Materials :

• Wires (can be from the salvaged vape)
• Strips of metal (tin can lid)
• Battery pack +ve and -ve (spring) ends (Can be from the 3xAAA module)
• Solder
• 3D printer filament
• Hot glue

First check that your torch has the right sort of battery holder. This project will replace a holder that takes 3 AAA batteries packages so that there is a flat contact on either end, positive opposite from negative.

3 rechargable AAA batteries have a nominal combined voltage of 3.6 vs 3.7 volts for a Li-ion cell, this makes it perfect for a straight swap (at full charge a Li-ion will be up to 4.2 v, well under the 4.5 volts of 3 non-rechargable AAAs so still safe).

Next find some old vapes. You can pull the batteries out with pliers and carfully cut them free. Some disposable vapes have a USB connector and charging circutry (chunky purple one at the top) - save this for the battery charger!

Print the cell holder. Find some bits of metal to use as the contacts. Use whatever works, simple naked wire would work. I cut strips from the lid of a metal can (I used dremel with wire brush to sand off the plastic coating).

Solder the battery onto the contacts.

Wedge the battery so it doesn't rattle around. Most vapes have a small piece of EVA foam you could use. Hot glue also works.

Test it in your torch!

Print the charger.

Get your USB charging board. You can use one from a vape or get a new one. Hobby stores sell them. I'm in New Zealand, Jaycar sells them for less than $10, Ali Express sells them for about $0.70.

Use the battery pack +ve and -ve connections. Use the spring on the flat side of the charger, use the domed one on the keyed side. This is important as it will stop the cell making connection if you plug the battery in the wrong way round. Cheap charging boards do not have reverse polarity protection, it will discharge through the charger and could start a fire!

Attach wires to the charging board. If you are using an old vape board use the wires that connected it to the battery. They should be color coded. Feed the wires through the end holes and solder to the connectors.

Hot glue the connectors to the charger. Hot glue the USB board to the side.

Before charging, make sure the orientation of the Li-ion cell matches the polarity of the charger. Make sure you are consistent with the orientation of the cells.

The first time you charge the cell, do it in a safe place and monitor it closely in case something has been reversed.