Tools:

EBL 18650 3.7V 3000mAh Li-ion Rechargeable Batteries
https://amzn.to/2HoFW5B

Charger
https://amzn.to/2JD1AUG

Holders
https://amzn.to/2JzFF0t

Transcript:

It’s time for another Cool Tool review. This time we’re taking a look at the most popular rechargeable battery most people know nothing about. This is the 18650, I got a pair of these name brand ones for $9, though you can get sketchy ones even cheaper. I’m going to show you why they’re useful and if you want some for yourself, using the Amazon link in the description helps support my videos and the Cool Tools blog.

The 18650 battery is an extremely common, Lithium Ion rechargeable battery. We just don’t normally see them because they’re tucked away inside our electronics. I opened up a rechargeable drill recently and found one inside. There’s one inside this solar emergency radio I own. I’m sure there are a handful of others in my house I’m not even aware of.

They’re relatively cheap, easy to recharge, and they can store a lot of power compared to rechargeable AA battery.

What makes these great for electronic projects and cosplay lighting effects is that they spit out a 3.7 volts that’s perfect for small project boards like the Teensy, Adafruit Trinket, Gemma, Feather. And it turns out to also be a good enough voltage for driving LED strip.

So for example, I wanted to put some LEDs on my Power Racer to show it off at night. I glued in some strip, and wired it up to Gemma board. And to power it, I first used one of these flat Li-Po packs, but it didn’t hold much charge, and when it runs out I either had to recharge it through the board over USB, or swap it out by pulling this tiny connection. It wasn’t worth it.

As an alternative, I also tried running it off AA batteries, which were easier to swap out, but drained just as fast.

So far, using a single 18650 has worked the best. I bought a 10-pack of these holders on Amazon for around $7, wired one up and glued it in. With this, it runs for longer than I need, and a loop of gaffer tape around it makes it easy to pull out when I need to recharge.

You do need to get a special charger. This one with a nice LCD display cost me $16 on Amazon. It runs off USB. You can get cheaper ones without the screen.

So that’s my story with 18650 rechargeable batteries. They’re great for powering small project boards and LEDs, which are honestly the bread and butter of most maker projects.

Like any rechargeable battery though, you have to be careful not to puncture it or expose it to fire, so be careful.

You can pick up the batteries, the holders, and the charger all using the Amazon links in the description, and remember can see thousands of reader recommended tools like these at Cool-Tools.org.

Find more Cool Tool reviews here:
http://kk.org/cooltools