What is it?

There are other micro lipo charging circuits out there. But sometimes even those are still too large for your jewelry or gadget project. And even if they do fit, does those Micro Lipo Chargers have a built in On/Off switch? Probably Not! This is the smallest Micro USB Lipo (Lithium Polymer) battery charger circuit board on the market that also has a tiny On/Off switch! It uses the same battle tested charging controller chip used in the micro charger sold by Sparkfun along with a status LED. However ours is less than half the size!

Why did you make it?

We were designing a set of sunglasses with an LED strip and running on a tiny Arduino Trinket. However, due to space limitations we had less than a postage stamp area above the 150 mAh battery pack to cram a charging circuit board with micro usb connector and a tiny On/Off switch. We couldn't find anything on the market that would fit our requirements without being heavily modified (i.e. non-essential portion of board chopped off! and painstakingly trying to solder into spots that weren't designed to be soldered into). So we finally resorted to designing our own charging circuit board that could fit in such a tiny space. Voila! The Nano Lipo Charger was born!

What makes it special?

It is the tiniest Micro USB Lipo Charger in the market (It physically would not be possible to make it any smaller than we have made this little guy!) The Nano Lipo Charger measures 16.3 mm wide x 9.2 mm high x 4.2mm thick (at the usb connector). To get it's footprint to be so small we had to make it a 4 layer circuit board. It's smaller than a penny and can basically fit anywhere! Put it into any project where space and weight are of high importance. It has a voltage range of 3.7v to 4.2v and a 500mAh charge rate. It can charge a 3.7v-150mAh Lipo battery in under 30 min and a 3.7v-500mAh Lipo battery in about 90 min. So it is also fast! The back has been silk screen printed to indicate the (+) and (-) terminals and which terminals are for the battery (Bat). You may need a magnifying glass to hook this one up, but if maximum tininess is important to you... than the Nano Lipo Charger is the charging circuit board you've been looking hard for!