NEW PRODUCT – USB/DC Lithium Polymer battery charger 5-12V – 4.2v

Mcp73861 Lrg

Mcp73861Batt Lrg

NEW PRODUCT – USB/DC Lithium Polymer battery charger 5-12V – 4.2v. Charge your single-cell lithium ion/polymer battery any which way you like with this board. Have a USB connection? No problem, just plug into the miniUSB connector. Only have a wall adapter? Any standard 2.1mm DC adapter which puts out 5 to 12VDC will work fine. If both are plugged in, the charger will automatically choose whichever has the highest voltage.

Other nice things about this charger include multiple LEDs for power & charging status, including a charging LED which will blink when the battery is full. If the charger gets too hot from high-speed charging, it will slow down the charge rate automatically. You can easily adjust the charge rate up to 1.2A or down to 100mA.

We also toss in an free JST cable!

  • Use USB or DC power – 5 to 12V input
  • Charges one single-cell Lithium ion/polymer battery at 4.2V with constant current/constant voltage
  • Three indicator LEDs – green for Power, orange for charging and red for error
  • Charging LED will blink when the battery is full
  • You don’t have to worry about heat dissipation in the charger, even when plugging in a 12V DC power jack – thermal protection inside will slow down the charge rate to prevent damage
  • 2 JST connections so you can keep the battery plugged in and powering your project
  • Terminal block connections galore (if you don’t like JST connectors) just solder in 3.5mm terminal blocks
  • Default charge rate is about 280mA, but you can easily change this by soldering in a through-hole resistor on. The chip can do 100-1200 mA charging
  • Safety timer will stop charging after about 14 hours
  • The chip supports a standard 10K thermistor, which we have stuffed as a standard resistor. You can solder in a thermistor easily
  • Lots of information in the datasheet for the MCP73861
  • Fully assembled, tested and comes with a free JST cable

Battery, USB cable and DC power plug not included. But we do stock them in the store!

The USB/DC Lithium Polymer battery charger 5-12V – 4.2v is in stock and shipping now!

Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.

Join 7,500+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython in 2018 – Python on Microcontrollers is here!

Have an amazing project to share? Join the SHOW-AND-TELL every Wednesday night at 7:30pm ET on Google+ Hangouts.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Follow Adafruit on Instagram for top secret new products, behinds the scenes and more https://www.instagram.com/adafruit/

Maker Business — Rethink Robotics closes shop. Long live collaborative robots #makerbusiness

Wearables — Zip it up

Electronics — Serial overkill

Biohacking — Biohacking Resources – Books, Talks and Podcasts

Python for Microcontrollers — CircuitPython creates new assistive tech opportunities

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !


  1. Two concerns.

    1. "12v" in the automobile is typically 13.5v or occasionally as much as 14.5. Will this blow it up? I don’t know but don’t want to try.

    2. It says 4.2v. I thought most LiPos used 3.7v. Perhaps this is just current or a typo, but I do worry without an explanation of the extra .5v.

  2. tz, according to the datasheet the max max is 13.5V. There’s a protection diode that will drop about .3V so say the absolute max is 13.8V. If you think you’ll be plugging this into a Car, solder a 1n4001 inline on the positive wire to the charger and you’ll be safe up to 14.5V

    lithium ion batteries have a nominal of 3.7v but when fully charged are 4.2v that is why you’ll see both/either numbers

  3. Just a thought for later versions…rather than “Battery In” and “Battery Out” labels, something like “Battery” and “Load” might make for easier comprehension. Maybe it’s just lack of sleep, but I spent a good two minutes staring at the photo trying to sort out why a *charging* battery was attached to “in” rather than “out.” I get it now…but still, with my little walnut-size brain that can’t remember squat…when I order one of these, first thing I’ll be doing when it arrives is tape my own labels over it so I don’t forget.

  4. Thx for the suggestion, we have a lot of PCBs made…but will consider it for the next round!

Sorry, the comment form is closed at this time.