Building a battery cable for the Arduino Nicla

The Arduino Nicla is a nice little dev board series. They have managed to cram a ton on them… but it has meant sacrificing the battery connector. Most of the dev boards from Sparkfun and Adafruit have a JST PH connector… as do most of the common LiPo batteries out. The Nicla boards however have a JST ACH. Which has 3 pins and is tiny…


Arduino put out a note on this… but it leaves a lot of the leg work up to the reader:

Here is how I built a converter cable that lets you plug normal JST PH LiPo batteries into Nicla Boards

For each cable you need:

To make the cable:

  • Cut the pre-crimped wire in half, at the middle
  • Insert the wires into the ACH Connector Housing
  • Now the tricky part is figuring out which wire goes to which pin on the JST PH connector. The diagram from the Arduino article is sort of help:
Nicla Sense ME battery connector
  • Look at the connector and orient it the same way as the diagram and note which wire should be the red wire. If you have some red tape, now is the time to use it.
  • On the JST PH connector, there is a side with a slot down the middle of it. With the slot facing up, and the connector port facing you, the Red/Positive side will be on the left. You can temporarily slide in a battery to confirm.
  • Mark which pin should be Red/Positive with a marker, if you want.
  • The next step is to strip the ends of the wires and solder them to the pins of the connector. It is a huge pain. I found it helpful to position everything and tape it down. and to swear. and buy extra parts.
  • I added a bunch of hot glue over the solder joints with the hope of providing some stress relief and also adding some strength.
  • Finally, I slide some heat shrink tubing over it all.