Our ancient Flir R440 identifier gamma spectrometer at the lab uses some weird custom batteries with a circular pattern connector.

As the instrument is nearing 10 years of age, the batteries were pretty much dead. After some requests to our supplier, it turns out you couldn’t order new ones, so I popped one open.

To get the cells apart, you just have to dig out some glue on the front panel (top and bottom where the USB connector is), and you can pull out the entire USB charging circuit with a protected 2x 3350 mAh 18650 cell. You don’t have to pull off the sticker like I did to do this.

We could probably have saved some money by just replacing the 18650s, but it turns out you can buy the Fey LNB46E packs and they are plug and play.

To get the protection stack back in, you may need to pop the weird circular connector PCB out of the housing with a 24 mm socket. This lets you mate the connector with the protection circuit before sliding it back in.

Then it’s just a matter of sliding the assembly back in and gluing it in place.

Now we have a fully functional R440 again in the lab.