The our ancient flir r440 identifier gamma spectrometer at our 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 it 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 18650’s, but it turns out you can just buy the fey LNB46E packs and its plug and play.

To get the protection stack back in you may need to pop off the weird circular connector pcb from the housing with a 24mm socket to mate the connector with the protection circuit before sliding it back in.

Then it’s just to slide the assembly back in and you can glue it back in place

Now we got a fully functional r440 again in the lab