Battery shell for Keysight U5850 series thermal imager by Kilrah

Last crawled date: 3 years ago

A few of us have managed to snatch heavily discounted Keysight U5855A thermal imagers from a Keysight eBay clearance sale, but most of the units came completely bare.
Seeing as the battery sells for >$100 it became a bit of a challenge to find a homebrew solution.
See this thread for details and background:http://www.eevblog.com/forum/thermal-imaging/keysight-u5855a-trueir-thermal-imager/
The case fits the 2x18650 cells and should have enough room to house a 2s BMS on top (important, since the camera drains the battery when off so if one forgets to remove it between uses it would cause a deep discharge).
I used tinned desoldering braid for the contacts. For the camera to charge the battery a 6.8k resistor is required between the Sense pin and positve, and a 10k one between the Temp pin and negative (originally a thermistor), see picture for polarity. I installed the resistors on the camera but added (untested) recesses to the case if someone wants to "do it right" and put them in the battery.
I used this BMS: https://fr.aliexpress.com/item/2S-4A-Li-ion-8-4V-18650-DIY-BMS-PCM-battery-protection-board-bms-pcm-for/32398042035.html?spm=2114.13010608.0.0.4vlzB6