About this replacement
Fluke TiR32 / TiR29 / 4JNW4 Series — 7.4V Li-ion Replacement Battery (TI-SBP3)
This 7.4V 3200mAh Li-ion pack replaces OEM part TI-SBP3 in Fluke thermal imaging cameras including the 4JNW4, 4JNW5, TiR29, and TiR32. It fits the same battery bay and uses the same connector and BMS handshake as the original. Capacity matches the product data: 3200mAh / 23.68Wh.
- TiR29, TiR32, 4JNW4, 4JNW5 platform fit: These models share a common battery bay, 7.4V nominal rail, and BMS communication protocol. The pack slot, locking tab geometry, and contact alignment are identical across this camera family, so one SKU covers the group without adapter or modification.
- Bench tested on actual hardware: We ran this pack through power-on, IR detector initialisation, and sustained imaging load on a TiR32 body. The BMS held regulation during detector warm-up — the highest-draw phase — and the camera's battery indicator tracked state-of-charge correctly across a full discharge cycle.
- First-deployment calibration: After installing a fresh pack, run a full calibration cycle through the camera's instrument menu before heading into the field. The camera maps battery state during that calibration pass — skip it and the low-battery warning triggers early on your first measurement session.
Why the TiR32 shuts down at the moment the IR detector initialises
The IR detector in these Fluke cameras draws a short, sharp current spike during the detector cool-down and initialisation phase immediately after power-on. A battery with aged or stressed cells can't sustain that spike without the cell voltage sagging below the BMS cutoff threshold — typically around 6.0V under load. The camera interprets the voltage drop as a depleted pack and cuts power before the live image even appears. Replacing the pack resolves this when cell internal resistance has climbed; a fresh cell holds voltage under the initialisation surge.
Pack shows full charge but camera dies mid-thermal survey
This happens when a pack has been through many shallow cycles — partial charges and discharges — without a full cycle to reset the camera's charge tracking. The displayed percentage drifts high because the camera's state-of-charge estimate was never re-anchored to actual cell capacity. The fix is to run the new pack down to the camera's automatic low-battery shutdown, then charge it uninterrupted to 100% before the next session. After one complete cycle, the indicator reads accurately and the mid-survey shutdowns stop.