Steinel MobileHEAT 3 18V Replacement Battery 6000mAh

Steinel MobileHEAT 3 / GluePRO 18V — 18V Li-ion Replacement Battery

This 18V 6000mAh Li-ion battery fits the Steinel MobileHEAT 3, GluePRO 18V, and MH3 cordless heat tools. It replaces the original pack on tools used for shrink-wrapping, paint removal, and thermal soldering tasks. Capacity is 6000mAh (108Wh) — taken directly from the product specification, not extrapolated.

• MobileHEAT 3 and GluePRO 18V platform fit: Both tools share the same 18V battery interface and connector pinout. The BMS handshake voltage and communication protocol are identical across this platform, so one pack covers both tools without modification.
• Bench tested on actual hardware: We ran this pack through sustained high-draw cycles simulating heat-element load. The BMS held the discharge rail steady and triggered thermal protection at the correct threshold — no premature cutoff during continuous draw.
• Heat-element cycling on first use: On first use, run the heat gun at a low temperature setting for two full cycles before switching to maximum output. This gives the BMS time to profile the heat element's sustained current draw before setting its overcurrent protection thresholds accurately.

Thermal cutoff under sustained MobileHEAT 3 maximum-output load

The MobileHEAT 3 heat element draws heavy sustained current at maximum temperature settings — unlike a drill, there is no duty cycle. Cell temperature rises continuously during long sessions. When the BMS detects cells above its thermal threshold, it cuts output to protect cell integrity. Let the pack cool for 10–15 minutes, then resume at a lower power setting to stay below the cutoff threshold.

Charger blinking red and refusing to accept the new pack after storage

Li-ion packs shipped or stored for extended periods can drop below the charger's minimum acceptance voltage — typically around 10V for an 18V pack. The charger sees the low cell voltage as a fault and blinks red rather than initiating a charge cycle. Most Steinel-compatible chargers have a recovery or boost mode — hold the pack on the charger for 10–20 minutes without interrupting contact, and the charger will trickle charge the cells back above the acceptance threshold. Once the pack reaches approximately 12–13V, the charger shifts into normal CC/CV charge mode and the indicator turns green.