The NASA Battery Clipper BM1 is a compact 12V battery monitor that measures terminal voltage and current, calculates state of charge and estimates time to charge or discharge.

• Supply voltage: BM-1 12V — 8–16 V DC
• Supply current: 1.5 mA
• Battery capacities: 5–600 Ah
• Maximum load current: 100 A
• Maximum charge current: 100 A
• Shunt: standard 50 mV at 100 A
• Voltage & current monitoring, resettable amp‑hour counter and starter battery input

The BM1 combines amp‑hour integration with an adaptive internal battery model (including Peukert's equation) to deliver accurate state‑of‑charge tracking without frequent re‑synchronisation, all while drawing a mere 1.5 mA. In the box: display, 100 A shunt with M8 ring terminal and 5 m cable.