Battery Monitoring System



  • Low voltage warning
  • Displays battery volts and amps, charge/discharge status, & remaining capacity
  • Battery Charging and Discharging indicator
  • Battery isolator switch

Compatible with any 12V lead acid battery

Monitor 12V battery state of charge.

The DrifterBM continuously monitors 12v lead-acid batteries. This unit makes an accurate estimate of remaining battery charge and allows the user to determine when a battery should be recharged. DrifterBM is compatible with any deep cycle 12V lead-acid battery including Valve-Regulated Lead-Acid (VRLA), Absorbed Glass Mat (AGM) and Gel batteries, as well as traditional non-sealed batteries.

The DrifterBM is permanently wired into your 12V electrical system and continuously monitors battery voltage and charge/discharge current. It uses this information, together with several parameters that are set by you, to model battery behaviour and to estimate actual charge in the battery. The current drain of the unit is only 3mA, which is much less than the normal self-discharge of a battery.


  • Large LCD screen for day and night viewing
  • Displays remaining time left in battery
  • Battery Charging and Discharging indicator
  • USB charging port
  • Clock and temperature gauge

Input Range

8V – 15V DC

Battery Drain

<3mA (backlight off, no USB-attached device)

USB Output

0.9A max, charger only

Ambient Temperature

0ºC – 50ºC


149mm x 85mm x 22mm


You can run an inverter with the Drifter.

The Drifter can take up to 80A constant, 1000A peak with the standard 100A shunt.

A 200A shunt is available which is rated to 160A constant, 2000A peak.

The Drifter is not compatible with lithium batteries.

The state of charge algorithms are programmed for AGM batteries only.