Sargent Modular Series Systems

Installation and wiring: wire the extra LB series battery into the vehicle's 12V system first, and connect its magnetic communication cable to the Sargent Control System's CAN bus. Before paralleling two batteries, make sure both are fully charged to the same voltage, to avoid a big rush of current between them the moment they're connected.

Changing the battery address: adding a second battery in parallel means changing its communication address from the default '1' to '2', so both can talk to the system at once - only have the battery you're changing connected via its comms cable while you do this (the steps are the same on the 4" EC940 and 7" EC970 screens).

Configuring single or dual batteries: the display needs the Sargent Lithium+ battery switched on in the ADVANCED SETUP menu first, or it won't communicate with it - choose Lithium+ for a single battery, or Lithium+ x2 for a dual setup.

Information displays: once configured, extra screens appear in the Control Panel's POWER menu. On the EC940's 4" display, a dual setup's two batteries are combined into one figure (two 70Ah batteries show as 140Ah total); on the EC970's 7" display, tapping the battery symbol switches between Battery 1 and Battery 2's individual readings.

Installation and wiring: mount each sensor on the tank's top surface, close to the middle, to avoid reflections off the tank wall and reduce variation when parked on a slope. Fit a side-mounted overflow too, so a sensor doesn't end up sitting underwater after filling and skewing its readings - and note the sensor isn't suitable for tanks with a sloped or irregular base, which will also throw off readings.

Configuring the sensors: enable the Sargent Ultrasonic Water Sensors in the ADVANCED SETUP menu first so the display can communicate with them, and enable the relevant tank too for its level to actually show - any tank not configured for ultrasonic sensing is assumed to have a traditional rod/stud sensor instead.

First-time calibration: the sensor automatically starts calibrating its tank depth the first time it gets 12V power, so make sure it's fitted and the tank is empty beforehand for an accurate result. Once calibrated, it sends regular readings (roughly every 5 seconds for fresh tanks, 10 for waste) - and since it can't read fluid closer than 30mm to its own face, the 100% level gets set 30mm below the measured tank depth. Re-calibration can be triggered any time from the Advanced Setup menu, either automatically (again, with the tank empty first) or manually if you'd rather enter the tank depth yourself.

Information displays: once set up, each sensor's data appears under the WATER menu, reading in 1% steps rather than the 25% steps a rod/stud sensor uses. The EC940's 4" display shows fresh and waste levels on separate screens (use '>' to switch), while the EC970's 7" display shows both together on one screen.

To link a Webasto Thermo Top EVO heater to the Sargent MC100 Control Unit (for control via the EC970 panel), you'll need two extra Sargent parts: the Fan Adaptor PCB (17464) and Fan PCB harness (89003-24). Wire it up following the diagram for the Webasto-to-Sargent connections - note that harness cable colours in the standard Modular System kit (K970A) may differ on OEM installations.

For setup help with the heater itself, contact Webasto directly or check their portal at https://my.webasto.net/en/. On the Sargent side, enable the Webasto Thermo Top from the ADVANCED SETUP menu first, which then adds a 'Heating' option to the home screen for controlling it - the Help button in the top-right corner explains each individual control.