Im new to "off grid" but not new to electronics high and low power controllers

jpb2 Registered Users Posts: 1
There are a whole lot of posts to search thru to find what I am sure has been covered.. I cant be the only one. soo.... I was looking for some nomenclature help for my search targeting.

I have a group of 3 agm batteries, solar panels, an inverter, and a pro charge battery charger.
Currently I am using a propane generator to power a trailer. the generator has a remote on off switch.

here is my question (s)

1. Is there a low/high limiting switch (or relay type box) that senses battery voltage that will kick the generator on and then off after charging the batteries?

2. low voltage 11v on --- 12.9v off? variable adjust?

if I could get the right names I can do some spec looking but currently I cant find anything


  • BB.
    BB. Super Moderators, Administrators Posts: 33,476 admin
    Re: Im new to "off grid" but not new to electronics high and low power controllers

    Here is one, not cheap:
    Magnum Energy's Automatic Generator Start (AGS) controllers allows your generator to automatically start based on low battery voltage and/or high temperature. Two versions of the AGS are available (specify which when ordering from the drop down list):

    The ME-AGS-N is the 'network' version of Magnum Energy's Automatic Generator Start (AGS) controllers. The version is setup and operated via a Magnum Energy Inverter and ME-RC or ME-ARC remote panel.

    When using the ME-RC Remote, the ME-AGS-N has basic adjustments starting on battery voltage or temperature.

    When using the ME-ARC remote, the ME-AGS-N has advanced start and stop settings based on: Time of day, battery State of Charge, battery voltage, high temperature, or inverter load amps. Also includes the ability to manually turn the generator ON and off, generator exercise, warm up and cool down.

    The ME-AGS-S is the stand alone version that is similar to the ME-AGS, but works for an installation that does not include a Magnum Energy inverter.

    The Magnum AGS Controller can be configured for 12 or 24 VDC operation. It can also be configured for various diesel or gas generator brands and models. The controller’s default settings are set for "12 VDC" and "Diesel" operation. Refer to the owners manual to determine which setting is correct for your system.

    If you have a remote start configured genset, you could look at using a Battery Monitor with external alarm contact... It would be much more accurate than just measuring voltage itself.

    Xantrex Battery Monitor. You can program it to "turn on" at 50% and turn off at 85% State of Charge (or whatever numbers you want).

    I believe one or two models of Victron Battery Monitors also have this function.


    PS: Here are some voltage controlled switches too:

    Voltage Controlled Switch 10-60 VDC
    Morningstar Voltage Controlled Relay Driver

    Note that batteries are fairly sensitive to temperature vs charging voltages--Cold batteries require higher charging voltages--So if your batteries are in a variable temperature environment, setting non-temperature corrected set points may not be optimal.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset