Inverter issue

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I had some difficulty with my inverter. It was telling me that there was too high of a voltage in the batteries and was shutting down and would not re-start.I did a voltage test on the batteries every thing was fine. I started to look around all the connections and fuses to see any complications. I found a loose connection at the negative cable (main inverter cable) on the battery post. Tightened the connection,the inverter fired up.
Now I am a little skeptical about the inverter,why was the inverter saying the batteries were too high in voltage? Is there something else going on or was it that simple of a fix??

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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
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    Re: Inverter issue

    Welcome to the forum.

    Could you give us a little more information to work with? Specifically what inverter.

    This happens a lot with inexpensive 12 Volt inverters: some of them can not take the higher Voltages involved in battery charging. I'm not saying this is specifically the problem in your case, just that some inverters are more Voltage tolerant than others.
  • Whatever
    Whatever Registered Users Posts: 2
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    Re: Inverter issue

    The inverter is a Trace 1500 watt 12 volt(1998 vintage) .Batteries are 6 v Surettes 1 year old. Array is Bp 100 watts (3).
    Gen. is a honda 5000 watt inverter type
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
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    Re: Inverter issue

    Not surprised at its being 12 Volt.

    I think your loose connection may have been the whole problem: depending on exactly how it is wired, the inverter might have seen higher-than-normal Voltage from the panels until the wire was clamped down tight because the battery was "left out" of the current path and couldn't pull the panel Voltage down.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,479 admin
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    Re: Inverter issue

    Only reason I can think off--If the battery charger (AC or solar) was attempting to charge the battery bank through the same "loose" connection--The charge controller output voltage can exceed ~15 volts (typical cut off for many inverters) because the battery is not "supplying a load" to the charge controller.

    Otherwise, it is possible you are seeing an inductive kickback from wiring (or even the inverter transformer). The inverter "fails" because of low battery voltage, turns off, and an inductive kickback (again, poor connection to battery bank) trips the over voltage sensor (usually this would be the "wrong" polarity--but I guess it is possible it still confuses the inverter).

    In the end, you figured out the problem and fixed it :D. Checking connections (cleaning/tightening) can fix many problems for off grid systems. The combination of low operating voltage and very high currents are very picky about connections and wiring resistance.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset