why is my inverter alarm goin off?

i hav a 4000w inverter conected to four 6v 225ah bateries. two 100w solar panels chaging it. all r conected in series so all is 24v. bateries at full charge are 26v. but the charge controller is now showing my bateries r at 20v. i thot the inverter would shut down if it got too low. that alarm is anoying. are my beteries low? its not even half drained....

4 Answers

  • 10 months ago
    Favourite answer

    Hey Rebel, how old are your batteries? I’m guessing from what you’re posting here that one or two cells have died, that’s how lead acid batteries fail, one cell at a time. When this happens, during sunny days your voltage may very well be at 26 or 27 volts, but as soon as the sun goes down, the voltage falls quickly to maybe 20 or 22, depending on how many cells no longer hold a charge. Each cell should be 2.1 volts fully charged, maybe a little more during charge. Shut your system down tonight, wait 10 minutes or so then check the voltage of each 6 volt battery with a hand held voltmeter. My guess is some will read 6.4 volts or so, but some will read 4 volts, or even less. Once this happens that battery is shot, and what’s more is the others are taking all the extra charge voltage during the day, which accelerated their cells demise as well. Your inverter is alarming due to low battery voltage, if it gets much lower it will shut off automatically. Might be time for a new battery bank. We got 11 years out of our golf cart batteries before they started dying, my battery guy says that’s much longer than normal. Take care, Rudydoo

    Source(s): Home power.com
  • 10 months ago

    Yes your batteries are certainly low.  That is why the low voltage alarm is on.  You didn't mention what kind of loads you were running?  With this setup you would not be able to run any loads and lucky if you kept the batteries charged.  200 watts maximum feeding the inverter is hardly anything.  I'm assuming the voltage rating of the inverter is 24v?  If you want to power anything you will need several more 100w solar modules.

    Source(s): My source is 20 years as a General Journeyman with 7 years of designing and building solar installations.
  • khalil
    Lv 7
    10 months ago

    empty out the batteries liquids ... clean inside of them with sodium bicarbonate .... refill the liquids and recharge

  • 10 months ago

    Your voltages are way off.

    For cyclic use, charging then discharging, a 24V lead-acid pack should be at almost 30V (29.6V)when it reaches full charge (on charge).

    Anything less than 29V on a cyclic system will not work well.

    The batteries will need topping up with deionised water occasionally.

    For a float charge system where power is connected all the time, 27.6V.

    That's also safer for sealed batteries.

    22V off load (possibly 10V on heavy load) is considered completely dead and going lower can damage the batteries.

    26V on charge for a 24V pack will put very little energy in to them, it's below the minimum float charge voltage; they will never really charge.

    More info: https://batteryuniversity.com/learn/article/chargi...

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