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behengold's avatar
behengold
Explorer
May 27, 2016

Invertor power consumption

My new to me RV came with a xantrex freedom 458 invertor with two new 8D AGM batteries.I set the panel for that type of battery. How long should those batteries last with a tv and fan going? The reason I ask is I'm seeing a drop from 12.5V to 12V within 1/2 hr according to the display panel.Will the panel alert me if the batteries drop too low.How much power do one of these invertors draw sitting idle? Should I turn the invertor off when I'm not using 120V? Thanks

37 Replies

  • I disconnected the power and it dropped down to 12.5 amps on the display panel. I had set the incoming charge to 10 amps. I'll leave the invertor on overnight and see if the batteries drop further with the power unplugged.
  • 12.7 or so. A tv and a fan shouldn't drag down the batteries like that.
  • I replaced them after I bought the rv last fall. Panel shows 13v with power plugged in.How high should the voltage start out it if fully charged?
  • 12.5 as a resting voltage sounds pretty low, even for agm. I agree with smkettner, batteries are not charged, or are sulfated (ruined)

    how do you know the 8d batteries are new, is there a date code or receipt?
  • I have it plugged in to my house right now. I usually store it and have a 100 w solar panel to maintain the charge. Right now it shows 13v on the batteries.
  • Maybe 2 amps at idle should last about 100 hours. tv might cut that time in half.

    I suspect the batteries are not charged or they are sulfated. What is your charging routine and voltage? Possible other items are draining the battery such as incandescent lighting?

    Yes I would turn off the 458 when not expected to use in the next hour.