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

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.

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.

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 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?

12.7 or so. A tv and a fan shouldn't drag down the batteries like that.

Invertor power consumption | Good Sam Community

behengold
Explorer
May 27, 2016
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.
time2roll
Nomad
May 27, 2016
AGM can rest at 12.9 to 13.1 volts. (fully charged, disconnected 48+ hours)

Does the 458 show charging amps? When charging do the amps taper to maybe 10 or 5 amps before voltage drops from 14.3 to 13.3?

Are you reading the remote panel for voltage or do you have a meter right on the battery terminals? Are you sure the connections are clean and tight? What size 458?

http://www.xantrex.com/documents/Inverter-Chargers/Freedom-458/Freedom458(445-0193-01-01_rev-2).pdf
2oldman
Explorer II
May 27, 2016
12.7 or so. A tv and a fan shouldn't drag down the batteries like that.
behengold
Explorer
May 27, 2016
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?
GordonThree
Explorer
May 27, 2016
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?
behengold
Explorer
May 27, 2016
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.
time2roll
Nomad
May 27, 2016
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.

Forum Discussion

Invertor power consumption

About Technical Issues

Related Content

Measuring 12v power consumption

OIL Consumption

Invertor Turns on and off frequently

Power Pedestal Connections

Shore Power??