Inverter quickly zapping 12 volt power

[DrSmart]

New trailer with very little use as of yet.

We have a 1200 watt Xanrex Freedom X inverter and a 21 cu ft Whirlpool residential fridge. The battery is a new 12v 130AH deep cycle. (group 31)
I wanted to test the setup before heading out on a trip so having house fed power to the trailer and the battery being fully charged, I tripped the main breaker off and turn the inverter on from the remote panel. The fridge cooling is off but the display is illuminated to indicate 'Cooling Off'. My problem is that the xantrex display is indicating 13.1 volts at startup and slowly drops to 12.1 volts in about 3 - 4 minutes. What can be drawing so much power? Has anyone else seen this happen?

[mini4mw]

Not that it wouldn't be right, but can/have you validated the volts at the battery? That's some pretty serious draw.

If it is valid, I'd cut the breakers to everything but the inverter and see if remains. If it does, process of elimination at that point; anything else plugged into inverter, unplug one at a time, if nothing plugged in then bad inverter?

[Grumpy]

You should have 2 batteries.. If you only have 1 the dealer didn't provide what they should have.

[Jeffur]

The draw 12.1 is not unusual

[us71na]

There are a number of phantom 12 volt users in your RV such as your CO/LP detector, the display on your radio, fridge controls, thermostat, Heat or AC controls.

[DrSmart]

Originally Posted by mini4mw

Not that it wouldn't be right, but can/have you validated the volts at the battery? That's some pretty serious draw.

If it is valid, I'd cut the breakers to everything but the inverter and see if remains. If it does, process of elimination at that point; anything else plugged into inverter, unplug one at a time, if nothing plugged in then bad inverter?

Thanks mini4mw. Once we head south and get into warmer climate, I'll follow that advice. The breakers shouldn't be in the picture though since I had tripped the main 50's. That should kill everything on the AC panel. I'll pull anything plugged into the inverter first to make sure it's not the problem. Then I can pull the DC fuses and narrow it down.

[DrSmart]

Originally Posted by Grumpy

You should have 2 batteries.. If you only have 1 the dealer didn't provide what they should have.

Thanks Grumpy. The dealer put in a small group 24 battery. I replaced it with the group 31 130AH. Even with parasitic draw, the voltage should not have dropped like that in 3 minutes. 12.1 volts is nearly 50% discharge. Two of these 130AH batteries in parallel would have lasted 6 -7 minutes. There's got to be something else going on.

[Grumpy]

Originally Posted by DrSmart

There's got to be something else going on.

Maybe, but they still should have given you two batteries.

Could be a defective volt meter in the control panel or even a weak or bad cell. Have you checked it with a volt/ohm meter. What happens with the truck connected and running?

[DrSmart]

Originally Posted by Grumpy

Maybe, but they still should have given you two batteries.

Could be a defective volt meter in the control panel or even a weak or bad cell. Have you checked it with a volt/ohm meter. What happens with the truck connected and running?

We hope to be on the road soon. I'll start doing some checks with the truck connected. The battery had been on a smart charger before putting it into the trailer today. The voltmeter indicated 13.1. I'll be doing some troubleshooting as soon as I can.

[Les7h]

I would think that you would want to be near your dealer for repairs - many dealers ask if you bought from them and then tell you to get lost Les

[poohbear]

Originally Posted by Grumpy

Maybe, but they still should have given you two batteries.

Could be a defective volt meter in the control panel or even a weak or bad cell. Have you checked it with a volt/ohm meter. What happens with the truck connected and running?

Don't you get more amp hours from (2) 6 volt in series if using the inverters ? As Abbot & Costello would say, " the big boys told me that "

[DrSmart]

Originally Posted by Les7h

I would think that you would want to be near your dealer for repairs - many dealers ask if you bought from them and then tell you to get lost Les

Sometimes the manufacturer provides faster support with direct shipping to your current location compared to having the rig sit at the dealers awaiting troubleshooting by their tech. I can test and prove where the trouble is. It might not be the inverter.

[DrSmart]

Originally Posted by poohbear

Don't you get more amp hours from (2) 6 volt in series if using the inverters ? As Abbot & Costello would say, " the big boys told me that "

Yes that's true, but the 130AH 12 volt battery that I'm using has some serious capacity and there's no way it should drop that quickly with or without the residential fridge running.

[Siamese]

Another thing that could cause the apparent voltage drop is your battery may have had just a "surface charge".

If a battery isn't fully charged, and you charge it until it indicates a full charge, and then disconnect the charger, it will have a surface charge which is not a true indicator of the state of the battery. The surface charge can be eliminated by waiting for it to go away, a process that is temperature dependent and can take anywhere from a few hour to a few days. Another way is to put it under a load to eliminate the surface charge and get a true reading. Which seems to describe what you're experiencing.

Meters get fooled very easily, and simply cannot be relied on until the surface charge is eliminated. You can get a much truer reading of your battery's state of charge using a hydrometer instead of a meter, as it isn't fooled by a surface charge. A hydrometer will set you back about twelve bucks.

A meter is a perfectly good way to measure a battery, but only if you know it's limitations.

Oh, and your battery is definitely not up to running your refrigerator for a useful amount of time.

[DrSmart]

Thanks Siamese. That could be a factor here. I've read about that factor where the battery is reading good voltage but isn't fully charged. I'm trying to avoid a hydrometer if possible but may go that route. The battery had been on a smart charger for 24 hours. It's quite interactive in sensing charge rate and maximizing battery capacity given enough time.

https://no.co/g15000

[poohbear]

Originally Posted by DrSmart

Yes that's true, but the 130AH 12 volt battery that I'm using has some serious capacity and there's no way it should drop that quickly with or without the residential fridge running.

You need 10 amp hrs per 100watts of appliances , again per the big boys. Add a 2nd 12volt battery at least, doesn't that unit have a place for one ?

[Jeffur]

Why would anybody expect a 12v battery to read much more than that when it is fully charged and there are no battery chargers or (other source of 12v charging) being supplied to it?

[RetiredOne]

Originally Posted by Jeffur

Why would anybody expect a 12v battery to read much more than that when it is fully charged and there are no battery chargers or (other source of 12v charging) being supplied to it?

I think the point is, a battery can show full volts sitting static, with no load on it. The magic happens under load, to see if it can continue to produce. A quick load test can give a pretty good indication of the condition of the battery, as it simulates a heavy load, and you can see how much the voltage drops.

[DrSmart]

Originally Posted by Jeffur

Why would anybody expect a 12v battery to read much more than that when it is fully charged and there are no battery chargers or (other source of 12v charging) being supplied to it?

It's the nature of a 12 volt lead acid battery. It's actually about 50% discharged at 12 volts. Doing this repeatedly can reduce the life of the battery considerably.

[mboy]

just make sure you have 2 6 volt batteries = 12 volts better system for you