Battery/ inverter question?

[tommymsw]

So I am new to this. New to me, OLD RV. I've just been fixing it up and I am almost finished.

I bought a little "cigarette lighter" inverter. It works fine in my car. But when I put it in the RV (plugged into the lighter outlet in back) the light is orange (Indicating over or under amps).

I do NOT have a battery in the RV right now. My question is, do you think that the inverter is doing this because the converter is bad? (It shows almost 13amps when I test it, but my car shows almost 16). OR... Do you think this will all go away when I add the battery? Like the converter will charge the battery and the battery will give the proper amps to make the inverter work? Or is that stupid?

Maybe when I am hooked up to shore it does not even go through the battery?

[tommymsw]

Sorry for the confusion... Yes, I meant that the lighter outlet is giving off around 12.9 VOLTS. I get this by placing a meter in the lighter outlet. My RV is an 84 and the lighter outlet is in the same place it always was. While the wires are not as thick as the AC wires, they are pretty darn thick. And again, I am getting almost 13V through it.

I do plan on ONLY running something small from it (like a small laptop) or charging a phone. I guess I will try running a new wire from the battery (but I assume this means I have to have the battery in for it to run, and it will not run off the converter as it does now).

Running a new wire will be a heck of an undertaking though... I think I will have to rip up the floor to do it.

It is odd that it works fine in my car... You would think it would be the same thing with the wires. Even LESS in a car.

EDIT>.. I checked the wiring and it is 12 guage.

[wa8yxm]

Lighter sockets used to have nice SOLID wiring that had no problem with 20 amps. but today they are not called Lighter sockets any more.. They are "12 volt accessory outlets" and .. Well, abut all they are good for is charging a phone, running a map light or a small fan.. Inverters often want 10 or more amps and that is pushing it. The wires are too small and too long to provide that kind of current.

[MEXICOWANDERER]

Nyet on the load. A cigarette lighter element sucking max amps at 10 volts could care less. Your inverter with a 70 watt load is fussy. You need to run a TEN GAUGE FUSED WIRE from the battery to the socket and then a larger wire from the socket to chassis negative.

Resistance Is Futile

[RJsfishin]

Other than having your amps and volts a bit confused, the answer to your question is yes,.....inverters hate low voltage and must be close to the battery. So, get your house battery(s) installed, and make sure they are getting 13+ volts when engine is running, and you will likely not have any more problems w/ the inverter. If you do, the wiring between the inverter and the batteries is probably too small.

[Community Alumni]

I have a small coffee grinder that I bought specifically because it is only 70 Watts @ 120V. Rather than start up the generator first thing in the AM, I have an inverter that is appropriately sized. In two different RVs there was not enough power to operate the grinder. Simply put, if the gauge of the wire from the source to the 12V outlet is too small, the resistance will cause a voltage drop and the inverter will give you a low voltage warning. From what I have seen, the outlet can only handle charging a phone, tablet or small notebook computer. Lucky for me, there was a power port in the dash of the Sprinter connected to the chassis battery capable of running an inverter with a load up to about 150 Watts @ 120VAC. For any inverter to function correctly, it should be hard wired directly to the source with wire gauges appropriate for the distance to the inverter.

[2112]

How are you drawing and measuring the 13 Amps? Is that 13A DC going into the inverter or 13A AC coming out of the inverter?

As others have said, do not draw more than 8A DC out of that cigarette lighter type plug.

[MrWizard]

I think you mean 13v on the battery, i think you mean over or under volts

or do you mean the inverter has a LOAD display showing how much you are using

most likely the that plug is too far from the battery with too small a wire
and the inverter won't operate with LOW voltage

cig pulg is good for approx 8amp approx 100w of power

13amps would be about 150w of power, 16amps would be 200w of power

[time2roll]

Most RVs are 8 amps max to those cigar connectors. Long thin wire connection will plague you with low voltage. Best to wire direct to the battery.