Possible dead batteries -

An AGM battery can be Load Tested - disconnect the batteries and then fully recharge them. Typically, discharge at 1/2 the CCA Rating or 3 times the 20 Hour rating. The mfr will specify minimum holding voltage after 15 seconds discharge. Now, you will know if the batteries are good or not.

"100% is from the meter, after the shore power has been disconnected."

Any solar? Same thing if it keeps the voltage above 12.6--the meters will show "full" Also while the 7-pin is connected and the engine running. Unless it is the battery fuse, depending on where the solar and 7-pin cuts into the path.

Since the battery disconnect was closed, the next culprit might be the battery fuse/DC circuit breaker on the positive post of the house battery bank being the "open."

You do need a portable voltmeter to confirm that if the converter output at the battery lugs inside the rig at the DC fuse panel is 13.6, then you should be seeing 13.6 at the battery posts. If not--you have to find the open by working back along the pos and neg paths between battery and converter.

BFL13 wrote:
"Left the house all was 100%"


When you are plugged in, your meters will show "full" even if the batteries are dead, because your meters are just showing voltage. Your converter will be doing 13.6v and a full battery is 12.7v, so the meter thinks the battery is full seeing that voltage above 12.7.

If for some reason you have the battery disconnect "open" at home, the batteries are not getting any charge from the converter, but the rig's 12v systems will indeed be 100%--from the converter.

Meanwhile the batteries are dying. So you get to the campground and try to use the batteries and they are in sad shape. Plug in, and you are good again--converter on the job.

BTW, a trick (for trailers) so you can use a low battery on arrival to run the jacks or whatever before you plug into shore power, is to leave the 7-pin connected and leave the engine running, so the alternator can keep the voltage up. I suppose with a MH you need to push some button or other to get the same result. :)

100% is from the meter, after the shore power has been disconnected. . .

Battery cutoff is "closed" and i checked all the wires and connections to see if they were tight..

"Left the house all was 100%"


When you are plugged in, your meters will show "full" even if the batteries are dead, because your meters are just showing voltage. Your converter will be doing 13.6v and a full battery is 12.7v, so the meter thinks the battery is full seeing that voltage above 12.7.

If for some reason you have the battery disconnect "open" at home, the batteries are not getting any charge from the converter, but the rig's 12v systems will indeed be 100%--from the converter.

Meanwhile the batteries are dying. So you get to the campground and try to use the batteries and they are in sad shape. Plug in, and you are good again--converter on the job.

BTW, a trick (for trailers) so you can use a low battery on arrival to run the jacks or whatever before you plug into shore power, is to leave the 7-pin connected and leave the engine running, so the alternator can keep the voltage up. I suppose with a MH you need to push some button or other to get the same result. :)

OK is it really GELL or more likely AGM?
GELL is not that common and could be overcharging at 14.4 volts and they often have limited acceptance amps.
AGM charging at 14.4 is fine but is too high for float mentioned early in the post. High amperage charging is actually good with AGM.
I speculate the battery could have diminished capacity.

Best to post the exact battery make/model along with the converter model to verify the charging profile matches the battery.

wolfe10 wrote:
Two good questions.

Add to them:

Are you leaving the inverter on while driving?

If so, what 120 VAC things are on? Said another way, what is the draw on the batteries (in amps) times time driving. That will tell you how many amp-hrs you drained from the batteries.

Inverter is on, only 1 outlet is powered by it, that is for the residential fridge... I can drive from PA to FL with no battery issues last year, not the case now.

time2roll wrote:
Have you checked the battery water level?
Have you checked that the truck connector is supplying 12v power while in transit?

Gel cell, no checking the water levels...
I did check that, it is supplying power

Two good questions.

Add to them:

Are you leaving the inverter on while driving?

If so, what 120 VAC things are on? Said another way, what is the draw on the batteries (in amps) times time driving. That will tell you how many amp-hrs you drained from the batteries.

Have you checked the battery water level?
Have you checked that the truck connector is supplying 12v power while in transit?