See Level II battery monitor reading doesn't make sense

[runtime]

Morning All,
I’m trying to figure out an issue I’m having with the volts reading, I’m getting on my See Level II monitor on my 2004 international.
When, I purchased the trailer back in April the battery volts on the monitor were reading in the 12.5 range.
The batteries were 6 years old, so I went ahead and replaced them with two new 12-volt deep cycle batteries. I don’t recall checking the monitor right after replacing the batteries but after my last trip I noticed the See Level monitor is reading the volts somewhere between 16 and 19 volts range. When I check the batteries with my multimeter, they are reading 12.66 volts. I also double checked, and confirmed the batteries are in a parallel connection. Other then the voltage reading on the See Level II monitor everything seems to be working fine.
Looking on-line it doesn't appear to be any need to calibrate the See Level monitor for volts.

Any input will be much appreciated.
Mike

[runtime]

Attached is a photo of battery connection

[uncle_bob]

Hi

Don't ask how I know this ......

If your converter / charger goes nuts, there is a thermal breaker between it and the battery. It will open up and let the converter go crazy. The voltmeter is on the converter side of things so it will give you the converter voltage in this case rather than the battery voltage. Indeed voltage up in the 19 to 20V range will fry various parts of your trailer. LED lights are one item on that list .....

So what to do:

1) Grab the trusty DVM

2) Pull the cover on the DC panel / converter charger

3) Plug in to shore power

4) Put the DVM on the output of the converter / charger and see what it reads.

If you are lucky, you have a blown SeeLevel and not a blown converter charger. In that case, replace the SeeLevel and move on. ( = there is no adjustment). If you are as lucky as I was, it's time to replace the converter / charger.

Bob

[SeeMore]

After the check suggested by uncle_bob, you should contact Garnet Industries (1-877-668-7813). They warranty the Sea Level parts for 1 year and, as you noted, battery voltage is not an adjustable reading/display value by the end user.

[dznf0g]

Originally Posted by SeeMore

You should contact Garnet Industries (1-877-668-7813). They warranty the Sea Level parts for 1 year and, as you noted, battery voltage is not an adjustable reading/display value by the end user.

What SeeMore said. I had a similar fault with my (then) brand new unit. It wasn't off by as much as yours, but it required a board replacement under warranty. Replacement has been fine since (several years). Note, it is normal for the SeeLevel to be a 10th or two below the voltage read at the battery posts, as the long run, combined with several connections, introduces resistance and a voltage drop. Mine is .1V lower than the actual battery voltage.

As noted above, ensure the converter is off and any solar input is switched off to help diagnose whether a charging error or a monitoring error. My money is on the SeeLevel board being bad.

[dznf0g]

It doesn't appear you have deep cycle RV batteries. The label appears to indicate cranking batteries. That's not the cause of your current issue, but they won't live long in a deep cycle environment, nor have as much capacity.

[SeeMore]

Originally Posted by dznf0g

It doesn't appear you have deep cycle RV batteries. The label appears to indicate cranking batteries. That's not the cause of your current issue, but they won't live long in a deep cycle environment, nor have as much capacity.

The SuperStart 24DVM is a 12v Marine deep cycle battery designed to withstand the rigors of long, deep discharges. No worries, the crank amps label is for trolling motor matching!

[dznf0g]

Originally Posted by SeeMore

The SuperStart 24DVM is a 12v Marine deep cycle battery designed to withstand the rigors of long, deep discharges. No worries!

OK, just labelled oddly. "Superstart" sounds like a cranking name. Also label has CCA, which is unusual. It's usually MCA for the hybrids like Interstate, and missing altogether with "true" deep cycles.

All marketing, I guess.

CCA is for cranking motors....not for trolling motors. It's a spec for high amperage, short duration loads, in cold ambients.

[runtime]

I just wanted to thank everyone for their suggestions.

I following up on uncle-bob's suggestion and used my DVM to check the volts at the D/C charger output and at various point on D/C system. All read in the 12.5 range or 13.2 if hooked to shore power. I also called Garnet as SeeMore suggested. They where very helpful and suggested I check pos and ground going into monitor. That reading confirmed 12.5 volts was going into monitor. Which pretty much confirmed its a monitor problem. While talking with Garnet, I also learned that my SeeLevel monitor/ model 712 is discontinued and the new monitors are not compatible with the tank strips used for the 712 model. Luckily, I was able to locate a 712 model monitor at Out of Doors Mart.

Thanks again for everyone's help.
Mike

[Shorty fish]

Finally got an airstream. We got a 2015 22fb and are super excited. Trying to learn it and well it’s not easy. Any help appreciated.

Ok so Its plugged into house. The battery disconnect switch is ON. Battery on the seelevel 2 tank monitor shows 13.3%. I kept the trailer plugged in so fan (think that’s the converter) is running but the battery juice isn’t going up.

So I kept the same setup but now took my battery charger, plugged inside the trailer, and the battery charger says 95% charged while airstream still says only 13.4%.

I must be doing something wrong any suggestions appreciated. Thanks!

[BradS]

Your battery meter is telling you you have 13.4 volts