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DStJohn · 07-21-2020, 04:16 PM

Hi there,

I'm new to airstreams and I'm running into a concerning issue. The 20ft Flying Cloud that I just recently picked up showed over 19 volts when it was hooked up to generators, and from what I can tell that's way too high for the (recently installed) Lifeline AGM batteries. The previous owner tells me he upgraded the converter to a Progressive Dynamics PD6400 series converter.

Is it possible that the wall panel is reading the wrong voltage somehow? I've seen it as high as 19 volts and as low as 17 volts in the first weekend that we went camping in the trailer. I wasn't able to find anything when I searched the forums, but it seems like something is seriously wrong if the voltage from the two AGM batteries wired in series is that high. Thoughts?

Thanks! Dylan

ROBERT CROSS · 07-21-2020, 04:22 PM

Did you actually hook the battery up directly the generator, or did you plug the trailer into the genset?

I believe 13.6 is the high limit on the Converter,
Could it be wired for 24v?

Bob
🇺🇸

dznf0g · 07-21-2020, 04:24 PM

Only on generators? What is it on shore power only? Yes, that's way high!

fran&frank · 07-21-2020, 04:25 PM

Cross check the voltage with a voltmeter at the battery. --Frank

stevejones · 07-21-2020, 04:44 PM

Quote:

Originally Posted by DStJohn

voltage from the two AGM batteries wired in series

What is the voltage of each battery? Are they 6V batteries or 12V batteries? If they are 12V batteries they should be wired in parallel, not series. Lifeline AGMs are 12V batteries aren't they?

Steve

dznf0g · 07-21-2020, 04:51 PM

Quote:

Originally Posted by stevejones

What is the voltage of each battery? Are they 6V batteries or 12V batteries? If they are 12V batteries they should be wired in parallel, not series. Lifeline AGMs are 12V batteries aren't they?

Steve

Lifeline makes both 6 and 12v agms.

dznf0g · 07-21-2020, 04:53 PM

DStJohn, turn off your master switch and post some pics of your batteries and their wiring....if you can. You're new here, so you may not have pic privileges yet.

pcskier · 07-21-2020, 05:22 PM

Is it same if plugged in to shore power? Just curious. In any case, when panel is reading 18v, put a multimeter across one of the batteries and see what it says. If it's 18 or 19v then yes that PD4600 (I think you meant that, not 6400) needs to be replaced IMO. Bulk voltage on that is 14.4V, so if you are truly getting 18V something is seriously wrong with the charger.

DStJohn · 07-21-2020, 07:14 PM

Thanks for all the replies everyone. I’m out at the airstream now so I’ll check a few things. A few quick responses:
- generators (Honda 2200’s linked together) were hooked up to the trailer through presumably the genset (electric hookup on the side of AS).
- batteries are Lifeline GPL-4CT 6 volt AGMs
- we haven’t hooked up to shore power yet, only owned the AS since Saturday
- I turned the switch in the AS to ‘Store’, is that the same as turning off the master?

I’ll take some photos of how the batteries are wired up, and multimeter readings. Thanks!

dznf0g · 07-21-2020, 07:29 PM

Yes store is the same as my reference to master. With it off, at least you wont be sending too high voltage to most all of the 12v components. What is the voltage reading with the generators off for an hour or so and the store switch to store position?

DStJohn · 07-21-2020, 08:43 PM

After checking with the multimeter, it appears the batteries are wired in series, one negative terminal wired to one positive terminal, and the remaining negative/positive terminals run into the airstream.
The good news is that with the multimeter it looks like the batteries are sitting at 12.7 volts (confirmed 6.34 volts for each battery independently as well). So I'm assuming something is causing my panel to show the incorrect voltage. Has anyone run into that issue before?

Unfortunately I forgot to bring the key to the airstream and wasn't able to check the panel, but I'm going to get back out there with the key and multimeter to check the panel and multimeter one after another, and then to check both again with the generators running, and both after the generators have run.

EDIT: This multimeter reading above is after the Airstream has been disconnected from the trailer and from the generators for a few days.

dznf0g · 07-21-2020, 08:52 PM

Were you using the AS shore power cord plugged into the ac receptacle on the generator, or utilizing a 12v port on the generator wired directly to the batteries?

nvestysly · 07-21-2020, 09:00 PM

The only way to accurately measure battery condition is with a voltmeter (as you've done) or to install a true Battery Monitor System (BMS). The equipment installed by Airstream is not a real BMS and what they installed may be wired incorrectly, installed in the wrong location, who knows?!

There are several BMS systems available at RV dealers and online retailers. Do some searching on Air Forums and see what works for you. BMS can cost as little as $200 or $$$several hundred depending on the other systems you might plan to install such as solar, etc.

I've installed both of the systems from Best Converter - the Trimetric in our trailer and the Expion in our van. Both work well. The Expion is by far much simpler but doesn't have nearly the functionality. There are lots of other brands of BMS but all use a precision shunt to measure the voltage, current, etc.

Randy at Best Converter is very helpful and ships parts promptly.

http://www.bestconverter.com/Battery...ors_c_281.html

dznf0g · 07-21-2020, 09:06 PM

I have the trimetric in my trailer as well as a self installed seelevel panel. I cant imagine how it could be miswired to display some 5 volts high. My seelevel reads .1v lower than my trimetric, which is completely logical considering how far it is from the negative buss and the shunt.

dznf0g · 07-21-2020, 09:13 PM

I just remembered something. I installed my seelevel probably 7 or 8 years ago. Out of the box, my display board showed an erroneous voltage. I cannot remember if it was high or low. They sent me a replacement.

DStJohn · 07-22-2020, 06:09 AM

Quote:

Originally Posted by dznf0g

Were you using the AS shore power cord plugged into the ac receptacle on the generator, or utilizing a 12v port on the generator wired directly to the batteries?

Shore power cord plugged into the AC receptacle on the generator, which should be 120V and 30amp.

Quote:

Originally Posted by nvestysly

The only way to accurately measure battery condition is with a voltmeter (as you've done) or to install a true Battery Monitor System (BMS).

Do most folks end up going that way and abandoning the SeeLevel gauge? Can I trust my SeeLevel gauge for the fresh/grey/black tank readings? If not, how do most people measure their tank levels?

Ack, I need to get back out to the AS and do some tests.

dznf0g · 07-22-2020, 06:31 AM

Quote:

Originally Posted by DStJohn

Shore power cord plugged into the AC receptacle on the generator, which should be 120V and 30amp.

Do most folks end up going that way and abandoning the SeeLevel gauge? Can I trust my SeeLevel gauge for the fresh/grey/black tank readings? If not, how do most people measure their tank levels?

Ack, I need to get back out to the AS and do some tests.

The Seelevel is probably the most accurate and consistent gauge system available today...but like everything else, it's accuracy is totally dependent upon the quality of the installation. The voltmeter is ok for a quick reference, but it just isn't a very sophisticated battery monitoring system. There is much more to the story than just voltage. I'd recommend the Trimetric system or Victron. Victron wasn't available when I performed my upgrade some 9 years ago or so.
The Trimetric is a very good system, but lacks some of the bells and whistles of a glitzy human interface.

dznf0g · 07-22-2020, 06:49 AM

Dylan,
Here's where I think we are and my recommendation. When you get to the trailer:

1) Measure the voltage at the battery posts again

2) turn on the store switch (no gennies hooked up) and compare the voltage in step 1 to the Seelevel reading. If they are different (Seelevel high and batt posts normal) we can probably stop and condemn the Seelevel board.

3) Turn off store switch and hook up gennies and fire them up. Check voltage at battery posts. Probably will be a bit north of 14v at startup and during bulk charging stage.

4) turn on store switch and compare battery post voltage to Seelevel. If battery reading is ~14v and Seelevel is indicating that ~17 - 19V, Seelevel board is bad.

tomsos · 07-22-2020, 09:21 AM

The SeeLevel gauge in my Airstream does not accurately measure either battery voltage or tank levels. In fact, battery voltage is way off. As others have said, best to check at the batteries with a quality voltmeter.

PB_NB · 07-22-2020, 09:34 AM

Quote:

Originally Posted by tomsos

The SeeLevel gauge in my Airstream does not accurately measure either battery voltage or tank levels. In fact, battery voltage is way off. As others have said, best to check at the batteries with a quality voltmeter.

I have to agree with you. Now that we have a Victron 712 BMV, it is easy to see how far out the SeeLevel reading is. Ours is out by under 1 volt. With the Victron unit installed, I don't need to consult with the SeeLevel.