Community Forums

cjatx · 05-31-2023, 04:33 PM

I have a 2007 Newmar Mountain Aire DP with four house batteries and two chassis batteries.
I recently changed storage facilities. The old facility had a 50 amp plug. I always had the coach plugged in to keep the batteries charged without any issues.
The new facility only has a 20 amp outlet. I used a dog bone adapter to plug in, but the power doesn't seem constant. The load meter bounces from from 20 amps to 30 amps and then turns off, then comes back on and cycles through again. I can also hear the power converter switching back and forth between battery to shore power.
I don't want to damage anything so for now I have it unplugged and in store mode, but prefer to plug in and keep the batteries charged.
Has anyone experienced anything like this before?
Thank you,
Chris

8.3Oilbuner · 05-31-2023, 04:53 PM

Hi cjatx; I think your Newmar has a lot more load draw than my 01 Windsor with the same amount of batteries. Your source for your 120V 20 amps might not be too reliable. Just guessing. I would not want to have my coach plugged into a power source that might not be able to handle the load. If the only items in the coach you need kept up are the batteries I would go out and buy 2 smart 120V battery maintainers and put one on the house batteries and one on the chassis batteries. That way no worries about voltage going in through the inverter/charger systems. Let the battery maintainers do the job. That way everything inside the coach should be protected. This is just my opinion on the way to handle the problem you are having. Lots of owners out there with a lot more electrical experience than me. I just know enough to be dangerous!

JGrosman · 05-31-2023, 05:01 PM

Why not just go down to WalMart and buy a small battery charger. Plug it in and connect it to your batteries.

hclarkx · 05-31-2023, 07:17 PM

Suggest you use the 120V circuit breakers to switch off all loads except the converter. The power draw should be well under 10 amps with only the converter charging or maintaining the batteries.

Ray,IN · 05-31-2023, 07:17 PM

Quote:

Originally Posted by JGrosman

Why not just go down to WalMart and buy a small battery charger. Plug it in and connect it to your batteries.

Yep, or simply remove the negative battery cables after the battery banks are fully-charged and forget about plugging in to shore power for the winter.

Lead-Acid batteries self-discharge approx. 3% per month.

Captain8 · 05-31-2023, 07:36 PM

Sounds like you're pulling a ton of power. Victron inverters allow you to set the shore input power limit and also set the inverter to charge only mode. Also their cerbo allows you to monitor power input/output.

You should at a minimum have some shunt to measure the battery usage and see what it's doing.

For your coach you could flip all breakers except the inverter and set the inverter to charge only if possible. Another option is to flip the battery disconnect and connect the batteries to a simple battery tender. Get a 2nd for the starter batteries

Bigd9 · 05-31-2023, 07:38 PM

Quote:

Originally Posted by cjatx

I have a 2007 Newmar Mountain Aire DP with four house batteries and two chassis batteries.
I recently changed storage facilities. The old facility had a 50 amp plug. I always had the coach plugged in to keep the batteries charged without any issues.
The new facility only has a 20 amp outlet. I used a dog bone adapter to plug in, but the power doesn't seem constant. The load meter bounces from from 20 amps to 30 amps and then turns off, then comes back on and cycles through again. I can also hear the power converter switching back and forth between battery to shore power.
I don't want to damage anything so for now I have it unplugged and in store mode, but prefer to plug in and keep the batteries charged.
Has anyone experienced anything like this before?
Thank you,
Chris

Your Mountain Aire probably has a sophisticated charger built into the inverter. I believe what you are seeing is just the charger trying to "bulk charge" the batteries thinking it has 30 amps to play with. What I do is go to the energy management center and press a button telling it that I only have 15 amps to play with. It will then limit the charger to that maximum.

In my coach, when it is first plugged into shore power, the charger comes on "full blast" until the batteries reach a set point then it tapers down. If the batteries are good, the charger will settle down and draw only a few amps or less for the rest of the time.

cjatx · 05-31-2023, 09:05 PM

Thank you for all the input. I didn't mention earlier that I have everything including the refrigerator and air conditioning switched off. I'll try turning all the breakers off except the converter and see if that does it.
As a last resort, I can try putting trickle chargers on the batteries. Unfortunately, my storage unit is very narrow so the door over the batteries won't lift all the way up. It requires some gymnastics to actually connect the chargers.

2004Horizon · 05-31-2023, 11:44 PM

Something sounds wrong. Any outlet that swings current like you described, do to a shorting load, would normally blow a fuse. How are you measuring current, BTW?

I'm guessing you have an Inverter/Charger combo and you are relying on the charger to keep your house batteries charged when you store your RV.

I think this requires you to leave your battery disconnect (aka saleman switch) "on." Is that correct? ...If so that's a mistake.

And then your coach probably uses a Trick-L or Amp-L relay (or whatever they call these things, which fail often) to combine your house batteries to your engine/start battery so your house batteries will charge off your alternator. Is that correct? ...Fis so, these old relay are always causing problems.

====

My guess is that your charger is failing or it's your Trik-L or Amp-L relay is shorting out. So please let us know what type of inverter/charger you have? And if you have a BIRD or Trik-L or the like? Not that it matters so much. What is more important is that your inverter functions normally and you disable the charger on your power panel. Then disconnect the small Tril-L wires to your battery solenoid so it is no longer functioning.

====

I presume like you inverter (quasi-sine or modified that it probably is) well enought that you do NOT want to upgrade to a Pure Sine Wave inverter, and I don't blame you. Why spend the money if your current inverter is getting the job done.

So here's what I would do:

1) Buy a Victron AC-DC, 17A charger and stop using your charger in the inverter.

Amazon sells it for $144.

https://www.amazon.com/Victron-Energ...2-63e904010ad0

Note: I doubt you need more than 17A, but Victron makes 25A model for a little more money. When I have shore power I typically have it for more than 3 days so that's plenty of time to fully charge your 4-6V-GC2 house batteries. Plus the Victron has FAR BETTER charging algorithms vs. the crappy charger in your inverter. In fact, I would say everyone should turn off their working charger in a Dimensions or Magnum or Xantrax inverter/charger and start using the Victron as their primary house battery charger -- and you will find you almost never need to add water to your batteries more then 1x/year. Which means your house batteries will last 4+ years since you are not going to "fry" them like your old charger is probably doing to them now!

A) Wire the Victron inside your bedroom so you can plug it into a room wall outlet for power when you are camping and you have shore power.

B) When you store your RV you just unplug the Victron from the inside wall outlet, open your tip-out bedroom window (if you have one) and run a long outdoor extension cord to the Victron to power it. (That all. Easy. Reliable. And the Victron has bluetooth so you can monitor your charging amps on your Victron cell phone app!)

2) Stop leaving your salesman switch on when your coach is in storage.

3) Remove that Trik-L or Amp-L relay and install a Keyline VSR (140A) between your house and engine battery to combine them this way. This is a more reliable 2-way relay that will not fail.

https://www.amazon.com/Dual-Battery-...NsaWNrPXRydWU=

Winemaker2 · 06-01-2023, 04:51 AM

Quote:

Originally Posted by cjatx

Thank you for all the input. I didn't mention earlier that I have everything including the refrigerator and air conditioning switched off. I'll try turning all the breakers off except the converter and see if that does it.

As a last resort, I can try putting trickle chargers on the batteries. Unfortunately, my storage unit is very narrow so the door over the batteries won't lift all the way up. It requires some gymnastics to actually connect the chargers.

My storage spot has a 20A recepticle and I prefer the approach 8.3Oilburner mentions.
I avoid the attaching issues by using the 12V leads with ring terminals that came with my BatteryMinder and have them installed permanently. I have also mounted a recepticle in the batty bay and permanently wired an extension cord to the house batty batty bay ( actually the bay next to it to keep the maintainer clean & dry with just 12V leads to the house bank).
Both maintainers stays connected. The recepticle in my chassis bay has an extension cord that reaches the storage location recepticle to provide power... plug it in and maintainers are working.
I used a basic 1.5-2.0 A unit for chassis battys but went with a selectable 2-4-8 A unit for my 8- 6V GC2 house bank.

Sent from my SM-T878U using iRV2 - RV Forum mobile app

2004Horizon · 06-03-2023, 05:10 PM

OP 8.3Oilbuner and I are saying almost the same thing. I agree, almost with this...

I would not want to have my coach plugged into a power source that might not be able to handle the load. If the only items in the coach you need kept up are the batteries I would go out and buy 2 smart 120V battery maintainers and put one on the house batteries and one on the chassis batteries. That way no worries about voltage going in through the inverter/charger systems. Let the battery maintainers do the job.

What I am saying improves on this same approach, but maybe if I rephrase the concept then more people will understand.

The Victron AC-DC Charger (17A or 25A) is both a charger and battery maintainer. AND!!! AND!!! When you install a VSR you combine your engine battery with your house battery... SO... GET THIS... you only need 1 Victron AC-DC Charger and not 2 battery maintainers, then... AND GET THIS... Victron is also bluetooth enabled, which means so you can monitor and change your charging parameters on your cell phone.

This Victron works GREAT for me and now I no longer am replacing my house batteries every 2-3 years!

...But because I realize other people may not grasp what I am saying, let me rephrase: I am highly recommending you mount your Victron inside your bedroom and STOP... REPEAT STOP... using your old charger inside your Magnum or Dimension Inverter/Charger combo. (Just turn it off at your power panel.) Why?

...Because you will no longer be boiling the sh*t out of your house batteries, with that antiquated charger, and now, using the Victron, you can count on 5 years+ of FLA battery life, and won't that be nice? Plus, this method solves your coach storage concers.

==> Up to you! It's your dime!

==> And if you store your RV outside, then adding solar will always keep BOTH your chassis and your house batteries "maintained" at full charge so you don't need shore power at all. (Just unplug your Victron and let the VSR do all the charging off the solar controller.

wolfe10 · 06-03-2023, 05:25 PM

For accurate advice, please tell us what converter, inverter/charger, etc you have.

I would be surprised if you don't have a smart inverter/charger.

If so, use the "power save/power share" feature to select 5 amps. That limits 120VAC amp draw to 5 amps. WAY more than you need to keep the batteries charged (over 40 amps @ 14 VDC).

Everything else OFF. That includes engine block heater, water heater, etc, etc.

20 amps is PLENTY for storage.

RV Driver · 06-03-2023, 05:42 PM

Something is wrong with the OP’s setup. My 2006 coach has been plugged in to a regular 15-amp outlet for years when in storage with zero problems.

It keeps the batteries charged, and I’ve even run one of the ACs on this shore power setup.

Bigd9 · 06-03-2023, 05:43 PM

Basically what I said Brett. Just use the energy management system to limit the charging amps and your done.

2004Horizon
I've been using the coach inverter/charger systems for 23 years now with two different coaches. I've never changed the starting batteries, and my house batteries have lasted on an average for 8 years. These chargers are smart chargers with step down functions built in. Once the batteries reach a predetermined voltage, the charging rate decreases to the minimal amount the battery manufacturer recommends.

The OP has a 2007 Mountain Aire. It is almost the top of the line back in the day. It's made to function without having to keep up with addons.