Electrical issue - Batteries stop charging on shore power

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Liamlunchtray
Posts: 12
Joined: Sun Oct 17, 2021 10:44 pm

Electrical issue - Batteries stop charging on shore power

Post by Liamlunchtray »

Hi All -
I just purchased a 2011 27RSB on the E450 chassis. I'm having a perplexing electrical issue. The rig has a Xantrex Freedom 458 Inverter/Charger and a Generac QP-40 Generator

During our inspection our NRVIA inspector noted that the batteries were at 9v and need to be replaced. The seller had a tech out and was told that they just needed to be charged. That seemed questionable to me, but I let it go.

Last week we picked the unit up in Florida and drove it home to Rhode Island. First night the house batteries were at 10v after 4 hours of driving and unable to start the generator. I swapped them out with some new cheapies from Walmart. Generator fired right up, and everything worked great. We parking lot camped the next couple nights on the way home. I was unable to get the inverter going to run my CPAP, so we ran the genset at night. It worked fine and charged the batteries without issue.

We got the unit home and plugged it into shore power (dedicated 30 amp circuit). It works fine for about 20 minutes, then stops charging the batteries. The 120v outlets stay powered, but the batteries will start to discharge. At around 9-10v it starts a low battery alarm and eventually shuts off all 12v systems. If I start the truck about a minute or two later I hear a relay CLICK and all 12v systems come back online. The display shows the batteries charging and all is well. For troubleshooting I ran through the setup info on the inverter and made sure that battery type and AmpHr were configured properly. I set the input circuit to ">30A" which should disable any load sharing.

So long story short - Batts charge fine off alternator or genset, but the charger shuts down after a few minutes on shore power, and quickly drains until the 12v systems turn off. Is it a flakey inverter/charger? A bad transfer switch of some sort? Something else?

Any suggestions would be much appreciated!
Liam
tomzleapin
Posts: 485
Joined: Sun Jun 20, 2010 9:15 am

Re: Electrical issue - Batteries stop charging on shore powe

Post by tomzleapin »

First thing is to check your breakers in the distribution panel. It's a good idea to switch each breaker off then back on again. If this doesn't work you may have a serious problem. Your inverter/charger has a built-in transfer relay. If this relay has gone bad you will probably have to send the inverter in for repair. The click you hear is your battery isolator. This is a solenoid that engages and parallels your engine battery with the coach batteries.
Tom
2005 24' RB
Towing 2016 Mini Cooper convertible on tow dolly
New Hope, MN
Liamlunchtray
Posts: 12
Joined: Sun Oct 17, 2021 10:44 pm

Re: Electrical issue - Batteries stop charging on shore powe

Post by Liamlunchtray »

tomzleapin wrote:First thing is to check your breakers in the distribution panel. It's a good idea to switch each breaker off then back on again. If this doesn't work you may have a serious problem. Your inverter/charger has a built-in transfer relay. If this relay has gone bad you will probably have to send the inverter in for repair. The click you hear is your battery isolator. This is a solenoid that engages and parallels your engine battery with the coach batteries.
Yep, already went through all the breakers and turned off/on. It does seem to charge the house batts off utility for a period of time (5-10 minutes maybe) and then it stops. I had been leaning towards it being the inverter/charger, but I wasn't sure if there could be anything else I was missing or if there was some other type of switch/relay that switched between generator and shore.

We're wanting to move to Lithium and that would require a new inverter/charger anyways, so its not the end of the world. I was hoping to get better acclimated to the coach before I had to make that upgrade. I'll have to start figuring out which unit is as close to a direct drop-in replacement as possible.
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shilohdad
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Re: Electrical issue - Batteries stop charging on shore powe

Post by shilohdad »

I don’t have your setup, but we do have and inverter/charger. Ours is from Outback. If the input voltage drops below a certain level, the charger stops working. Can you check to see if for some reason reason your input voltage is low? I would find it strange on a dedicated 30 amp line that you would have that problem, and only after several minutes, but, hey, it’s something to look at.
Joe and Lucinda
Tonto, Meadow and Shadow, the papillons
Shiloh and Morpho at Rainbow Bridge
2017 Spirit
Formerly 2006 24RB
Liamlunchtray
Posts: 12
Joined: Sun Oct 17, 2021 10:44 pm

Re: Electrical issue - Batteries stop charging on shore powe

Post by Liamlunchtray »

shilohdad wrote:If the input voltage drops below a certain level, the charger stops working. Can you check to see if for some reason reason your input voltage is low?
Yes, I was thinking the same thing. I have a Surge unit with a voltmeter at the outlet - I'm seeing 117v-121v at the outlet, which should be well within spec.

I went ahead and ordered a new inverter/charger off Amazon. Its returnable within 30 days, so if by any chance it doesnt do the trick I'll send it on back. We'll see how it goes.
admoffat
Posts: 27
Joined: Sun Nov 08, 2015 8:50 pm

Re: Electrical issue - Batteries stop charging on shore powe

Post by admoffat »

We had this problem with our 2016 coach. The problem was a fused relay on an inverter board. We had to have the board replaced.

We decided that what caused the problem was that we had the coach shore power plugged into an outlet that had a GFI. GFIs don't like surge loads. In the coach, we had a small electric heater plugged in to an outlet to keep the coach warm. At some point, when the heater kicked in, it tripped the GFI in our home. The inverter had to switch from shore power to the house batteries under load. After doing this enough times, the inverter relay gave up and fused shut.

We've been able to charge batteries that were quite low in voltage, but there's a limit to how much abuse like this batteries will take. At some point they won't charge, or won't hold a charge and you'll have to replace them.

Good luck with the conversion to lithium. There are lots of posts about that in this forum.
2016 Royal Splendor
Verona, WI
davids.moffat@outlook.com
Liamlunchtray
Posts: 12
Joined: Sun Oct 17, 2021 10:44 pm

Re: Electrical issue - Batteries stop charging on shore powe

Post by Liamlunchtray »

So I went ahead and swapped out our Xantrex 458 Inverter/Charger with a new Victron Multiplus. I thought it was ok intially, but no dice.

Symptoms are the same - after a while on shore power the DC systems see a drop in voltage and eventually go dark. If I start the truck, there is a delay after a couple minutes, I hear a CLICK from a relay, and all 12v stuff comes back to life. We have run the rig overnight on Generator without issue - it seems specific to shore power.

In a unit with an inverter/charger are the DC systems powered by the inverter/charger or from a converter like you would see on a coach that has no inverter? From my line of thought the issue is likely either the convertor, the battery isolator, or the automatic transfer switch. Am I missing anything? I haven't had a chance to start going through everything with a voltmeter and I'm dropping it off for new graphics tomorrow so I probably have a week before I can start digging into it. I did find a new automatic transfer switch in one of the storage compartments that had been shipped from Born Free to the original owner some years back. It doesn't look like its ever been installed - I wish the folks I bought it from had more background information on it.
Liamlunchtray
Posts: 12
Joined: Sun Oct 17, 2021 10:44 pm

Re: Electrical issue - Batteries stop charging on shore powe

Post by Liamlunchtray »

Well for those playing along at home - I got it resolved. After I swapped the Inverter/Charger the behavior improved and 12v loads would run longer, but the batteries would eventually die. Process of elimination brought me to the converter. Got a new one (upgraded Lithium compatible version ) and when I went to swap it out I found that it was not just packed with dust and dog hair, the 120v input was entirely disconnected. The weird thing is that the 20amp breaker that is listed as being for the converter is being used to run the inverter. The converter is only 725 watts, so I landed it on the open 15 amp breaker and all is well.

I should have checked out the converter first, but I was planning on upgrading the inverter anyway, so no harm no foul... Now for some lithium and solar....
melamax
Posts: 4
Joined: Mon Feb 14, 2022 8:22 pm

Re: Electrical issue - Batteries stop charging on shore powe

Post by melamax »

I am using Dakota 200AH,...Inverter is 3000 watts, Works very well. Dakota replaced a faulty 200 No Problem, great to deal with, Victron solar to 12V was to replace Chinese junker off amazon, Renogy on top, 4x100 thinking I can fit 2 more maybe..Currently have mini split 38SEER, can run off solar maybe 2-3 hours hence more panel idea..But now can eat cool lunch at rest stop on solar... Love it.. Art Krause
Liamlunchtray
Posts: 12
Joined: Sun Oct 17, 2021 10:44 pm

Re: Electrical issue - Batteries stop charging on shore power

Post by Liamlunchtray »

Art - do you have any pictures of your mini split install? I’m debating one for better solar performance, but I’m having a hard time envisioning where the interior air handler would mount.
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