Chateau with Sprinter Chassis battery issue

[thorapy]

We have a 2013 Sprinter chassis with a 2014 Thor Citation 24SR coach, purchased new this year. Just returned from a 2 week, 3300 mile trip and found that our coach batteries (2 12 volt, Harris batteries) are d-e-a-d. During the trip, we boondocked for 5 nights in a row at one point and noticed the coach batteries were pretty dead... Understandable, although we had driven at least 5 hours on each of those days and use very little power when we're parked (1 or 2 lights and the water pump to do a few dishes).

We stayed with family and plugged into a house outlet for 24 hours, then drove to a campground with full hookups and plugged into a 30 amp outlet for about 14 hours the next day. After driving 800 miles during the following 2 days and running our generator for 90 minutes, we barely had enough battery to bring in our 2 slides.

Once home again, we called Thor, MB and Harris Batteries about the issue. The Thor rep seemed to think that Mercedes PROHIBITS the chassis battery from trickle charging the coach batteries, that they are not connected. MB wasn't sure about this.

Does anyone know if Mercedes prohibits the Sprinter chassis from charging the coach batteries? If so, does anyone have a work-around? We really don't want to have to camp in a full hook-up lot every other night to charge the batteries. Thanks!!

[FW28z]

You could always "borrow" boating technology and install a battery combiner such as a BlueSea ACR.

[HarryT]

I recently purchased a Thor Four Winds Siesta 24 SA on a Sprinter Chassis. I was not sure about the charging system so I went out and checked it out today. The house batteries charge on the Converter charger. The engine while running charges the chassis batteries and the house batteries.
Hope this helps;
Harry

[FW28z]

The way you can tell for sure is to measure the voltage across the house batteries with the vehicle engine off, then measure again with the engine running. You should see about 1V increase in voltage on the house batteries if they are being charged by the vehicle engine (which is the alternator charge voltage).

[thorapy]

FW28z and HarryT thanks for your replies...
Here's what we have found out (confirmed by Thor by phone)...
Thor does not install a battery isolator in any of their Thor RV's that specifically have a Sprinter chassis.

We had been puzzled because our coach batteries seemed to charge when we drove but emptied quickly. The battery monitor lights would go up to full when we finally arrived at our destination; however, 15 mins of having a light on, the chassis battery monitor would quickly go down to 1/3.. and then 30 mins later to empty.

Bottom line: Thor told us MBZ doesn't allow Thor to put the isolator between Sprinter and chassis batteries for helping to "trickle" charge the coach batteries, instead you need to drive with your generator on if you really want a fully charged coach battery when you arrive at your destination.

HarryT..our Thor is a Citation 24SR. I would be curious if Thor tells you that you "do" have a battery isolator between your Sprinter and coach batteries, thus allow your coach batteries to charge while you drive without your generator running. Can you let us know what you find out?
Thanks again--

[FW28z]

Batteries can sometimes "recover" a bit after non use. As you use a battery, the internal temperature raises... the heavier the load, the higher the temperature.

When the battery is allowed to rest, the temperature returns to normal, which can give the illusion there is more charge in the battery than there was after you used it.

Perhaps this is what is giving you a false reading and making you believe the batteries were charging? It's probably an extreme condition, but who knows.

So plan "B" might be to install a solar panel or two on your roof for recharging the batteries while you drive down the road.

Of course, that means you need to drive places were it is sunny all the time - but is that a bad thing?

Thing is, the conventional wisdom is for the longest life, never let deep cycle batteries go below half-charge. Kind of makes the term "deep-cycle" an oxymoron doesn't it?

[blw2]

Originally Posted by FW28z

You could always "borrow" boating technology and install a battery combiner such as a BlueSea ACR.

I'm with him. i would install one of these gizmos.
and if you boondock a lot I would install a solar system as well.

I have been on the fence about solar. I want to install a small one, not for boon docking really, but just for a little recovery and maintaing against parsitic draws durring storage...... then I think if I'm going to that trouble, i might as well install a small system with controller to get a liitle advantage for an occasion off grid stay. We historically always have hookups, but now that we have the motorhome, i can forsee an occasional stay at a truck stop and such....

And on another note.... I think we all should call and pestser Thor for schematics. I have tried and they won't release it. I want both plumbing and electrical schematics for my coach, so that I can undertand these systems better and also for future trouble shooting. I really don't want a generaic one size fits all either.... they very likely already have one for each model anyway. We shouldn't have to wonder and guess about how to operate these things. It's not that hard Thor!

[FW28z]

I got a "schematic" from Thor for my 28Z a few months ago. It did not show how everything interconnected, but rather where all of the various components were to each item and the color-code - more or less.

I bet the only other thing they have is a wiring harness schematic, which I did not ask for.

I was also able to obtain the location of the aluminum ribs and steel attachment points for the coach'es superstructure.

If any one else has a 28Z and would like a copy of what I have, then PM me and I will send it to you. We're leaving in the morning for a week vacation so I might not get back to you until we return - but I will get back with you - I promise.

[FW28z]

We ended up having to boondock at a state park last week as we have yet to buy (at least then) a 25ft 30A extension. The power pedestal was about 45ft from the coach, so we boondocked for the night.

We used up about 25% of the coach batteries overnight, which I thought was a bit much. Other than we paid for electricity on our site that we could not use, we got by just fine. We put the fridge on gas mode, and luckily enough we did not need the microwave or air conditioner.

We now have a 25ft @ 30A extension power cable.

[blw2]

Originally Posted by FW28z

We ended up having to boondock at a state park last week as we have yet to buy (at least then) a 25ft 30A extension. The power pedestal was about 45ft from the coach, so we boondocked for the night.

We used up about 25% of the coach batteries overnight, which I thought was a bit much. Other than we paid for electricity on our site that we could not use, we got by just fine. We put the fridge on gas mode, and luckily enough we did not need the microwave or air conditioner.

We now have a 25ft @ 30A extension power cable.

ugh. I have a HD 15Amp RV extention cord that I thought about throwing in the coach just in case, but in my 5-1/2 years with my popup never needed it so I figured I would save the weight. I don't know the gauge off the top of my head, but it's heavy. I have run my coach's Air Conditioner through it at home, through a dog bone....

I can't even imagine what your site must have looked like that you couldn't pull closer! here' in my area of FL, I can almost always get within inches of the post in the State Parks..... at least within 5ft or so....

[FW28z]

The pedestal covered 4 sites. Had the pedestal been in the center of the 4 sites, it would have worked, but it was far from being centered.



This was at Tahquanemon Falls State Park in Michigan's Upper Penninsula. Most state parks have pedestals within 10 feet of the coach, but occasionally they are somewhat distant. Even then, some sites had pedestals a lot closer than this one.

I think perhaps the pedestals have been there awhile, and some of the sites have been re-arranged as the trees that grow taller and larger may block off access to the original campsite arrangement.

While the State Parks are relatively nice, they are mostly over 50~75 years old, so they typically have electricity, but there is no water or sewer hookups at each site. Water is usually available at many locations throughout the park, and there is a dump station on-site, but not at each location.

As well, there are not a lot of "big rig" friendly spots, although most campgrounds have a few. Remember though, these sites have been there for a long time... certainly long before there was such a thing as a big rig.

Still, $25 is the typical going rate for sites, so for that price, those inconveniences are minor.

[blw2]

Ah, can't say that I've seen an arrangement like that yet!
Hard of course to tell by the picture, but eyeballing it, it looks like I could have come close to reaching with the factory drop cable in mine..... I can't remember now if it was 25ft or 30ft. AMybe if I angled back towards that picnic table a bit....

Anyway, having that ability to run while disconnected is one reason I elected to go with a motorhome. I'm glad you were able to make it work!

[FW28z]

It was about 25ft from the pedestal to the picnic table. I did have an extension cord (only 16AWG so not enough to power the RV), that I used to charge the cell phone.... but there was no cell phone service either as we were literally in the middle of nowhere.

[oreddie]

We dry-camped at Crater Lake in Oregon for three nights in late August and were very frugal with electric; lights on only as needed, water pump on when needed and Fantastic Fan on for perhaps 4 hours total over the stay. There's a blue light on the front of the 12v tv in the "bedroom" that I assume shows that it's in ready mode, a bit annoying in an otherwise completely dark cabin, so I unplugged that as well.

We had to run the generator twice for about an hour to keep the batteries indicating 1/2. I wonder if this might be more related to the quality of the batteries Thor installed as our dry camping battery experience with another Sprinter-based model was much better.

2015 Citation Sprinter 24SR

[thorapy]

Oreddie, last month we were able to verify with the Thor factory that the house batteries are not connected to the Sprinter chassis battery at all in our 2014 Thor Citation 24SR with a 2013 Sprinter chassis. Apparently, Mercedes made this change in 2014 for Thor/Sprinter configurations--the Thor rep did not know why this change was made, nor did he know if other Sprinter/RV makers or years were affected.

This information was new to our Camping World sales manager, as well as the Thor rep we met here in Denver (he called the factory to verify the info and was surprised to hear it!). The folks at Camping World were surprised too and actually replaced our totally-drained house batteries. They recommended that we camp with electric hook-ups at least every 3 days or run the generator (which can be done while driving) for 2 hours per day to keep those house batteries charged.

Sounds like your 2015 Citation MAY have the same disconnect between the house and chassis batteries--best to check with the guys at Thor before totally ruining your house batteries like we did.

[oreddie]

Wow - that's really good info! Many thanks. I'll check with Thor for sure and share the rely here.

Anyone using solar to keep charged? Perhaps that's already on another thread. I researched and almost bought but so many choices and conflicting info. I just want to extend the time we can dry camp, not run the whole house on sunshine.

[Ultra Limited012]

I have a new 2014 Thor Chateau 31A on a Ford E450 Chassis. I picked up my new unit in June of 2014 and while winterizing the unit in November I notice a problem with the Harris deep cycle battery. I was plugged into a 30amp outlet and the inverter was over charging the house battery to the point that in boiled it dry and damaged the plates to the point that the battery needs to be replaced. In researching this problem first of all I found the battery was probably as old as the chassis which was delivered to Thor in May of 2013. So by the time I bought the unit the battery was already 13 months old and probably had not been maintained per the manufacturers specs. Monthly check of fluids, charging etc. My second thought on this is that the house battery has a switch near the entry door that basically enables or disables the battery. If this switch is left on after you plug into 110V the inverter will continually charge the battery thinking it is discharging when in reality your 110V inverter is running all of the 12 volt systems. When I disabled the battery with the switch the inverter immediately stopped trying to charge the battery. The Harris battery is a fairly cheap install for Thor. I plan to replace this battery with an AGM sealed battery. AGM batteries can take over charging much better, resistant to cold freeze,, no need to add water, will not spill or overflow, resistant to shaking and movement issues and last much longer than standard lead acid batteries. I would think there would be a switch installed to prevent the house battery from being over charged if left on, but apparently not. It will also charge off the alternator when traveling, but I doubt it would overcharge from the alternator. One more weird setup is the front dash radio, DVD unit does not run off the chassis battery. It only runs off the house battery or the inverter being plugged in. To drive an use the in dash radio, you have to have the house battery switch in the on position.

[FW28z]

Originally Posted by Ultra Limited012

I plan to replace this battery with an AGM sealed battery. AGM batteries can take over charging much better, resistant to cold freeze,, no need to add water, will not spill or overflow, resistant to shaking and movement issues and last much longer than standard lead acid batteries.

Actually, I think it is the other way around. AGM does not take overcharging very well (at least the overcharge rate needs to be lower), and you will need to replace the Converter/charger in your coach for one that specifically charges AGM batteries or you can damage it. I doubt the converters that Thor supplies are capable of charging AGM.

AGM chargers typically require lower trickle charge rates; - a standard trickle charger intended for lead acid batteries is too high for AGM.

If your charger/converter is damaging your deep cycle battery, there may be an issue with it as it is supposed to have a trickle charge position. But the chargers are relatively cheap, so you may simply want to buy a better charger.

While you can most likely install one that has AGM capability, the risk here is your engine alternator could possibly damage the AGM house battery as it is not designed to charge them - and in reality, you are combining the engine's battery with a coach AGM battery on the same alternator/charge circuit.

Also, Thor used to connect the stereo system to the engine battery - that is how mine is wired up (2011). They changed this in 2012 or 2013 because of the propensity of running the stereo when you are camping, which alleviates the possibility of discharging the engine battery while you are parked.

Probably either way is OK as if the engine battery is discharged too much (stereo hooked to the engine battery), you can emergency start the engine with the house battery; and if the house battery is too discharged (stereo hooked to the house battery), the engine alternator will recharge the house battery during operation.

Unless, of course, Thor changed the house charge setup. On my 2011 coach, the engine alternator will charge the house battery.

[blw2]

Originally Posted by Ultra Limited012

.......If this switch is left on after you plug into 110V the inverter will continually charge the battery thinking it is discharging when in reality your 110V inverter is running all of the 12 volt systems. When I disabled the battery with the switch the inverter immediately stopped trying to charge the battery......

I'm trying to wrap my head around what you are saying here. Can you please elaborate what you mean?

[Ultra Limited012]

Originally Posted by blw2

I'm trying to wrap my head around what you are saying here. Can you please elaborate what you mean?

The 110v shore power will run all 12v systems thru the inverter. If the battery switch is left on it is also supplying power to the 12v system. Can these two power supplies be left on? Or if the 12v house battery is turned on while the inverter is running will the inverter over charge the battery? That's what was happening to my RV, the inverter was over charging my house battery. When I flipped the house battery switch to off, the inverter immediately stopped charging the house battery.