Community Forums

SpursMVP · 08-24-2011, 07:42 PM

Hi everyone....I'm stumped. Looked through some of the old threads and didn't see an answer to my questions so here it goes.

We've got an '01 HR Endeavor and everything was working wonderfully 2 weeks ago. We returned from a camping trip, parked the MH and went on our merry way.

Went back to the MH about 2 weeks later and the batteries were dead (we have solar on the roof; however they're blocked by some trees right now). Anyhow I hooked up the shore power and it appeared to be charging and I could turn on lights, TV etc.

Well today, I went back to do some more checking and have NO POWER whatso ever.

Started at the source and verified that we have juice at the plug. Then pulled the cover off of the transfer switch and used my voltmeter to see if there was power inside the transfer switch and there was (this rules out the source and the power cable).

Next I went inside and checked the 50 amp main breaker and flipped it on/off a few times with no results. Hmmm.

Anyhow I checked the 6VDC batteries and found that I had boiled them dry (shame on me) and figure I'll end up replacing them.

My next step will be to turn off all power and pull the cover to the main circuit breaker panel and check the 50 amp main fuse to see if it is functioning or if any wires have come lose.

Once I have this pulled out and have verified that the wires are connected and the breaker is working, I was considering a test of the transfer switch by checking for voltage at the breaker box.

Are there any other tests or suggestions you might have for me? This one has got me stumped as the ONLY thing that works on the coach right now is the power step. No lights will turn on and there's no juice to the gennie either. Never seen a system drain like this before so I'm interested in any suggestions that you might have.

Thanks!

Drifter · 08-24-2011, 09:19 PM

See if you can start the generator. If you have power then, it most likely be the transfer switch......Maybe.

SpursMVP · 08-24-2011, 09:19 PM

Here's the latest. Went out to the coach and it started perfectly, so the engine batteries did not drain.

What's odd is that I still had the shore power hooked up and I could then turn on the lights. I know the alternator from the motor would be enough to turn these one, but what's odd is that I turned on the A/C units and they kicked in. Checked the inverter and it's now charging my house batteries.

This is beginning to 'smell like' the transfer switch because as soon as I turned off the diesel engine, the A/C units shut down and the lights began to dim. All of this happened while still hooked up to shore power.

The engine Alternator does not put out enough DC power to run 2 ceiling A/C units does it?

timdriver · 08-24-2011, 09:26 PM

Check your inverter and make sure the breakers on the inverter haven't tripped, my guess is they have since you boiled the water out of the batteries and might have caused the inverter to over heat.

SpursMVP · 08-24-2011, 09:35 PM

Quote:

Originally Posted by timdriver

Check your inverter and make sure the breakers on the inverter haven't tripped, my guess is they have since you boiled the water out of the batteries and might have caused the inverter to over heat.

I am embarrassed to say I had to add nearly 4 gallons of water to the batteries...wow! I know I topped them off a few months ago, but I figure having the solar connected may have expedited the boiling.

Anyhow, the inverter was tripped and is now charging the batteries. Lights are working too. I suspect I may have damaged the batteries by taking them down this low but we'll see.

Robi.1014 · 08-25-2011, 08:02 AM

Let's take some of the mystery out of what powers what on your rig. Accomplishing this may help explain your experience:

1. Steps deployed OK.
Reason: Steps are powered by the chassis batteries....the same battery bank that starts the main engine, powers headlights, dash A/C air, etc.
2. Your question: "The engine Alternator does not put out enough DC power to run 2 ceiling A/C units does it?"
Answer: no....for several reasons. First is that the alternator (driven by the main engine) charges the chassis batteries through production of 14 volts DC. But your roof air units need 120VAC....so no match there. But we need to take this a step further: Some rigs do have a charging path where the alternator will charge not only the chassis battery bank but also the house battery bank (your user manual probably states that this method of charging dead house batteries should not be employed). So, with the main engine running and with the house battery bank having some meager charge, your 12V house lights begin work, and MAYBE your microwave now has power (provided by the Inverter....because the Inverter draws juice from the house battery bank).

So that leaves open the question as to why the Inverter tripped off line. I don't have an answer. But I'll close by saying that the Inverter's output is not capable of running the roof A/C units....and thus there is no AC (alternating current) wiring present that would allow A/C units to be powered by the Inverter. A/C roof units get power from (a) AC shore power or (b) your generator's AC output. But here's a tricky thought: consider that the thermostat is run by 12VDC.....and if this little guy has no DC power, then the A/C roof units will not turn on. And maybe this is the "ah ha moment" ---> The 12VDC used by the thermostat comes from the house battery bank.

ArmyEOD · 08-25-2011, 08:26 AM

SpursMVP. sounds like your batteies went dry and the inverter triped after the charging part continued to try and charge the bats and it probley overheated causing the trip. Test your bats to be sure they are not toast. Also besure that your solar charger is working ok, boiling off 4 gals of water is a lot.

wa8yxm · 08-25-2011, 10:33 AM

I think you are doing just fine.. I would have measured voltage OUT on the transfer switch while I was there, but that is a nit. Voltage at the top of the MAIN breakers in the breaker box should be as good. If it's there, the transfer switch is good.

NOW: Question: Do you have an EMS? (enegery management system)

These are computers and in a motor home it is common practice to run all computers off battery power, I mean, why put in a whole new low amp power supply when you have one more than capable already "on board".. Thus it may be nothing more than the dead batteries bothering you.

Still, I would think some loads (The converter for example) would not run through the EMS.

Pusherpilot · 08-25-2011, 12:12 PM

I discovered a catch 22 in our MH a couple of weeks ago. The day before we left Mo for Cali I checked the batts and found one cell in one of the 4 6v U2200s dry. The are 7 yrs old. I filled it and after a few hrs it still hadn't taken a charge. A hydrometer check of the others showed that each had at least one "dead" cell except for one. After a couple of more hrs the previously empty cell had drained out on the ground again. It is cracked. We didn't have time to go buy new ones before we left so I figured we'd do OK without a/c while traveling and would start the genny if we needed it. That's when I learned that the genny starting circuit used the house batts. It would start if I did it with the engine running but not if it were off. So we learned to start the genny as we were heading into a rest stop before we shut down the diesel!!
We are now sitting in a CG in Corona Ca and will be hitting Sams Club for a new set of batts next week.
Ron

timdriver · 08-25-2011, 06:29 PM

I'll bet your batteries are shot it only takes a few dead cells for the converter to want to start charging like crazy trying to make up for those dead cells thus boiling the water out. I only bring this up because been there done that. I replaced all the house batteries and haven't had any trouble since. The reason the breakers on the inverter tripped is because it did overheat trying to charge batteries that had no water. Good luck to you and safe travels.

Alan24601 · 08-25-2011, 11:07 PM

Just replaced all four house batteries after I noticed they were dropping to 10.9 v over night. While doing that the engine batteries died, best to replace them all on age. Mine were six years old...

SpursMVP · 08-26-2011, 06:09 AM

Quote:

Originally Posted by Alan24601

Just replaced all four house batteries after I noticed they were dropping to 10.9 v over night. While doing that the engine batteries died, best to replace them all on age. Mine were six years old...

Thanks everyone for the great info. What house batteries do you suggest. We currently have 6 volt bats connected in series / parallel.

Dr4Film · 08-26-2011, 06:26 AM

Quote:

Originally Posted by Pusherpilot

That's when I learned that the genny starting circuit used the house batts.

We are now sitting in a CG in Corona Ca and will be hitting Sam's Club for a new set of batts next week.
Ron

Ron,

Why some coach manufacturers wired the generator to start off the house battery bank, makes absolutely NO sense whatsoever. What were they thinking! When boondocking and using the battery bank, you want the generator to start from the chassis battery(s) to charge the house batteries back to full.

If it were me, I would rewire it in your rear electrical run bay. Some people have done that. It just requires some new 2 or 4 gauge wire.

Quote:

Originally Posted by SpursMVP

Thanks everyone for the great info. What house batteries do you suggest. We currently have 6 volt bats connected in series / parallel.

I would do what Ron is and purchase a set from either Sam's Club or Costco if they are in your area. Otherwise, I would try your local NAPA or some other automotive supplier to get the 6 volt Golf Cart batteries, Interstate U2200 model.

Dr4Film ----- Richard.