DC Power Intermittent

[Christian Fish]

Everything worked normal a week ago. Got in the coach on Sunday to show it to some friends. 30 amp plugged in and both battery switches on. When my wife started to extent the PS slide, it went out a few inches slowed and stopped. No obvious DC power in the coach, Aladdin dead, no lights, & Hydo-Hot inop. AC electrical outlets below the sink had power as did the convection oven. I was able to start the generator with no change in the conditions. Then I went out and disconnected the 30 amp power and started the engine. Still no DC power. We outside and checked the batteries and associated fuses and relays in the battery compartment, all looked normal. Then I checked the electrical compartment below the driver’s window. Again, all looked normal. When I went back inside, the DC power was on, all looked normal. I shut the engine off and retracted the slide and about 30 seconds later, the DC power clicked off.

Based on what I have read here I suspect it might be the Salesman Switch. Any other ideas?

[Christian Fish]

I couldn’t get back to the coach until last week due to having my right knee replaced. It is stored at my cabin 2 hours away. When I got there, the chassis batteries were dead, but the house batteries were fully charged. It has been plugged into 30 amp power with both battery switches on. The generator wouldn’t start even using the boost switch. I could hear the rapid clicking of the fuel pump but it wouldn’t crank over. I was able to start the engine. While I was there, I replaced the chassis battery switch and bypassed the coach power solenoid.
Yesterday I went out there thinking I needed to clean the Big Boy relay. Both the house and chassis batteries showed full charges with shore power disconnected, but the generator still wouldn’t start. I reconnected shore power and the generator started right up. Everything seems normal now with the exception of a W205 code on the Xantrex inverter. It has something to do with the AGS system but I can’t find a reference in the Xantrex manual.
The generator runs fine when the coach is stationary, but shuts down after a couple of minutes if I start it while driving. I’m not sure how to chase that down.

[Bill Lampkin]

Call  Xantrex customer service at 1-800-670-0707. They are very helpful. If they give you a list of trouble codes, please post it here and let us know what they say.

[Steve Huber Co-Admin]

W codes are shown for the RS20000W  on pg 4-8 in Coach Assist.
Steve

[Bryan Beamon]

Christian, on your gen not staying on while moving could be a loose ground cable on the frame to the gen.

[Carl Boger]

My Coach is wired up a little different than yours, but I initially had a problem with the chassis batteries dying but the house batteries being charged.  I found that the Cat motor keeps a slight drain on the chassis batteries, and that my MH did not have the "optional" echo charger.  I installed a echo charger and now all batteries are staying topped off while plugged into a 20 amp circuit. 
The rest of my low voltage gremlins also went away and the circuit breakers in the 12 volt power distribution system under the drivers area no longer were tripping. 

Maybe if your chassis batteries get to a full charge some of your other problems will also go away for you.

[Fred Brooks]

     Christian,
After reading your post a couple of times, I think this is the scenario that transpired based on the info you supplied. Seeing that the batteries and salesman switch were on, I also believe the Inverter was on but in "standby" because the coach was plugged into shore power. If you lost power at the cabin, then the inverter came back on line and started using up the house batteries. If the house batteries fall below 10.5 volts, the inverter/charger will not charge them once shore power is restored. Once you started the coach, the alternator gave the house batteries just enough of a surface charge for the inverter/charger to recognize them and start the bulk, absorb, and float sequence. If you had the generator set for auto start and you started it from the "remote panel" , once it realizes that the batteries are fully charged it understands it has no reason to be running so it shuts itself back off. Hope this helps, Give me a call at 520-309-1260 if you want to talk further.
  Merry Christmas! Fred

[Joel Ashley]

I like your analysis Fred, but I’m not clear on why his inverter’s charger wouldn’t charge after restoration of shore power... why the 10.5v criteria?

Joel

[Fred Brooks]

   Joel,
That is a good question, I am not sure why it is engineered that way. If you call Xantrex or Magnum and inquire for that generation of inverter/chargers, they will tell you that is the way they react to "dead" batteries. I have fielded this question from customers who call me and state that their charger quit working. I have advised them to start their engine and slow idle it just long enough to raise the house voltage to the required threshold for the inverter/charger to come back on line and start the charging sequence. If they don't want to do it that way, put a trickle charger on the house batteries and bring them back slowly and then the inverter/charger will finish the job. I am guessing that 600 amp rating of house batteries is a serious stress test for any inverter/charger to deal with from a "dead" condition. That is the other reason to be "kind" to your alternator and not "fast idle" the engine under these conditions. Hope this helps, Fred

[Eric Maclean]

Fred
I suspect your right they probably are looking at the charge rate required to bring up an effectively dead battery and are trying to eliminate the possibly of inverter/charger damage or battery damage caused by the heat generated from very high amp rates the charge system would try to deliver on a bulk charge.
Totally dead batteries should be charged at a lower rate until they get to a reasonable state of charge to avoid the build up of heat and the damage that can create (plate warpage and shorted cells)

On another note most alternator manufacturers will tell you not to charge f!at or overly discharged batteries using the alternator the reason for this is that even though the alternator may be rated at 100 or 160 amps which it can and will product the design characteristics (usually size) limit it's cooling capacity (air flow) hence longer periods of high amperage output creates over heating of the alternator stator effectively damaging the stator by cooking the stator insulation .

The inverter manufacture could have programed the chargers to ramp up amperage slowly on a dead battery but from a design point of view they probably figured that if the system was plugged in and working there should be no reason for the batteries to be dead in the first place and the extra design would cost more to build effecting the produces profitability.

Just some thoughts to consider.
Hope this helps
Eric