Dead House Batteries/RS 2000/F41 Code

[Keith Duner]

Hello All:  Today I went into the coach and noticed that all 12V circuits are dead (2005 C9 Monterey 36 III, in great shape).  I keep the coach in a RV barn next to the house and usually keep it plugged in to 30A.  I checked and adjusted the water level in the batteries around March of this year and have not used the coach at all since then.   About a month ago I decided to unplug the shore power from the 30A service (I can't remember why but it seemed like a good idea at the time...).  Today the control panel on for the xantrex had a red light for code F41 and a yellow light for low battery.  The batteries were installed new last summer (both house and chassis).  I'm not the sharpest pencil in the box with the RS 2000 system but so far I can see that the charger is ON and currently in BULK charge mode.  I let it sit plugged in for a couple of hours and found the Red Light code F41 had returned.  I also don't hear the normal loud hum coming from the rs2000 although all the lights on the inverter/charger seem to be in the correct state.  I have all the documentation for the rs2000 and see that F41 refers to dead battery charger time-out and recommends restarting the dead battery charging once.  I'm not sure how to do that... is it automatic or is there a menu item that you can switch on?  I'm assuming that the batteries have drained to the point of being "dead" but given the fact that they are almost new and maintained correctly I would think that I should be able to recharge.  Any thoughts would be appreciated.   Thanks!  

[Keith Duner]

Well, the problem is solved (I think) but I have no idea why.  After posting the first question I went back to the coach and started the engine (fired right up).  After about 90 seconds the interior 12V lights came on and the red warning light on the RS 2000 control panel went out too.  So, I'm going to leave it running for a bit and then shut it down and see what happens.  I don't understand the behavior but the issue seems to have corrected itself (I think...).  Thanks anyway.

[Steve Huber Co-Admin]

Keith,
Run your generator to charge batteries that are deeply discharged. The load is too much for the engine alternator and can fry it.
Steve

[Joel Ashley]

Steve's right, Keith.  Perhaps the most common cause of alternator failure is people running the engine when the batteries have been discharged.  If the Xantrex is working right, patiently leaving it plugged in would be the best option now.

That's the one advantage of storing a rig outside... whether I'm plugged in or not (deliberate or forgetfulness), whether the main switches are off or on, the solar panel keeps the batteries up.

Hope you read our replies before your alternator suffers much.

Joel

[Keith Duner]

Thanks all for the information.  I didn't know about the potential overload to the engine alternator, thanks for the lesson.  I had shut down the engine before I came in to read the responses, so it only ran for maybe 10 minutes tops.  After I shut it down, the RS 2000 seemed to work correctly, no code F41 and the inverter/charger is making the "normal" sounds and appears to be charging the batteries (coach is plugged into 30A shore).  So, if I understand, there is a low voltage cut off point at which the rs 2000 will simply not work to charge the batteries.  But the batteries will still charge from the gen set or engine alternator (assuming no fundamental issues with the batteries)?  Love our Beaver but it's sure more complicated than the Itasca/Winnebago's we've had in the past.  Thanks again for the information, you folks probably save me a few bucks today!  

[LarryNCarolynShirk]

Keith,

If you have not replenished the water level in the batteries since March, they could be low on water.  You may want to check that before charging dry batteries any longer.

Larry

[Keith Duner]

Thanks Larry,  I'll chech them in the morning.

[Joel Ashley]

Try to never start the engine after disconnecting from shore, genset off, when your panel had been reading "Bulk" charge.  I like to have been well into the "Absorb" cycle before unhooking and cranking the engine, preferrably down to 14 volts or less on the panel.  Our alternators, though heavy duty, were not designed for bulk charging house batteries back from deep cycling over the length of time necessary, on top of their regular duty task of engine and chassis device operation.  They can and will overheat and burn rotor insulation, connections, circuit boards, etc. - as Steve says, they'll fry.  No cheap replacements out there.  Remember that whenever you've been dry-camping.

In a hurry to break dry camp?  Start the genset several minutes before the engine and let it charge the deep cycles for awhile as you drive, taking that load off your alternator.

Joel

[Gerald Farris]

Keith,
From your post above, it sounds like you are mistaken about how the generator recharges the house batteries. The generator can only recharge the house batteries with the inverter just like you do with shore power. If the inverter is malfunctioning, the generator will not recharge the house batteries.

Gerald

[Norm Green]

Gerald, are you saying that if the coach is plugged into shore power, it will not charge the house batteries unless the inverter is turned on?  I thought that I only needed to turn on the charger while plugged in.

[Edward Buker]

Norm,

I'll jump in to help out here....the charger portion of the inverter/charger has to be turned on with shore power or the genset running in order to bring the house batteries up to proper charge. The inverter portion or function does not have to be enabled, just the charge function. The genset has a really small built in alternator but it is tied to the battery set that is used to start the genset which are your chassis batteries. It will help charge the chassis battery set but is inadequate to handle any of the house battery bank charging.

Later Ed

[Keith Duner]

Gerald, Ed and Joel, thanks for the additional information, I didn't understand those details.  I had the charger portion of the RS 2000 enabled during this entire process.  While the problem seems to be behind me now I still don't fully understand the behavior.  The initial problem was no 12V power, a red light on the RS 2000 control panel and a code F41.  This occurred after about a month of being disconnected from 30A shore, but did not resolve itself after reconnecting to 30A shore for several hours. I twice cleared the code and it reappeared after about an hour (all while being plugged into shore). However, about 90 seconds after starting the engine the 12V lights "popped on" full brightness and the red light/code F41 problem went away.  The coach is in the barn plugged in to 30A shore now and all seems normal.  I think I'm still missing a piece of the puzzle.  Why did starting the engine seem to correct the issue?  Thanks for the continuing education.