Don't know if this will help or not----I had to have my inverter/charger repaired and while it was out they by-passed it so everything worked off of shore power or the generator BUT it would not charge the house batteries nor would they charge from the solar panel on top. Seems in order for the house batteries to be charged it had to come from the inverter/charger.
It can appear that the alternator isn't charging the house batteries...
I thought this was the case on my rig when I'd start the engine and watch the voltage across the house batteries. Didn't change. But then one day, I left my probes on longer and found that 2 minutes after starting the engine, a solenoid would close, and charge the house batteries from the alternator.
Since then, I've learned that the BCC (Battery Control Center) does the job of checking the chassis battery voltage after starting...waits until it's charged, then closes a solenoid to charge the house batts.
The older and weaker the chassis battery is...the longer the delay will be.
You're pretty close to right on partner. In the Fleetwood units, namely Bounder, there IS a Battery Control Center. And there's lots in that box. One of the many things in that box is a printed circuit board with a ton of functions. The one important component on that box is called a "Bi-directional, time delay relay". It's all explained here:
To me, this is facinating stuff. Most don't care how it works, just that it DOES work. Now, not all coaches have one of these but, some will have a variation of it. Diesel rigs will have something different than gas units and Fleetwood will have something different than Winnebagos etc. But, to all, if you get a chance, check this site out, it's old but I think much of the technology is still used today.
Scott and Karla SDFD RETIRED
2004 Itasca Horizon, 36GD Slate Blue 330 CAT
2011 GMC Sierra 1500 Ext Cab 4x4 Toad 2008 Caliente Red LVL II GL 1800 Goldwing KI60ND
I have a 2004 Holiday Rambler Imperial with the Cummins ISL. The charging current for my house batteries could be monitored with the Aladdin system. Mine would not charge the house batteries on a reliable basis. The system consists of an Intellec isolator delay relay that powers a large relay back near the batteries. When powered by the Intellec relay, that large relay connects up all the batteries to the output of the alternator.
The intellec relay requires that the engine batteries reach about 13.3 volts for several seconds (as I recall, some 30 sec) before sending power to the large relay which connects the house batteries to the engine batteries. This delay is to ensure that the engine batteries have a good charge before loading the alternator with the combination of house and engine batteries.
In my case, the voltage delivered to the intellec isolator delay relay was always lower than the voltage delivered to the engine batteries. This was because the voltage pick-up was from a wire that carried current for other loads, causing the resistive drop to lower the voltage to below the trigger point of the Intellec IRD.
To fix the problem, I had to add a relay which would sense the lowered voltage and connect the Intellec to a "real" voltage point. The intellec would then wait until the real voltage was above the trigger point and then connect everything together. It has worked reliably for the last 4 years.
In later versions, the Intellec IRD has been replaced by an Intellec Bi-directional isolator delay relay. (BIRD) The reason was that the BIRD would also allow charging from the Inverter/converter when plugged into shore power. Mine has a separate system for charging the house batteries.
I came across this post using a search, I too am unable to get my rig alternator to charge the coach batteries. I replaced the solenoid with no success.
I have a 2005 Winnie 31C, I performed the test listed in this post.
1. Put the key in the ignition and turned, the step retracted.
2. While on shoreline power and charging batteries I pressed the battery boost switch and was able to boost the rig battery from 12.5V to 14.4V ( no key in ignition )
3. Turned the ignition key only ( without starting engine ) and the rig battery jumped to 14.4V is this supposed to happen ?
4. Disconnected shoreline power, the coach batteries are now 13.2V, turned the ignition key and the rig battery again jumped up to 13.2v.
5. Now started the rig, voltage on the battery is 14.2V, coach battery 13.2V how long should it take for the alternator to switch from charging the rig to charging the coach battery ?
I RARELY work on Winne products anymore, but Winne for YEARS used that Battery boost for Boost and Dual charging. They used to use a button labeled DUAL/MOM. MOM was spring loaded and while pushed was the emergency start to use the coach batteries to start the chassis if chassis dead/low. The DUAL was a switch indent that you HAD to have in that position to charge BOTH battery banks. You left that switch in DUAL all the time, otherwise your coach batteries did NOT charge from the Engine Alternator. I do not know IF Winne still uses that system and if NOT when they stopped using it. Doug
Some OEM's use a immediate charge signal to the dual solenoid to charge BOTH battery banks.
1. Some use the delay by Intellitec that takes up to 3 or 4 minutes before it closes to charge
2. Some use a switch like my previous post on Winne that you must manually close to charge
3. Some like the Tiffin Powergear chassis have a delay for 10 minutes before the coach batteries get charge current.
4. They ALL should charge after at least 10 minutes.
5. Some Monaco products have a relay that disengages the Chassis Alternator IF you are traveling with the APU running. Once the APU is OFF, the Chassis Alternator then comes back to charge the coach batteries. Doug
Thanks for all your help, my model has a "boost switch" it is spring loaded and does not lock into one position. On the bright side when depressed I can hear the solenoid clicking. I will give the engine more time and take measurements.
I had the same problem and suspected a solenoid, but it turned out to be a fuse in the master battery control center. Check the fuses first and if all are ok, then check the solenoid. Another part of my problem was the the coach batteries would not get a charge while on shore power.
2013 Winnebago Via 25T
2002 Jeep Liberty Sport (Occasionally)