Originally Posted by outlaw557
I was always under the impression that the alternator had nothing to do with the house batteries, apparently this is incorrect
and when the engine is running I get a sulphate smell...imagine the batteries are screwed as well. So anyway, the batteries do not charge when plugged in, I assume that the converter/charger is not working properly or at all.
Am I correct in thinking this? Has anyone else ever had this issue?
Thanks for any response.
For quite a few decades now, about 99.9999999% of the motor home manufactures out there, have had chassis's that, when driving down the road, the alternator DOES CHARGE BOTH SETS of batteries. Not sure why you were under the impression that they (the alternator) did not charge the house batteries. I mean, think about it. If you're camping, remotely (boondocking) and, your house batteries are run down, and you wanted to go to another spot for camping, and your drive was for a hour or two or three, you'd still end up with run down house batteries when arriving at your next destination, correct?
So, that's why the alternator DOES charge both sets. Now, just how each manufacturer sets up the charging procedure, is a bit different on many makes and models. One many Winnebagos and Itascas, there is a specific solenoid that handles that duty. In fact, in many models, it's a DUAL DUTY solenoid. That is, it couples the house batteries and the chassis batteries for engine cranking if, the chassis batteries are low in voltage.
After the engine is started, that same solenoid, electronically engages and, couples the house batteries with the alternator for re-charging.
Now, dose your coach have this type system? Maybe, maybe not. You'll have to investigate to make sure.
As for charging either set while on shore power, that's a totally different setup. On most diesel coaches, there's an Inverter/Charger that handles those duties. And even then, on the earlier models, only the house batteries were charged while on shore power or generator power. It only in '06 that Winnebago started offering the "Trik-L-Start" system that couples the engine batteries for charging from the Inverter/charger.
On gas coaches, most of the time the unit is a Converter/charger. And the same kind of politics is involved. You'll have to investigate what kind of system you have and, what's involved in the charging of both sets, while on shore power. Many folks seem to think all motor homes are built the same with the same components. Well, that's stretching the truth a bit. As stated, there's many differences in make/year/models. This is why I try and have most of my friends LEARN all about their coaches and what makes them tick. That way, when things go wrong, they've got an idea of where to begin the investigation. Good luck.
P.S. As has been stated, a check of both the house battery voltage and chassis battery voltage, WHEN THE ENGINE IS OFF. Note the readings.
Then, start the engine, and re-check both sets of batteries. Note the voltage and compare to the first check.
Then, do the same check procedure WITHOUT SHORE POWER OR GEN POWER. Note the readings.
Then, plug into shore power, re-check both sets and note the readings. Compare to when un-plugged.