Quote:
Originally Posted by liveaboard74
Have several boats thought about installing a marine battery and trickle charger . I have three batterys in there now. Gas motor. v10.
Found out today you have to flip the switch on the dash to Aux to get the generator to fire. Yes sir this is a whole different world than slide in campers.  |
This may be a time to get into some of the small points as hitting the aux switch is not normal. But then there may be small points to help, also.
Small rundown on the aux switch may help. The switch is a momentarty switch, meaning it stays operated only as long as we push the switch. that's one that is often missed but leads to more confsuion.
When we press (and hold) the aux or boost switch, it closes a big solenoid on the older RV and that solenoid has two functions.
The function when we push the switch is to connect both coach and chassis battery sets together to give a weak chassis battery a "boost" to let us get by if we happen to run the chassis battery down.
Part of the confusion is the changing names for the switch, aux is meant to imply the coach batteries which used to be called auxilery batteries! Boost seems to be a better name for the switch!
But the second thing this mode solenoid, or BIM on newer RV, does is connect the batteries together when the ignition is on! This lets the coach batteries get some small amount of charge as we drive. Not usually enough to get back to full power if they are really down as it may take 6 hours or more for full charge, but "some".
That second function can get folks fooled into thinking they can go home and put a charger from the converter on the coach battteries when plugged in and since both are connected both sets are maintained. WRONG!
Unless there is some other connection or system in place, the two are seperated when we turn off the engine and that can leave the chassis battery going dead when we store the RV!
But when the generator has to have the aux switch pushed, it shows the chassis engine is not quite up to the job and may be a bit suspect.
But one thing to keep in mind is the way we can get the best chance at starting the generator if we do things in the right order.
The RV engine is always more likely to start quicker and easier without as much cranking. One reason for this is that we may have to crank the generator because the fuel has run back away and it takes longer if it has not been started recently.
So if we want to have the best shot at starting the generator, we can start the RV engine first! That not only ties both battery sets together with engine running but it also puts the engine alternator online to really give that generator starter a kick to get going!
Any electrical stuff that draws lots of power like generator, jacks, slides, will operate better and last longer if we give them good voltage by starting the engine first.
A small point often missed is the way low voltage can harm electrical things as it seem backwards. We hear about things burning out and people think it was too high voltage when it is much more commonly low voltage!
Low voltage takes longer to get a motor to turn. During that slow start, much more current is drawn through the motor windings and that heat is what "burns up" the motor!
High voltage like lightning strikes can burn up motors but starting them every time with low voltage is much more common. It sneaks up and we may never see it because there is not a big flash and boom to get our attention. The motors just slowly die!
When needing to use the aux, it is saying the chassis battery is not quite as good as it might be, so some checking may head off a failure OR we can start the engine first and avoid the question for some time.
Possibly the chassis battery was just a bit run down and the generator needs more than normal cranking?
Like any old cat, the one that lasts longer is the one that stays alert!
Linear Mode
