Battery & electrical questions
I have a 2014 Coachmen 21QB on a Chevy 4500 chassis, with an Onan 4KW generator. *Does the generator have its own starting battery? If so, how is this battery charged? Or does the generator crank...
Forum Discussion
Based on my 1998 Coachmen Santara...I'm guessing your motorhome is similar.
The generator starts off the house battery in my motorhome. It's not as silly as it sounds because the generator requires some 12V power while it's running, and if that's from the house system it comes from the converter rather than running down the chassis battery. The generator doesn't have any 12V charger built-in to it directly. (I think a 12V charger is an option that can be had with the Onan generator, but it's very rare in RV applications since you need the converter anyway.)
No, not as from the factory; neither does the converter when plugged into shore power, since it's the same thing. A Trik-L-Start is one way to get this, or you can just connect up and plug in a small battery charger.
Yes, and on mine pretty well--at least well enough to have a nicely recharged house battery after a day of driving.
The battery isolator is likely a solenoid, which is active whenever the engine is running or the emergency start switch is pressed. When not active, the two batteries are entirely separated and isolated. When active, they're tied together.
Do not confuse this with the house battery disconnect switch, which is a separate thing that disconnects most of the house circuits from the house battery. Exactly what is disconnected varies from RV to RV; on mine, as built by the factory, the disconnect is between the house battery and the 12V distribution panel, and the only things that are not disconnected are the generator (presumably because the current required when starting is more than is wise to put through the disconnect switch), the connection to the battery isolator, the converter, the dash radio memory line, and the power for the (manually-controlled) entry step.
No
If it's connected to the chassis battery more or less directly, it's probably to protect the wire used for charging the house battery and for the emergency start. The other end of the wire connects to the battery isolator solenoid, which in my case is next to the house battery, along with it's main fuse and a few self-resetting circuit breakers and so forth.
coolmom42 wrote:
*Does the generator have its own starting battery? If so, how is this battery charged? Or does the generator crank off the chassis battery? (I'm assuming it doesn't crank off the house battery, as that would kind of defeat the point of having a generator.)
The generator starts off the house battery in my motorhome. It's not as silly as it sounds because the generator requires some 12V power while it's running, and if that's from the house system it comes from the converter rather than running down the chassis battery. The generator doesn't have any 12V charger built-in to it directly. (I think a 12V charger is an option that can be had with the Onan generator, but it's very rare in RV applications since you need the converter anyway.)
coolmom42 wrote:
*Does the generator charge the chassis battery?
No, not as from the factory; neither does the converter when plugged into shore power, since it's the same thing. A Trik-L-Start is one way to get this, or you can just connect up and plug in a small battery charger.
coolmom42 wrote:
*Does the chassis alternator charge the house battery? If so, how well?
Yes, and on mine pretty well--at least well enough to have a nicely recharged house battery after a day of driving.
coolmom42 wrote:
*Does the battery isolator switch completely isolate the house battery and chassis battery from each other?
The battery isolator is likely a solenoid, which is active whenever the engine is running or the emergency start switch is pressed. When not active, the two batteries are entirely separated and isolated. When active, they're tied together.
Do not confuse this with the house battery disconnect switch, which is a separate thing that disconnects most of the house circuits from the house battery. Exactly what is disconnected varies from RV to RV; on mine, as built by the factory, the disconnect is between the house battery and the 12V distribution panel, and the only things that are not disconnected are the generator (presumably because the current required when starting is more than is wise to put through the disconnect switch), the connection to the battery isolator, the converter, the dash radio memory line, and the power for the (manually-controlled) entry step.
coolmom42 wrote:
*Does the converter charge the chassis battery when the RV is plugged into shore power?
No
coolmom42 wrote:
*On the side of the engine compartment, there is a 200 amp fuse. What is this for?
If it's connected to the chassis battery more or less directly, it's probably to protect the wire used for charging the house battery and for the emergency start. The other end of the wire connects to the battery isolator solenoid, which in my case is next to the house battery, along with it's main fuse and a few self-resetting circuit breakers and so forth.
