How is my house battery charged?

[KenMast]

Hi,

Here is a newbie question.

How is my house battery charged? Does it charge when I'm plugged into shore power? Does it charge when I'm driving? Does my chassis battery charge it?

Also, what does my generator use to start, the house battery or the chassis battery?

Thanks for any help that you can provide.

Ken

[tenbear]

I wired a trickle charger to my chassis battery. All I have to do is throw a switch and the chassis battery will be charged. Of course, I need to be connected to power, or running the genny.

[DrewE]

The Trik-L-Start is a great gizmo and easy enough to set up and forget.

If you're going to be parked for the full two months, and don't expect to drive your motorhome around with any frequency, a lower cost alternative would be a little automotive float charger such as Harbor Freight and many others sell. You would have to snake it to a 120V outlet somewhere and remember to disconnect it before driving off. For that matter, simply disconnecting the chassis battery would probably also be entirely sufficient.

By the way, there is some variation in how things are wired among various motorhomes. On my Coachmen, the connections for both the isolator and the converter are on the battery side of the main disconnect switch, which means the battery will charge regardless of its setting.

[time2roll]

Overcharging depends on the converter or inverter/charger float voltage. Post the equipment make and model for best answers. Also need to know what AGM as they have different specs. Generally in Winter it should not be an issue. Summer in Phoenix is another story.

Chassis is often not charged by the house system. Check voltage after plugging in a few days. 12.8 or less is not charging, 13.2+ is being maintained. You can add a Trik-L-Start combiner made to keep the chassis battery up if needed. Or connect the house & chassis B+ together with a jumper.

No I would not run the main engine unless you will be driving around at least 20 minutes. Not a great way to maintain charge on the battery.

[KenMast]

Hi,

Here is another question on this topic. I plan on snow birding this winter (January and February 2016) in Florida. Since I'll be on shore power for 2 months, will I have to worry about my house battery over charging? I have a deep cycle AGM no maintenence house battery.

What about my chassis battery? Should I run the engine frequently to keep the chassis battery charged?

Sorry for the dumb questions, but I'm somewhat confused about the whole electrical systems on RVs. Thanks for any help you can provide.

Ken

[wbwood]

pianotuna wrote:
Welcome to the forums.

In a Class C, the house battery charges when:

A. plugged into shore power
B. while trundling down the road (but not as much, unless the charging path has been beefed up).
C. when running the generator

The generator may be started from the chassis battery or the "house" bank, depending on the design of the RV.

I'd encourage you to add a modest solar system to maintain the house batteries while the RV is in storage.

Yes...also note that you have to have the battery disconnect switch in the "ON" position. Meaning you have ot have your batteries on for them to be charged.

[pconroy328]

naturist wrote:
Your chassis battery should NEVER charge the house battery.

He probably meant the alternator.

[naturist]

Your chassis battery should NEVER charge the house battery. If it did, you would be at risk of being able to start the engine after drawing down the house battery. Most every rig I'm familiar with has an automatic switch that disconnects the house battery from the chassis system when the engine isn't running, but you might have a manual switch, and if so, pay attention to disconnecting when you are not driving.

[rvten]

Your chassis battery only charges off the engine. Unless a device like TrikLStart was added.
The house(coach) battery's charge as stated. They will charge faster when driving fish the road.
Make sure you have you battery disconn. Switch on.

[pianotuna]

Welcome to the forums.

In a Class C, the house battery charges when:

A. plugged into shore power
B. while trundling down the road (but not as much, unless the charging path has been beefed up).
C. when running the generator

The generator may be started from the chassis battery or the "house" bank, depending on the design of the RV.

I'd encourage you to add a modest solar system to maintain the house batteries while the RV is in storage.