Generator Exercise & Battery Charging End Point

[bydnar]

2017 Ventana LE 4037
Magnum Inverter MS2012
Magnum AGS
Magnum Control panel
Original Interstate 6 volt GC2-XHD-UTL 232 Ah (x6)

During monthly maintenance that includes the generator exercise with load, I've always read about running for x# of hours. However, a clock does not know the state of battery charge, so I have begun the exercise of the generator by watching the charge state on the Magnum panel. Note that I do NOT have the module that reads state of charge (SOC). There are the stages of Bulk, Float and Equalization. It's rather simple that I would certainly want to get beyond the bulk and into float, but then what?

End battery charging/generator exercise:
1. When the Magnum indicates it has reached the float stage?
2. When it begins the equalization stage?

For optimal battery life, what is the best point to end the generator exercise and battery charging?

[Kahoona]

I like to have a solar panel to keep the batteries full. Then I run the generator with the AC's on until it reaches operating temp. I believe that everything will last longer this way.

[757driver]

Originally Posted by bydnar

2017 Ventana LE 4037
Magnum Inverter MS2012
Magnum AGS
Magnum Control panel
Original Interstate 6 volt GC2-XHD-UTL 232 Ah (x6)

During monthly maintenance that includes the generator exercise with load, I've always read about running for x# of hours. However, a clock does not know the state of battery charge, so I have begun the exercise of the generator by watching the charge state on the Magnum panel. Note that I do NOT have the module that reads state of charge (SOC). There are the stages of Bulk, Float and Equalization. It's rather simple that I would certainly want to get beyond the bulk and into float, but then what?

End battery charging/generator exercise:
1. When the Magnum indicates it has reached the float stage?
2. When it begins the equalization stage?

For optimal battery life, what is the best point to end the generator exercise and battery charging?

For some good information on charging your flooded batteries check out this well written document.

Simple Guide to Battery Life in your RV – Newmar Hoots

BTW your Magnum inverter has three stages of routine charging they are Bulk/Absorb/Float. Equalization is a manual cycle that is a purposeful overcharge of your batteries to try and eliminate sulfation on your lead battery plates. Lead batteries are happiest if they are left in a fully charged state.

Using a generator may not be the best or most economical way to fully charge your batteries as it could take 4-6 or more hours. I would want to get the batteries to at least the Float stage.

[Dutch Star Don]

Randy.....is your coach plugged in? If it's plugged in, don't worry about the batteries, they will stay fully charged. When you first start your generator, if your coach is not plugged in all the time, it will typically go to BULK, if not too low, will change to ABSORB and then move to FLOAT. Unless you're letting the batteries get really low between exercise of your generator, I wouldn't worry about getting to FLOAT charge. You really just need to run the generator long enough to remove any moisture that has accumulated.

In 30 years of owning coaches that had built in generators, I've never exercised any of them, primarily because we live in a dry climate. I've never had an issue.

So.....exercise your generator for moisture elimination purposes (get it warm), not to charge the batteries, unless you're really running them down while in storage.

[bydnar]

An exclusion on the question background...in storage area without plugging in. Everything off that can be off without disconnecting the batteries. In about a month, battery voltage will drop to 12.1 to 12.4 volts.

Thanks for the clarification on stage names. You are right and thanks for pointing that out.

If a solar maintainer is recommended, what size only for parasitic loss in storage? Michigan sunshine (lack)

[HavingABlast]

Randy, we have a scenario similar to yours with our 2015 Ventana in storage without electricity or solar. Once a month while in storage, I run the generator under load (one of the AC units in heat pump or cool....depending on ambient temps). I do this for about four hours. I can go to the gym, shower, then go out for lunch, then go back to the coach and shut things down. The coach never gets to “full” charge at four hours. It still reads “Float” at that point. But my end voltage registers just around 13.1v. I’ve considered hooking up one of those fold up 200 watt solar panels, but haven’t yet done so. Don’t see anyone else with them in our storage lot, so maybe they get grow legs and walk. Someday I will put some (600-800 watts) solar on the roof and not have to use the genny to keep the batts charged. Until then, I drive up and run the generator.