Have MH in storage with batteries disconnected. Used switch that is in coach. Anyway, when I go out to MH for whatever reason I always switch batteries back on and check charge. This last time it showed that they were 3/4 charged. Due to some health issues coach has been stored for about the past 4 months.Was wondering if anyone has guideline on how long I should run the generator to bring batteries back up to charge? Do not have access to electric plug-in so thought running the generator would be the way to do it.All help appreciated.

You are going to have to help us a little. What kind,size of battery bank do you have and tell us what you have for a converter. Than, I would think that someone could give you an idea. Might be longer than you think or hope for. If you are looking for a full charge that could be an all day job. Give us more information on what you have.

You're disconnect switch doesn't disconnect everything, you should really be disconnecting the main battery cables so that you don't have this problem.As for how long, I would expect your Kountry Star to have some sort of panel that tells you what the amp draw is when the generator is running. With everything else turned off (not drawing power from the generator or batteries) you should be charged when the amp draw on the generator drops to 3 - 4 amps.Bill

IF you disconnect at the batteries then two hours should bring them up. Shutting the switch off by the door often leaves some loads on the batteries.

Run the gennie at least an hour, with a space heater running (1/2 load). This will recharge batteries and exercise your Gennie (important).

100% tip top charge will generally take 6 to 10 hours. Best to be plugged in or 100+ watts of solar. Will also depend on the charging system voltage. if you are charging at just 13.6 normal mode it can take 24 to 48 hours on generator.Good to just take it out camping even if just one night. Can you start the generator and run it overnight?

Run generator to charge batteries (how long) | Good Sam Community

21 Replies

Canadian_Rainbi
Explorer
Dec 15, 2015
rvten wrote:
Your batteries will charge faster using the chassis charge system. Means you have to run your engine.

Not on my rig. The inverter/charger will charge at 100 Amps
turnersteve
Explorer
Dec 14, 2015
pianotuna wrote:
Shore power or solar are the only two economical ways of getting a battery bank to 100% state of charge.

I agree, my solar system keeps my house and starting batteries fully charged without me having to do anything.
pianotuna
Nomad III
Dec 14, 2015
It may take up to 168 hours to fully 100% charge a battery bank. It depends on the charging voltage, and many other variables. Only shore power and solar will do the deed economically. For generator charging 50 to 90 is about as good as it is going to get.

At 85% of fully charged the battery acceptance rate is about 12.5 amps per 100 amp-hours of storage. That translates to 150 watts of solar per 100 amp hours of storage.
jerseyjim
Explorer
Dec 14, 2015
When in "storage" for at least 3 months, I start the engine AND the generator every 2 weeks. Leave them run for about 1/2 hour. Works for me.
wolfe10
Explorer
Dec 13, 2015
fitznj wrote:
Marine/deep-cycle batteries like to be charged slowly over longer time periods as opposed to car batteries- which can tolerate a quick/high current.

I've found that when camping, I need about 6 hours of generator per day to bring the batteries up to "full" charge. I have a voltmeter connected directly to the battery - so can monitor them. I now have a ~150W solar panel connected to the batteries while in storage and the voltage is consistently at 13.2V.

Gerry

Gerry,

Absolutely true a couple of decades ago. And is still true with "stupid" converters. But, with modern smart chargers and smart inverter/chargers, charging time is shortened. That is because charge voltage in BULK phase is quite a lot higher than the "stupid" converter put out.

Since we still don't know what charger the OP has, you may be exactly correct.
fitznj
Explorer
Dec 13, 2015
Marine/deep-cycle batteries like to be charged slowly over longer time periods as opposed to car batteries- which can tolerate a quick/high current.

I've found that when camping, I need about 6 hours of generator per day to bring the batteries up to "full" charge. I have a voltmeter connected directly to the battery - so can monitor them. I now have a ~150W solar panel connected to the batteries while in storage and the voltage is consistently at 13.2V.

Gerry
bluwtr49
Explorer II
Dec 13, 2015
I've found that running the genny until the inverter shows the bulk charge is complete jams in the most juice in the shortest period of time.

This approach worked well for me on our boats and with the MH.
CA_Traveler
Explorer III
Dec 13, 2015
rvten wrote:
Your batteries will charge faster using the chassis charge system. Means you have to run your engine.
That is not a given and depends upon a lot of factors.

If you're going to run the engine then drive the rig for about 20 miles to get the oil warm and eliminate moisture from the engine.
RayChez
Explorer
Dec 13, 2015
If your house batteries are 3/4 full right now, IF you start your generator, it will take about two hours to fully charge IF not less.
donfrump
Explorer
Dec 13, 2015
rvten wrote:
Your batteries will charge faster using the chassis charge system. Means you have to run your engine.

that would depend on what size(output) the inverter/converter system is in the Diesel pusher the op owns
One thing the OP could do would be plug in a 100 amp charger and charge the batterys using a stand alone charger
that may be quicker than the house converter/charger BUT depends on the size of the MH charging unit