Another Battery Charging Question

[gypsmjim]

The new 2015 Jayco has a 3 stage charger in the WFCO system. Experimenting with that vs. different auxilliary chargers has shown it actually works the best. We boondock 100%, so using my Yami generator is my only option to keep the battery charged.

My question is....if I run the generator with the shore cable attached, can I also use the generator's built in 12 v battery generator as well, at the same time? If so, will that enhance the charge rate?

A second scenario is to connect the shore cable and run a smart charger off the generator at the same time instead of the generator's 12 v output. Is that feasible?

[Mustang65]

FIRST, I would check to see the specifications on the generators 12VDC output. How many amps can it produce? How does it determine what charge voltage is/should be (does it have a 12 volt charge controller), or is it a FIXED output voltage? If it is fixed does it have an automatic shutoff (timer), so as not to overcharge the batteries? My home generator's 12 VDC output is 14 volts, and there is no smart circuitry to controll the charge process, so if I am not monitoring it I could cook the batteries ($$$).

It will be one or the other that will win the charging war. If you connected your shore power to your generator and ran it with out the 12VDC generator output, your TT's battery charge controller would produce the necessary volts/amps needed to charge the battery, based on the state of your battery. This process may take a little longer because it follows the proper algorithms to insure a safe charge rate.
The battery charge controller in our Eagle is rated at 45 amps, but since we use solar, it has been disconnected since going solar almost 2 years ago.

If you you connect your batteries directly to the 12 VDC output of your generator, without shore power, it will charge your batteries up to the max amps your generator will produce.

If you you connect your shore power and you also connect to your generators (without a charge controller) 12VDC output, the TT's battery charge controller will probably see a higher voltage at the batteries (14VDC?? from your 12VDC generator output) and decide that the batteries do not need a charge and will not charge your batteries. The your generator will be the only charging device.

If your generator has a 12VDC charge controller, they will both work together and seek out the proper voltage/amps.

As far as doing any harm, before I rewired my TT's battery charge controller to it own AC breaker, the solar charge controller and the TT's charge controller worked together while connected to shore power. No problems!

Just my thoughts,
Don

[Big Sky]

I'm confused on this. I would think your 3-stage charger is going to give you the best performance with recharging your batteries, regardless of the shore power source. I would also think that if you had your generator 12V charger connected to the batteries it would mess with the reading being sent back to your 3-stage charger and not allow it to correctly charge. Others on this forum are electrical gurus but my bet is stay with the 3-stage charger, without trying to augment the charge.

[tnchuck100]

Most generator 12VDC charge output is rather crude. Usually are 8 amps or so. Not regulated. Not "smart". Your 3-stage converter/charger will do a far better job of charging the battery.

[Mustang65]

Originally Posted by Big Sky

I'm confused on this. I would think your 3-stage charger is going to give you the best performance with recharging your batteries, regardless of the shore power source. I would also think that if you had your generator 12V charger connected to the batteries it would mess with the reading being sent back to your 3-stage charger and not allow it to correctly charge. Others on this forum are electrical gurus but my bet is stay with the 3-stage charger, without trying to augment the charge.

BigSky you are correct... but the issue is not the shore power source, it is using the TT's charge controller at the same time charging the batteries with the 12 VDC output of the generator. Like plugging the TT's shore power into the generators 120VAC and connecting the batteries to the generators 12VDC output at the same time.

As I mentioned if your generator does NOT have a smart controller it will mess with the TT's 3 stage charger's microprocessor's ability read the batteries ACTUAL voltage to charge the batteries according to how it is programmed for "This process may take a little longer, because it follows the proper algorithms to insure a safe charge rate"..

Where as the generator (without a smart controller as most do not have) will constantly pump out a higher voltage/amps and charge the battery at a faster rate, but can heat up the battery during charging. The life of the battery will be shortened by constantly using this process.

With today's smart charge controllers installed in TT's, they are the best for giving your battery a longer life.

If you have SOLAR and not using a generator, believe it or not the battery manufactures are recommending 2 stage charging, Bulk and Float as the sun is only producing power about 4 to 5 hours a day.

Don

[OnTheGo]

gypsmjim, It sounds to like your OK with WFCO's 3 stage charger, but you want to do something in addition to charge faster. If that's where your headed with this thread, I don't know to accomplish that, but I can offer a solution we use when boondocking.

We travel with a 2nd battery (AGM so were not dealing with acid and fumes) and a NOCO 26A smart charger. We don't parallel them. We use one while the other one charges. It's extra expense and work, but if you can get by with the draw from a single battery it's a workable solution.

Edit: ... forgot to mention - The NOCO charger does a better job than the built-in on the Honda generator.

[gypsmjim]

Again, Thanks to all for the comments. At present, I AM satisfied with the existing charger, but its true I am just looking to get the battery up to 100% a little faster. We only use the trailer on weekends, and sometimes a couple weeks apart. I'm finding that there just isn't enough time to giterdone. We leave to go home about 4 PM Sunday and by then the battery is still maybe only 95%. I guess I could run the generator all day long but I'm trying to avoid that if possible.

Next weekend will be the last outing of the year, and that's only if I can get thru. As I write this the weather is good at home as well as at the camp, but there is 3 feet of snow between us and its coming down 3" an hour. I plan to bring the battery home for Winter and then I'll get a better idea of its condition. It was drained pretty low a couple of times as we were learning how the new Jayco works.

Thanks again...

[Mustang65]

Just a thought... for next year you may want to look at a small SOLAR panel system (100 watt - 150 watts) to mount on your trailer roof. Since you pretty much just use the trailer over the weekends, the solar panel(s) would have you up to 100% for your next weekend. Your generator time would be reduced also.

You could mount the panels on rails and for the winter, and just remove the solar panels until spring.

Just my thoughts,

Don

[gypsmjim]

Originally Posted by Mustang65

Just a thought... for next year you may want to look at a small SOLAR panel system (100 watt - 150 watts) to mount on your trailer roof. Since you pretty much just use the trailer over the weekends, the solar panel(s) would have you up to 100% for your next weekend. Your generator time would be reduced also.

You could mount the panels on rails and for the winter, and just remove the solar panels until spring.

Just my thoughts,

Don

Actually, that IS my plan. I have a small shed right next to the trailer - the panel will go on that roof so I don't have to disturb the rubber roof on the trailer. The shed roof is angled right toward the sun so I figure that's better anyway.

I hadn't thought of taking it down in Winter - is there a good reason to do that, as opposed to leaving it up with the charge controller turned off all Winter?

[Mustang65]

Originally Posted by gypsmjim

I hadn't thought of taking it down in Winter - is there a good reason to do that, as opposed to leaving it up with the charge controller turned off all Winter?

No reason other than security..
Don