battery charging for a newbie

[smilinjack]

Hello All,

My wife and I are new to the GD family. We picked up a 397TH last week and are pretty excited. A couple electrical questions I want to wrap my head around. Our rig came with a generator ... Yay! But not solar at the moment. Our last rig had solar but no generator. So wrapping my head around the new process. May get solar, may not. Solar seemed to always keep the battery charged. We don't do a lot of dry camping so just looking to understand battery / generator / solar dynamics.

1. I was under the impression when the rig was plugged into the truck it would provide 12V to the rig? This was the case on the last rig. With the 397TH I had to plug in shore power to retract the slides. Being connected to the truck didn't allow me to bring the slides in. Slides moved out on rig battery but running lights ran down the battery. Plugged in the truck and no deal.
2. Am I correct that if the rig battery is low the only way to charge it is run the generator or shore power? Connecting the truck won't charge it?
3. If the rig battery is low, am I correct that I won't be able to start the generator?
4. The fridge is 12V + propane but I'm under the impression I should turn propane off while traveling? Last rig was small 12V fridge so would run when connected to the truck.
5. If I only have a single battery does it seem logical I should start the generator any time I'm in the rig with lights on or moving slides?

Thanks and God Bless,
-Sean

[Jlawles2]

smilinjack Sean, Depending on what tow rig you have will determine how much power it pushes to the camper. Also check the battery disconnect switch to see that it did not get bumped and accidentally turned off (if you can pull the red key battery is disconnected from most of the camper but not all).

I think Howard and a few others have stated that Ford's limit the 7 way plug to under 10 amps. GM is a bit better with 20 or more amps, and Dodge I do not remember anyone saying (answer may be out there).

If your battery is ran down below 12V it will take a bit to bring it back up enough to power the slides.


And welcome to the forum. Take time to read the welcome letter. https://gdrvowners.com/forum/main-fo...to-new-members

[Yoda]

Double check your disconnect switch. It should be on (red KEY cannot be removed) I say this based on you mentioning you don't have 12V unless plunged into shore power/generator. Disconnect must be on too charge batterys either from tow vehicle or shore power. At least mine was wired that way.

Trying to help

[Tom in PGH]

Another way to get power to charge the battery would be with jumper cables, from the truck to the battery. Not ideal, but it beats not having enough power to bring in the slides and head for home.

[acoleman43]

Hello All,

My wife and I are new to the GD family. We picked up a 397TH last week and are pretty excited. A couple electrical questions I want to wrap my head around. Our rig came with a generator ... Yay! But not solar at the moment. Our last rig had solar but no generator. So wrapping my head around the new process. May get solar, may not. Solar seemed to always keep the battery charged. We don't do a lot of dry camping so just looking to understand battery / generator / solar dynamics.

1. I was under the impression when the rig was plugged into the truck it would provide 12V to the rig? This was the case on the last rig. With the 397TH I had to plug in shore power to retract the slides. Being connected to the truck didn't allow me to bring the slides in. Slides moved out on rig battery but running lights ran down the battery. Plugged in the truck and no deal.
2. Am I correct that if the rig battery is low the only way to charge it is run the generator or shore power? Connecting the truck won't charge it?
3. If the rig battery is low, am I correct that I won't be able to start the generator?
4. The fridge is 12V + propane but I'm under the impression I should turn propane off while traveling? Last rig was small 12V fridge so would run when connected to the truck.
5. If I only have a single battery does it seem logical I should start the generator any time I'm in the rig with lights on or moving slides?

Thanks and God Bless,
-Sean

1- As some pointed out, it depends on the tow vehicle
2- Again, this depends on the tow vehicle. The batteries are charged via a charger. Your charger is likely an all-in-one unit....AC panel/DC panel/charger/converter. The charger uses AC power to charge your battery (via the converter). If the charger provides sufficient power (hooked up to shore power or receiving power from a generator), it will charge the batteries. Solar is not a bad option to charge/top off battery.
3- A generator has an internal combustion engine that requires a minimum amount of amps to start. If your battery (or power source being used to start the generator) does not have sufficient power, it will not start the generator....just like a car - if you're battery is "dead" your car doesn't start.
4- That's strange that you would have a 12v + propane fridge. I would think it is a 120v + propane, or 12v only. We have the 120v + propane fridge. While traveling we leave the propane on to keep the fridge running. Personally I don't see an issue with this, but it is a matter of opinion. I prefer a 12v only fridge...they perform much better and don't rely on a continued flame while running down the road at 60+ mph.
5- Generator starter has different power requirements than lights, slide motors, etc. The battery may have enough juice left to power the lights or slide motor, but not start the generator.

If you get solar to keep the batteries charged, you can go with a very small system (a single panel). The solar charge controller will keep the battery topped off with a floating charge when not in use which will prolong the useful life of the battery. When needed the solar charge controller will use a bulk charge to help charge a depleted battery. You'll have to look at cost of system to determine if it's worth the money to you.

[smilinjack]

Thanks for all the comments and helpful advice. To clarify a couple things; the fridge is 120V or propane (which requires 12V current to run the computer only as I understand it). The last rig was 12V only fridge which was super convenient. Although this fridge is almost twice as big. I also found yesterday the generator did not have enough juice to turn on BUT once I hooked up my 7-pin cable to the truck the generator started right up. It's a bit of a learning curve so I appreciate all the replys!! Driving with propane seems to be a 50/50 split on opinions. Also found some articles stating the fridge is likely to only loose 4 degrees of temp over a 6-8 driving period. That's not enough to create spoilage. Or at least if running the generator in the middle somewhere I can maybe limit the drop to 2 degrees or so. Some trial and error for sure.

We are headed out on our first week in the new rig tomorrow. Safe travels to all.

-Sean

[Jlawles2]

smilinjack Depending on how packed the fridge and freezer are along with temps inside the coach will determine how much the temperature changes during an 8 hr drive day. Also, how long will it take the unit to pull that 2 or so degrees back out. Remember these are absorption units and it takes longer to remove heat than a conventional fridge.

[Lonestar]

smilinjack I agree with Joseph, however I can tell you that with my absorption fridge even with the propane on when traveling, it is difficult on warm days to maintain the temps I would like. Also on those long days you will probably be stopping for lunch, etc, and everytime you open the door temp will rise. There is noway I could keep my loss to 4 degrees on an 80 degree day.

And yes, you will get different opinions on leaving the propane on. Honestly I've been pulling trailers for 40 years and never had an issue. YMMV.

[ncitro]

Thanks for all the comments and helpful advice. To clarify a couple things; the fridge is 120V or propane (which requires 12V current to run the computer only as I understand it). The last rig was 12V only fridge which was super convenient. Although this fridge is almost twice as big. I also found yesterday the generator did not have enough juice to turn on BUT once I hooked up my 7-pin cable to the truck the generator started right up. It's a bit of a learning curve so I appreciate all the replys!! Driving with propane seems to be a 50/50 split on opinions. Also found some articles stating the fridge is likely to only loose 4 degrees of temp over a 6-8 driving period. That's not enough to create spoilage. Or at least if running the generator in the middle somewhere I can maybe limit the drop to 2 degrees or so. Some trial and error for sure.

We are headed out on our first week in the new rig tomorrow. Safe travels to all.

-Sean

There is a post a ways back where someone did some testing of an absorption fridge with a logging thermometer. I forget the exact results but the gist was you could not go very long (maybe only an hour or two) before the temperature rose to unacceptable levels. I would plan on either running it on propane, or off on an inverter. Be warned the inverter path has led several of us to replace it with a residential fridge for improved cooling and power draw lol.

[Cate&Rob]

smilinjack

See this thread, particularly the attachment to post 1, before deciding to leave the fridge off while travelling.
https://gdrvowners.com/forum/operati...d-temperatures

Rob

[smilinjack]

Thanks for the feedback. Didn’t realize a low battery would take a bit when plugged into the tow vehicle. Makes a TON of sense. Our first trip without propane on with the fridge left things a bit warm. In considering the argument behind turning propane off is to avoid an explosion in a major wreck with a cut line. I run Gas Stop valves on my propane tank just for this purpose so this outing (driving today 10/8) we left the propane on and things remained cold without worry.

-Sean & Steph

[ThePowells]

smilinjack Welcome to the family and the forum!
Please excuse my being late to welcome you but I haven’t been able keep up with anything but life for the last month.