Community Forums

BrewdogMN · 10-04-2016, 10:07 PM

Does anyone know if your generator starts from your coach batteries or your chassis batteries? Also if you run your generator does it charge your chassis batteries? Thanks

Dennis4809 · 10-04-2016, 10:12 PM

Mine starts from the coach batteries. Believe most are that way but then there's always an exception.

jharrell · 10-04-2016, 10:27 PM

Mine is started from house batteries, I might move it over to chassis though, seems to make more sense.

Mine did not charge chassis from generator or shore, so I added a Amp-L-Start to fix that. Some coaches have isolator that will charge chassis from gen standard. My isolator relay only connects when ignition is on allowing alternator to charge house

"007" · 10-04-2016, 10:36 PM

Welcome to irv2.
A DP the Gen starts from your chassis batteries, a gas coach it starts from your house batteries.
Your Gen will charge all your batteries with the help of your converter and the
BIRD or B.I.M. SYSTEM to monitor the charging.
The Gen may have a AGS system to start it when your batteries read low, you can find info on that in QT's # 3.
If you have shore power available the batteries will be charged also plus your alternator when you are driving controlled by your charging system.
All the links below in my signature will have info for your Newmar.
Enjoy and safe travels.

BrewdogMN · 10-06-2016, 02:55 PM

Thanks 007. Very complete answer. I appreciate the Newmar information as well. I am learning a lot right now. Owners manual is bit on the shy side. Previous owner left a lot of information and I am currently digesting it and all online information. Quite a learning curve going from a camper to an RV and gas to DP. By the way I have been on a lot of pages of this forum and you are like the energizer bunny and everywhere. You are very helpful and clearly knowledgeable. Thanks for your effort it is greatly appreciated.

Smitty77 · 10-06-2016, 05:01 PM

Also remember that in most coaches, you have the Auxiliary Battery Switch available to help out.

If your generator and or engine, will not turnover, find and hold your Auxiliary Battery Switch (Called by different names, but basically a switch that links house and chassis together.) for a good 30 seconds at least. Then I always recommend starting the Generator first. (Even if all you want to do is drive your RV. Get the Generator fired up, as it is an easier load on the weak batteries. And the Generator will also usually provide charging to you batteries.)

You will find that many, myself included, have also been able to travel for long periods with a dead or weak alternator, by firing up the generator.

And yeah, "007" does a pretty good job on his info sharing. Not quite as long winded as a gent with he handle Smitty, but you know - he has only 22K+ posts under his belt - so he's still learning to be as confusing, and less crisp in his posts...

I can assure you, it takes time to learn how to ramble on as long as I do... Let me tell you about the time...

Best of luck to you, enjoy your rig!
Smitty

canman001 · 10-06-2016, 05:11 PM

There are some brands that supply a stand alone battery for the generator. This battery is kept charged either by shore power or alternator.

nothermark · 10-06-2016, 05:43 PM

FWIW most gas MH's don't have a BIRD or BIM. It's worth checking yours. Assuming it's a Newmar it probably does but you know what assume means.

If your generator is on the house (chassis) batteries then if it won't start you can start the main engine and use it to charge the house batteries a bit to start the generator while keeping a live engine battery. If you switch to start off the engine battery and have a starting problem with the generator you end up with all the batteries flat. Something I keep in mind, YMMV.

Since I know my house system does not charge the engine battery I keep a small charger (6 amp) in my tool stash. Handy if either the towed or the engine battery needs a boost from sitting too long. A couple of hours charging is usually enough to get things happy.

BrewdogMN · 10-06-2016, 06:55 PM

I just had a weird thought and thought I would run it by the "expert thinkers". Would it be possible to jump your generator? Since one is usually backed into a spot and getting a vehicle close enough to jump would be difficult. I haven't looked at the wiring on the generator but I thought hmm maybe. Would not do it without a complete analysis and probably run it passed Onan.

nothermark · 10-06-2016, 07:18 PM

The short answer is yes. The long answer is that whatever battery bank it is connected to will be what you connect to so you will be bulk charging that system unless you disconnect the generator from it's power lead and put in a different connection. Probably more work than it is worth. A much easier answer is probably to jumper to a running vehicle and let it bulk charge the low battery for a few minutes then try to start either the engine or generator. Once you have either one running you can charge all the batteries with the built in systems.

FWIW there are two different scenario's for flat batteries.

If they are just low enough to not start but will turn over the device you want to start then it probably does not take a lot to bulk charge from another vehicle then start while still connected and let the source vehicle run a bit after being disconnected. Better yet take it for a ride.

If the batteries are run really low cells start to collapse electrically. Charging current goes way up in an uncontrolled situation. Your jumper cables can become the limiting resistor thus getting very hot. Your internal charging system may or may not be able to charge up as it may fault from excessive current instead. That situation can be handled but it takes time and the right tools. Maybe a jumper cable works and maybe you fry everything.

rsn48 · 10-07-2016, 08:37 PM

I successfully killed my house batteries through stupidity. When I tried the generator - nothing. I then started the motorhome engine and let it go for about 20 minutes and thus got the generator going.

PS: when you are boondocking, don't leave a large window open while your furnace is running and eating up all your power, or you could wake up with...... just saying.

PPS: Winnebago Adventurer gas 1994.