Reply
 
Thread Tools Display Modes
 
Old 06-13-2020, 04:15 PM   #1
Mini-Skoolie
 
Join Date: Sep 2019
Location: Melbourne, FL
Posts: 52
Year: 2005
Coachwork: Thomas
Chassis: Saf-T-Liner MVP EF
Engine: Cat C7
Rated Cap: 29 (Perimeter Seating)
generator starting battery?

I didnt have much luck searching this... which battery do most of you use to start the genny? Is it dedicated?
stlthe is offline   Reply With Quote
Old 06-13-2020, 05:27 PM   #2
Bus Crazy
 
Join Date: Nov 2016
Posts: 1,655
To me would be silly, just another point of failure.

Such a trivial service / duty cycle, does not matter if you tap into the main engine Starter batt (which yes should usually be dedicated)

or into a decent sized House bank, if that is much closer.

Obviously long enough jumper cabling for backup, or a lithium jumpstarter pack would be wise just in case.
john61ct is offline   Reply With Quote
Old 06-15-2020, 03:13 PM   #3
Bus Nut
 
Join Date: Jan 2020
Location: Wild Wild West
Posts: 409
Year: 1999
Coachwork: Blue Bird
Chassis: TC RE
Engine: 8.3 Cummins MD3060
Rated Cap: 84
The only concern with having a dedicated battery is making sure it has some source for being charged. I believe most generators that have a starter motor probably have some source to recharge their own battery. If not, you will need to tie into the main batteries to power the starter, or run a charging wire to the generator battery from the bus system.
JackE is offline   Reply With Quote
Old 06-15-2020, 05:14 PM   #4
Bus Crazy
 
Ronnie's Avatar
 
Join Date: Oct 2017
Location: Virginia
Posts: 1,575
Year: 1971
Coachwork: Wayne
Chassis: International Loadstar 1700
Engine: 345 international V-8
Many Onan rv generators do not charge their own battery. Typical rv useage has it run off the house batteries, and the batteries are charged by a power supply that feeds all 12volt functions in the rv, and keeps the house batteries charged.

For me I run it off the house batteries, and my solar panels keep them charged.
Ronnie is offline   Reply With Quote
Old 06-15-2020, 06:24 PM   #5
Bus Crazy
 
Join Date: Jun 2013
Location: Picton,Ont, Can.
Posts: 1,956
Year: 1997
Coachwork: Bluebird
Chassis: GMC
Engine: Cat 3116
Rated Cap: 72
If simplicity is desired, mount a lawn tractor battery in near proximity and charge as necessary with a regular charger. Saves headaches and downsizes wire size. Just ground genny frame to neg terminal of battery.
A cheap, simple installation.


John
__________________
Question everything!
BlackJohn is offline   Reply With Quote
Old 06-15-2020, 08:32 PM   #6
Bus Crazy
 
turf's Avatar
 
Join Date: Apr 2013
Location: Colorado
Posts: 1,617
Year: 1993
Coachwork: bluebird
Engine: 5.9 Cummins, Allison AT1545
Rated Cap: 2
i'll be odd man out.

my bus has a 12kw diesel generator, it came that way from the factory - its a former bookmobile. there is no other option to start the generator other than battery start. the generator does have its own battery and somehow keeps it charged however, im not sure if its through the gen head or an alternator.

the bus has its own starting batteries - i have 2 group 31s for that. in the same box i have a 3rd grp 31 for the generator. the bus ignition separates the 2 different systems when the bus is off and joins them together when the bus is on.

im sure i could put a smaller battery on the gen, but keeping them all the same in the battery box just makes life easier.

another point of failure? no
with the separator, the bus charges the gen battery, and with the ignition on the gen can charge the bus battery.
its a built in battery charger.

since those 3 batteries tend to my mechanical needs, i have added a 4 battery bank for my house 12v loads. i keep 7 batteries on board.
__________________
.
Turfmobile Build Thread
turf is offline   Reply With Quote
Old 06-16-2020, 11:07 AM   #7
Bus Geek
 
ol trunt's Avatar
 
Join Date: Apr 2012
Location: So Cal
Posts: 2,716
Year: 1935
Coachwork: Superior
Chassis: Chevy
Engine: 317 ci/tid / Isuzu
Turf, since you've taken odd man out I'll just have to go with Dr. Bazzaaro.

My Yamaha inverter genny came with a self recharging jump box size starting battery. Since I put the entire genny (except muffler) in a slide out quiet drawer both the genny start battery and the pull cord start became not readily accessible should the battery fail. Since I had a group 27 battery in place to power the compressor for the pneumatic door and air over hydraulic toad brakes I hooked the genny to the G27 and did away with the tiny start battery. The G27 can be charged by the genny or the bus alternator depending on switch position. By accident of design rather than plan, the genny can charge the compressor G27 battery which can charge the start batteries. Nevertheless I do carry a hefty jumper cable in case I need to tie something to the bus.
Jack
ol trunt is offline   Reply With Quote
Old 06-16-2020, 02:04 PM   #8
Bus Crazy
 
Join Date: May 2014
Location: West Ohio
Posts: 1,696
Year: 1984
Coachwork: Bluebird
Chassis: International 1753
Engine: 6.9 International
Rated Cap: 65
I'm like turf.

I don't have a house bank(yet), so the generator is hooked to the same pair of group 31 starting batteries the bus uses.

My generator has a 60 amp alternator on it. Running the generator it uses 20-30 amps, so I can charge 30 or so amps if desired. I don't want to do that because alternators aren't meant to be ran full bore for hours at a time. If this alternator ever craps out, I'll likely go custom and install a larger (100+ amp) alternator in it's place.

Eventually, I'll get a dc fridge/appliances and then build a house bank/solar setup. I'll still likely run the genny off the bus batteries though, and then have a 120vac charger charge the house bank when the generator runs.

They're are many different ways to skin this cat, best bet is to research and figure out which one would work best for you.
__________________
The Silver Bullet https://www.skoolie.net/forums/f11/p...llet-9266.html
Booyah45828 is offline   Reply With Quote
Old 06-16-2020, 08:30 PM   #9
Bus Crazy
 
Join Date: Nov 2016
Posts: 1,655
All of those solutions work fine.

My principle is, no less than two total banks for some level of redundancy.

Going higher adds complexity, more to monitor / test / replace, but that is just a judgment call.

Lots of *starter* batts is NBD, but only one House bank, that is a stronger rule of thumb.
john61ct is offline   Reply With Quote
Old 06-16-2020, 08:38 PM   #10
Mini-Skoolie
 
Join Date: Sep 2019
Location: Melbourne, FL
Posts: 52
Year: 2005
Coachwork: Thomas
Chassis: Saf-T-Liner MVP EF
Engine: Cat C7
Rated Cap: 29 (Perimeter Seating)
Thanks for all the input!

I think i'll forego the dedicated battery and connect in to the starting group with an appropriately sized cable...can i just ground the negative contact solidly to the frame or do i need to run a negative cable up to the starting batt?
stlthe is offline   Reply With Quote
Old 06-17-2020, 07:18 AM   #11
Bus Nut
 
Join Date: Jan 2020
Location: Wild Wild West
Posts: 409
Year: 1999
Coachwork: Blue Bird
Chassis: TC RE
Engine: 8.3 Cummins MD3060
Rated Cap: 84
To the frame is fine, but use the same gauge wire as you do for the positive side.
JackE is offline   Reply With Quote
Old 06-17-2020, 08:32 AM   #12
Bus Geek
 
EastCoastCB's Avatar
 
Join Date: Sep 2014
Location: Eustis FLORIDA
Posts: 21,998
Year: 1999
Coachwork: Thomas
Chassis: Freighliner FS65
Engine: Cat 3126
Rated Cap: 15
Quote:
Originally Posted by turf View Post
i'll be odd man out.

my bus has a 12kw diesel generator, it came that way from the factory - its a former bookmobile. there is no other option to start the generator other than battery start. the generator does have its own battery and somehow keeps it charged however, im not sure if its through the gen head or an alternator.

the bus has its own starting batteries - i have 2 group 31s for that. in the same box i have a 3rd grp 31 for the generator. the bus ignition separates the 2 different systems when the bus is off and joins them together when the bus is on.

im sure i could put a smaller battery on the gen, but keeping them all the same in the battery box just makes life easier.

another point of failure? no
with the separator, the bus charges the gen battery, and with the ignition on the gen can charge the bus battery.
its a built in battery charger.

since those 3 batteries tend to my mechanical needs, i have added a 4 battery bank for my house 12v loads. i keep 7 batteries on board.
Hey man- how ya doin? Nice to see ya on here again!
__________________
.
Roll Your Own Build Thread
EastCoastCB is offline   Reply With Quote
Old 06-25-2020, 05:48 PM   #13
Bus Nut
 
Join Date: Feb 2018
Location: Golden Valley AZ
Posts: 590
Year: 1993
Chassis: ThomasBuilt 30'
Engine: need someone to tell me
Rated Cap: me + 1
Quote:
Originally Posted by Ronnie View Post
Many Onan rv generators do not charge their own battery. Typical rv useage has it run off the house batteries, and the batteries are charged by a power supply that feeds all 12volt functions in the rv, and keeps the house batteries charged.

For me I run it off the house batteries, and my solar panels keep them charged.

Stupid question - so cloudy that house battery goes down too low and you need to start genny... what do you do?
kidharris is offline   Reply With Quote
Old 06-25-2020, 06:17 PM   #14
Bus Crazy
 
Ronnie's Avatar
 
Join Date: Oct 2017
Location: Virginia
Posts: 1,575
Year: 1971
Coachwork: Wayne
Chassis: International Loadstar 1700
Engine: 345 international V-8
Quote:
Originally Posted by kidharris View Post
Stupid question - so cloudy that house battery goes down too low and you need to start genny... what do you do?
Monitor my battery levels and not let them get to low to start. I could put a low battery alarm on it too, but have not.

Deeply discharging batteries is not good for them anyway, so monitoring is a normal daily check anyway. More often on cloudy days. I did run them down more then I would have liked last fall when my boat battery got low and I charged it from the bus, two days in a row and we had more cloudy days then expected. My inverter was not happy but I was still able to start the bus engine when it was time to leave. So I do know my minimum threshold for battery level is still enough to start.
Ronnie is offline   Reply With Quote
Old 06-26-2020, 08:20 AM   #15
Bus Crazy
 
Join Date: May 2014
Location: West Ohio
Posts: 1,696
Year: 1984
Coachwork: Bluebird
Chassis: International 1753
Engine: 6.9 International
Rated Cap: 65
Quote:
Originally Posted by kidharris View Post
Stupid question - so cloudy that house battery goes down too low and you need to start genny... what do you do?
I thought of that too. I was considering a remote car starter because I know certain ones have a low voltage feature that will start the vehicle if battery voltage goes below a certain threshold.

Then I found this, and am really liking it's features.

https://www.ebay.com/itm/Low-Battery...-/222519473437

It has a low voltage on and high voltage off setting, an engine pre-heat controller for glow plugs(what my generator has) and a few safety features(low oil pressure, high coolant temp, etc.) to prevent engine damage.

However, I'm really liking it's auto functions. My generator has glow plugs on a push button. If they're needed to start, you hold the button in for a few seconds and you're good to go. It works for people who understand engines and when glow plugs are needed, but for those that don't this seems to be a simpler approach.

They can flip the switch and let it do it's thing. Did I say that I'm really liking this device?
__________________
The Silver Bullet https://www.skoolie.net/forums/f11/p...llet-9266.html
Booyah45828 is offline   Reply With Quote
Old 06-26-2020, 11:22 AM   #16
Bus Crazy
 
Join Date: Nov 2016
Posts: 1,655
Starter group must get automatically isolated from House loads

ideally soon as there is no charge source active

Or at least at a voltage well above what is needed to guarantee easy starting.

In which case an adjustable LVC "battery protector" is better than one with a fixed voltage
john61ct is offline   Reply With Quote
Old 06-26-2020, 11:28 AM   #17
Bus Crazy
 
Ronnie's Avatar
 
Join Date: Oct 2017
Location: Virginia
Posts: 1,575
Year: 1971
Coachwork: Wayne
Chassis: International Loadstar 1700
Engine: 345 international V-8
Quote:
Originally Posted by Booyah45828 View Post
I thought of that too. I was considering a remote car starter because I know certain ones have a low voltage feature that will start the vehicle if battery voltage goes below a certain threshold.

Then I found this, and am really liking it's features.

https://www.ebay.com/itm/Low-Battery...-/222519473437

It has a low voltage on and high voltage off setting, an engine pre-heat controller for glow plugs(what my generator has) and a few safety features(low oil pressure, high coolant temp, etc.) to prevent engine damage.

However, I'm really liking it's auto functions. My generator has glow plugs on a push button. If they're needed to start, you hold the button in for a few seconds and you're good to go. It works for people who understand engines and when glow plugs are needed, but for those that don't this seems to be a simpler approach.

They can flip the switch and let it do it's thing. Did I say that I'm really liking this device?

This looks like a really good idea. My generator does not charge the batteries so not for me, but for those who have a generator that charges, or a charge controller that runs off 110 a/c then it would be great.

I am set up for the time being with solar, or running the bus engine to charge batteries. I would not want auto start on the bus engine, that could be interesting if it started in gear(manual trans)....
Ronnie is offline   Reply With Quote
Old 06-26-2020, 01:23 PM   #18
Bus Crazy
 
Join Date: May 2014
Location: West Ohio
Posts: 1,696
Year: 1984
Coachwork: Bluebird
Chassis: International 1753
Engine: 6.9 International
Rated Cap: 65
Yeah, I wouldn't want it on the bus engine. Definitely on the generator.

I wonder how hard it would be to rig up an onan to charge it's batteries. I know they make small alternators that work off the magnets in the flywheel of small engines. That's how most riding lawn mowers function. I also know that some generator heads have the option of a 12vdc charge source, because most of your portable electric start generators have that.

Typically, both those options are only about 10-20 amps of power, but I would think that would be sufficient to charge a vehicle battery back up after it starts the generator. Then you can use the generator head to charge your house bank back up.
__________________
The Silver Bullet https://www.skoolie.net/forums/f11/p...llet-9266.html
Booyah45828 is offline   Reply With Quote
Old 06-26-2020, 08:04 PM   #19
Bus Crazy
 
Join Date: Nov 2016
Posts: 1,655
KISS

If you already have the genset, use your high-amp mains charger to charge (all) your banks together.

Ideally only when the solar just can't keep up, or when you need to run it for other stuff.

Ability to vary the amps output helps in balancing multi tasking.
john61ct is offline   Reply With Quote
Old 06-27-2020, 05:41 AM   #20
Bus Crazy
 
Ronnie's Avatar
 
Join Date: Oct 2017
Location: Virginia
Posts: 1,575
Year: 1971
Coachwork: Wayne
Chassis: International Loadstar 1700
Engine: 345 international V-8
Quote:
Originally Posted by Booyah45828 View Post
Yeah, I wouldn't want it on the bus engine. Definitely on the generator.

I wonder how hard it would be to rig up an onan to charge it's batteries. I know they make small alternators that work off the magnets in the flywheel of small engines. That's how most riding lawn mowers function. I also know that some generator heads have the option of a 12vdc charge source, because most of your portable electric start generators have that.

Typically, both those options are only about 10-20 amps of power, but I would think that would be sufficient to charge a vehicle battery back up after it starts the generator. Then you can use the generator head to charge your house bank back up.
There,is something in thr service manual about making my generator able to charge some. Do not really remember what , but it was similer to what you are saying. Might be just a regulator that needs to be added. At least I know it is an option.
Ronnie is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 04:51 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
×