Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > RV SYSTEMS AND TECHNOLOGIES FORUMS > RV Systems & Appliances
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 01-28-2014, 03:15 PM   #1
Member
 
Join Date: Nov 2013
Posts: 65
Generator starting battery question

I just bought a Onan 5500 propane generator and I'm building a 24v battery bank out of eight 6v 225ah batteries. This is for a concession trailer I'm building and wanted a few hours of quiet time running on batteries. Everything in the trailer runs on 110v.

I cannot somehow tap into the battery bank to get 12v out of it correct?

If I install a separate 12v automotive battery how do I charge the battery. Can it somehow be charged from my truck when hooked up to the trailer. And if so, how does the wiring go.

If not, I'd probably have to buy a trickle charger and plug it in overnight a few times a week right?

Thanks
Jasper7821 is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 01-28-2014, 04:40 PM   #2
Senior Member
 
Old Bounder's Avatar
 
Fleetwood Owners Club
Ford Super Duty Owner
Join Date: Mar 2009
Posts: 1,636
Quote:
Originally Posted by Jasper7821 View Post
I just bought a Onan 5500 propane generator and I'm building a 24v battery bank out of eight 6v 225ah batteries. This is for a concession trailer I'm building and wanted a few hours of quiet time running on batteries. Everything in the trailer runs on 110v.

I cannot somehow tap into the battery bank to get 12v out of it correct?

If I install a separate 12v automotive battery how do I charge the battery. Can it somehow be charged from my truck when hooked up to the trailer. And if so, how does the wiring go.

If not, I'd probably have to buy a trickle charger and plug it in overnight a few times a week right?

Thanks
Absolutely, you can tap off 12V from within your 24V battery array. But, that kind of knocks a hole in your statement that "Everything in the trailer runs on 110V".

EDIT - It just occurred to me that you are needing 12V to start the generator. A separate battery and charger may be the answer, but you could, indeed, tap into the array to obtain 12V for that purpose.
__________________
'97 Bounder 34V, F53 7.5L-460
Old Bounder is offline   Reply With Quote
Old 01-28-2014, 05:09 PM   #3
Senior Member
 
Fleetwood Owners Club
Join Date: Dec 2004
Posts: 527
Yes, you can get 12 volts from the bank. Charging the bank is then the question because you should take equal amps from all the batteries. If you are charging them with a 24v charger and if you are taking 12v from half of them, that portion of their charge will never be replaced. The Onan probably has a 12v tap which will keep a small starting battery charged. A voltage regulator would be required if that is not provided in the Onan system.

How are you charging and what are you using 24 volts for.
targaboat is offline   Reply With Quote
Old 01-29-2014, 12:23 AM   #4
Member
 
Join Date: Nov 2013
Posts: 65
Thanks. I'm just trying to not have to buy another battery. My 8 battery bank will be charged from the generator when they get down to 20% used. I'll be using a 24v 4000 watt inverter. The total peak draw from the trailer with the appliances will be about 15 amps not including the AC since that will run off the generator only and the appliances will run off the batteries.

I guess it sounds a lot simpler to get a small 12v battery just to start the generator. I don't know if the generator charges that battery or not. If so that would be great. If not then I'll have to charge it somehow.

I know nothing about generators or battery bank systems or inverters. I just wanted my concession trailer not to gave to use the generator to power it all day long. I calculated that I'll be able to run the trailer off just the batteries for 3-4 hours and that will give me the quiet time I wanted. Of course in the summer the AC will be on the whole time so then the generator will also gave to run all day long.
Jasper7821 is offline   Reply With Quote
Old 01-29-2014, 03:27 AM   #5
Senior Member
 
Join Date: Nov 2005
Posts: 4,063
I would have gone with a 12 volt inverter/charger with generator autostart so you could just set is and forget it. It would then take care of any quiet times, monitor the air conditioning starting the generator automatically when the thermostat calls and monitor the charge on the batteries automatically starting the generator when they need to be topped off.

I can't imagine being without the Autostart now that I have gotten use to it.
__________________
Neil V
2001 Winnebago Adventurer WFG35U
NeilV is offline   Reply With Quote
Old 01-29-2014, 05:06 AM   #6
Senior Member
 
Fleetwood Owners Club
Join Date: Dec 2004
Posts: 527
Still seems that you are not charging the 24v battery bank. The inverter is accounts for your 120v. You need a 24vDC converter. That converts the generator produced 120 AC to the 24v DC to charge the battery. It's possible what you call the inverter is dual function, converter and inverter combined, but the RV people seldom see 24 volts.
targaboat is offline   Reply With Quote
Old 01-29-2014, 05:14 AM   #7
Senior Member
 
Fleetwood Owners Club
Join Date: Dec 2004
Posts: 527
Here is a 3600 watt inverter/converter for 36 volt battery.

APS3636VR | Tripp Lite
targaboat is offline   Reply With Quote
Old 01-29-2014, 01:07 PM   #8
Member
 
Join Date: Nov 2013
Posts: 65
Quote:
Originally Posted by NeilV View Post
I would have gone with a 12 volt inverter/charger with generator autostart so you could just set is and forget it. It would then take care of any quiet times, monitor the air conditioning starting the generator automatically when the thermostat calls and monitor the charge on the batteries automatically starting the generator when they need to be topped off.

I can't imagine being without the Autostart now that I have gotten use to it.
Thanks, I looked at that Autostart and it was pretty pricey. I haven't bought the batteries or inverter yet so I can install whichever I want. The RV dealer told me to use 24v since the inverter is the same price as 12v and I can use 1 ott wire instead of 4 ott wire and that will save money. And they also said it will be more efficient.
Jasper7821 is offline   Reply With Quote
Old 01-29-2014, 01:14 PM   #9
Member
 
Join Date: Nov 2013
Posts: 65
Quote:
Originally Posted by targaboat View Post
Still seems that you are not charging the 24v battery bank. The inverter is accounts for your 120v. You need a 24vDC converter. That converts the generator produced 120 AC to the 24v DC to charge the battery. It's possible what you call the inverter is dual function, converter and inverter combined, but the RV people seldom see 24 volts.
The inverter is a converter and charger too and will charge the 24v battery bank.
4000 Watt 24 volt Low Frequency Inverter Charger

Again, I know nothing about generatos or battery banks. I'm just doing what the inverter and RV company suggested.
Jasper7821 is offline   Reply With Quote
Old 01-29-2014, 02:03 PM   #10
Senior Member
 
Fleetwood Owners Club
Join Date: Dec 2004
Posts: 527
Now that we have the whole story we are able to help. Here is a whole page of 24 to 12 volt converters which would be far better then a separate battery to have to worry about. We used these on newer airplanes which had 24 volt systems and older electronics and some of the controls such as flap motors which needed 12 volts.

24 volt to 12 volt DC/DC converters (fully regulated) from 100 to 700 Watts both non-isolated and isolated.


An they do not appear to be very expensive. Now we need to find out how many amps is required to start the generator. It maybe in the specs for the genny. Another way to approach this is to determine the size of the fuse in the starting circuit. Can not imagine it is more than 20 amps.
targaboat is offline   Reply With Quote
Old 01-29-2014, 02:08 PM   #11
Senior Member
 
Fleetwood Owners Club
Join Date: Dec 2004
Posts: 527
Lets work on terminology, an inverter changes DC to AC, a converter changes AC to DE. The boxes which do both have both inverter and converter built in. What the English majors put in advertising copy does not count.
targaboat is offline   Reply With Quote
Old 01-29-2014, 02:14 PM   #12
Senior Member
 
Fleetwood Owners Club
Join Date: Dec 2004
Posts: 527
You are building a neat system. I would like to see what solar panels would do for you. For that we really need information on your usage history which you probably do not have at this point. We would also need a better picture of your set up to even come close guessing your energy requirements.
targaboat is offline   Reply With Quote
Old 01-29-2014, 02:55 PM   #13
Registered User
 
Monaco Owners Club
Join Date: Oct 2009
Location: Varies Depending on The Weather
Posts: 8,517
Quote:
Originally Posted by Jasper7821 View Post

I just bought a Onan 5500 propane generator and I'm building a 24v battery bank out of eight 6v 225ah batteries. This is for a concession trailer I'm building and wanted a few hours of quiet time running on batteries. Everything in the trailer runs on 110v.

I cannot somehow tap into the battery bank to get 12v out of it correct?

If I install a separate 12v automotive battery how do I charge the battery. Can it somehow be charged from my truck when hooked up to the trailer. And if so, how does the wiring go.

If not, I'd probably have to buy a trickle charger and plug it in overnight a few times a week right?

Thanks
Is this the LPG Generator model that you purchased? If so, here is the Specification Sheet for that model.

https://powersuite.cummins.com/PS5/P...ets/a-1425.pdf

WRT your 24 VDC Battery Bank by using eight 6 VDC Batteries, I assume that you are planning on connecting each of the four sets of 6 VDC batteries tied in series to form 24 VDC, then the 8 batteries will be connected in Parallel to give you the 24 VDC with about 450+ AH if using the Sam's Club Golf Cart GC-2 Batteries.

The 24 VDC 4000 Watt Inverter/Charger you have chosen will work well with your 24 VDC Battery Bank. I am assuming that the generator will be used to keep the battery bank charged or are you planning to use shore power?

You should NOT tap 12 VDC from your 24 VDC battery bank to start your generator. You will need a separate 12 VDC battery to use for starting the generator. That battery should be charged using either the generator and a 12 VDC battery maintainer or by using shore power. You can also charge the 24 VDC battery bank using the generator or shore power.

If you plan to use the generator for charging all of the batteries, figure on 3-4 hours of run time to do that. It is far more efficient to use shore power than generator power for charging batteries.

Here are a couple of documents that will help you with battery types, inverter's etc.

The 12volt Side of Life (Part 1)

The 12volt Side of Life Part 2

My final comment is regarding your statement about running the battery bank down to 20% BEFORE recharging. Where did you get your information regarding that data?

If you read the very first document listed above, it warns people NOT to use the battery bank to a lower level than 50% SOC. If you do, then the lifespan of your battery bank will be significantly reduced requiring you to purchase batteries far more often than you may want to.

Dr4Film ----- Richard
Dr4Film is offline   Reply With Quote
Old 01-29-2014, 08:02 PM   #14
Senior Member
 
Old Bounder's Avatar
 
Fleetwood Owners Club
Ford Super Duty Owner
Join Date: Mar 2009
Posts: 1,636
I'm not sure why folks here are so opposed to tapping off 12v from your battery bank to start your generator. It's not likely that you would use that tap for more than a few seconds, once a day, and that would be just to start the gen and the recharging process. Where's the harm? It's the cheapest, best and most efficient way to go.

Note to Dr4film, I think the OP meant recharge at the 80% level. His words were "at 20% used".
__________________
'97 Bounder 34V, F53 7.5L-460
Old Bounder is offline   Reply With Quote
Reply

Tags
battery, generator



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Battery Advice sjkted Class A Motorhome Discussions 33 02-06-2014 09:12 PM
Battery Question spinn Newmar Owner's Forum 10 01-24-2014 05:48 PM
Question about battery bank system and length of wire to purchase Jasper7821 RV Systems & Appliances 9 01-24-2014 03:48 PM
Serrano Battery Question Penguy Thor Industries Owner's Forum 1 01-09-2014 08:31 PM
Battery charge question rvtime2 iRV2.com General Discussion 19 01-02-2014 07:43 PM

» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 05:18 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2023, vBulletin Solutions, Inc.