| Author | Message | ||
| Buddy Tennison (Buddyten)
Registered Member Username: Buddyten Post Number: 82 Registered: 7-2005 Posted From: 207.68.234.50 Rating: N/A |
We have an Onan 7000 Marquis Gas Powered in our bus. I have been using a standard 12V battery on it, with a 10A battery charger. Is this overkill? Do I really need that much battery and charger? Will a motorcycle/lawn mower battery work as well (and yes I understand they are 12V). Will a 2A Trickle charger keep the battery up to operate the genset? Any suggestions appreciated | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 394 Registered: 2-2001 Posted From: 69.77.144.102 Rating: N/A |
Well the generator charges the battery when it runs. If you don't have any significant electrical draws when the unit is shut off, a 2A trickle charger will work fine. I use a 10A charger set up on a timer so it runs only about 1 hour per day to keep the 2 8D engine batteries charged in our bus. (12 V bus). | ||
| Bob Baldwin (Bob4106)
Registered Member Username: Bob4106 Post Number: 178 Registered: 10-2004 Posted From: 24.74.180.20  Rating: N/A |
From my understanding not all Onan generators will charge or keep a battery up.I think that most Onan generators where used on RV"s. Where they used the 12 volt converter to keep the battery up. | ||
| clint hunter (Truthhunter)
Registered Member Username: Truthhunter Post Number: 475 Registered: 1-2009 Posted From: 24.129.232.219  Rating: N/A |
to trickle charge or not... ~ don't overcharge or you will shorten the battery life , quickly with big 10 amps set on manual charge for long periods; only a battery test under normal use will indicate (on a good battery) with a degree of certainly if you need extra charge time, a hydrometer test is a indication of , but only a CA tester will give accurate test results of battery state of charge. - if battery weight & size is not a issue , the bigger the battery the better , more & longer dependability you get on generator starts, small batteries are much less forgiving, especially to massive overcharge cycles and age , with little room for cold starts in a depleted state. +a timer sure does modernize a manual charger, good idea, compact & multi purpose too. Good application thier jIMbOB... | ||
| Austin Scott Davis (Zimtok)
Registered Member Username: Zimtok Post Number: 370 Registered: 9-2006 Posted From: 216.37.73.226  Rating: N/A |
I have an Onan generator in my bus. the PO had the battery getting its charge from the bus 12v system. Because the bus is still positive ground and the generator is negative ground he constantly had problems. he tried to keep the generator ground isolated from the bus ground. I now have the generator isolated completely. And it powers a floating battery charger set to 2 amps. This has been working for over two years keeping an 8D battery charged. I should mention that the charger is also connected to shore power to charge then also. . | ||
| Pete/RTS Daytona (Pete_rtsdaytona)
Registered Member Username: Pete_rtsdaytona Post Number: 578 Registered: 1-2005 Posted From: 97.104.13.102  Rating: N/A |
I use a small garden tractor battery and this float charger from Harbor frieight - http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=99857 - I find this one JUST AS GOOD as the EXPENSIVE "Battery Tender Brand" - I us them on my Motorcycle also Harbor freight has another float charger that's cheaper - but that a piece of $hit | ||
| David Lower (Dave_l)
Registered Member Username: Dave_l Post Number: 199 Registered: 11-2007 Posted From: 67.58.201.132  Rating: N/A |
Pete would you know if this float charger would work on the bus batteries I have one like it that automaticly goes from 12 to 24 to 36 volt depending on the batteries it maintains them at a floating charge that goes up and down as needed. I bought it for an electric bike but the bike was stolen before i took it out of the box. Dave L | ||
| Wec4104 (Wec4104)
Registered Member Username: Wec4104 Post Number: 66 Registered: 7-2008 Posted From: 68.80.242.72 Rating: N/A |
Since my bus engine electricals are 12V, I do not have a separate battery for my Onan generator. I just start the Onan from the bus engine battery bank. I didn't realize until this discussion that lots of folks have separate batteries and trickle chargers. | ||
| Don Evans (Doninwa)
Registered Member Username: Doninwa Post Number: 228 Registered: 1-2007 Posted From: 208.81.157.90  Rating: N/A |
Easy to find out if your genset has a built in charger or is being charged by something onboard. Check the battery voltage with the genset off. Check it again after starting the genset. If you have a built in charger or the genset is being charged by something in the bus the voltage will be higher when the genset is running. Don 4107 | ||
| Larry & Lynne Dixon (Larry_d)
Registered Member Username: Larry_d Post Number: 226 Registered: 7-2005 Posted From: 71.111.185.149  Rating: N/A |
Buddy I have two 8D's on the 4905 which I have two battery tenders hooked up. I have a car battery for the 7.5 diesel gen set with also a two amp battery tender. I have not had a dead battery in two years. I like them so well I have them on a P/U and an 83 Capri V8. Do like the battery tenders. Am buying one more for our van for when we are gone this winter. Larry | ||
| Tom Christman (Tchristman)
Registered Member Username: Tchristman Post Number: 121 Registered: 1-2006 Posted From: 66.218.33.156 Rating: N/A |
For starting the 7kw-yes a garden tractor battery will start it. But-if you ever have problems starting it and have to crank it alot, the tractor battery will die shortly. I would keep with your standard car size battery and use a 10 amp charger with auto shut off. Good luck, TomC | ||
| Frank Allen (Frank66)
Registered Member Username: Frank66 Post Number: 116 Registered: 10-2005 Posted From: 205.188.116.203 Rating: N/A |
I have a 7 kw onan markee, it is equiped with a caherge board, i use a seperate battery for gen set and it stays up all the time, i found the quickest way to destroy the charge board is to try to jump start it, mine will turn over but will not start, after the gen set batt is finally charged the charge board in the gen set is trashed, not all onans have a charge board. Frank Allen 4106 | ||
| Chuck Newman (Chuck_newman)
Registered Member Username: Chuck_newman Post Number: 399 Registered: 1-2005 Posted From: 76.231.250.160  Rating: N/A |
Buddy, I use a 25 amp charger on the engine batteries and a 100 amp charger (in the inverter) for the house batteries. The key here is to use a "smart charger" that will not over charge any battery, even if the charger stays connected forever. I dumped all my manual (non-smart) chargers years ago and have had no problems cooking batteries since. Wec4104, I normally start my generator from center tapped engine batteries. If they are out of steam, I switch a solenoid and start it from center tapped house batteries. Both sets are always on charge when: 1. Engine on; 2. Generator on; 3. Shore power on. No need for a third battery set to maintain. If I let either or both set of batteries run down, then shame on me. But hasn't happened yet. |