| Author |
Message |
Buddy Tennison (Buddyten)
Registered Member
Username: Buddyten
Post Number: 45
Registered: 7-2005
Posted From: 207.68.234.24
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 30, 2007 - 10:52 pm: | |
Hey Guys: I have an Onan Marquis 7.5 KW Gen. I use a deep cycle marine battery just to run the gen (cause I had an extra one from my boat). I keep a standard battery charger on it to keep it up. Question is: Will a 1.5A "trickle" charger keep this battery up sufficent to run the Gen?
Reason I ask this is a couple weekends ago, I went to check the gen. The battery charger had malfunctioned (apparently) and tripped the breaker at some time during the weekend. I ran for another day and a half with no battery charger on the battery, and it still was putting out power to crank and run the gen. Got me to thinking, do I really need to run more than a trickle charger. |
FAST FRED (Fast_fred)
Registered Member
Username: Fast_fred
Post Number: 107
Registered: 10-2006
Posted From: 66.90.229.227
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 01, 2007 - 6:23 am: | |
If the noisemaker battery is powered 24/7 except for short times , probably.
A wet batt will loose 1% to 3% per day of sitting , so you dont have much recovery with a trickle charger , unless always operating.
FF |
Richard Bowyer (Drivingmisslazy)
Registered Member
Username: Drivingmisslazy
Post Number: 2016
Registered: 1-2001
Posted From: 75.108.84.4
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 01, 2007 - 11:23 am: | |
I strongly suspect that the Onan has an alternator whose purpose is to maintain the charge on the start battery while the genset is running. Unless you go for many months, years?) without running the genset, you have no need for an alternate battery charger.
I have an identical genset installed for emergency power at my home and I typically start it every six months and run it for 15 minutes. It has now been installed about five years and the battery is still fully charged without the aid of an auxiliary battery charger.
Much better would be a method of connecting the house or start batteries to the genset battery in case it is ever run down enough to not start the gen set. Even a set of jumper cables to jump the genset, if ever needed, would be all you need.
Richard |
Jerry Liebler (Jerry_liebler)
Registered Member
Username: Jerry_liebler
Post Number: 305
Registered: 3-2005
Posted From: 75.117.212.57
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 01, 2007 - 1:45 pm: | |
Buddy,
Be careful with 'ordinary' trickle chargers, they can 'boil' batteries dry. What you want/need is a 'float' charger. The float charger has a regulated output voltage and will keep the connected battery fully charged yet avoid gasing away the water. I use one I got from Harbor Freight for about $7.00 when on sale. It will put out an amp but regulates at 13 volts which is just right. The 1 amp output should handle even an 8D sized battery's self discharge.
Regards
Jerry 4107 1120 |
Jim Wilke (Jim Bob) (Pd41044039)
Registered Member
Username: Pd41044039
Post Number: 223
Registered: 2-2001
Posted From: 68.153.238.214
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 01, 2007 - 8:37 pm: | |
I have been using a cheapy 6 amp battery charger to keep the 2 8d starting/house batteris charged in my bus. I got one of those timers that turns on a lamp or TV at home & plugged the charger into that. The timer is set to turn on for 2 hours a day. It has kept those two 8Ds nicely charged for about 4 years now. (Before that, little psky discharges would drain them in a month or so.)
Jim-Bob |
Gus Causbie (Gusc)
Registered Member
Username: Gusc
Post Number: 550
Registered: 11-2005
Posted From: 63.97.117.46
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 01, 2007 - 8:56 pm: | |
If your Onan is like my old one it requires a battery hookup when running which, I presume, was to keep from destroying the alternator built into the gen flywheel. I don't know what else it would do to the gen if no battery was hooked up while running?
My Onan was originally a dwelling standby gen so it needed to charge the battery but this feature is nothing but a nuisance in a bus.
If you connect it to the bus batteries while it is running it confuses the bus alternator and makes it do crazy things.
Like Richard says, my solution was to hook an old lawnmower battery (Any weak old battery will do, even a small motorcycle battery, as long as it is not shorted and will take a charge even if it won't hold it) to the gen plus a solenoid which would connect the bus battery to the gen battery for starting. I had a toggle switch next to the gen remote control panel to energize the solenoid when needed.
The gen ignition is probably solid state so it takes very little current to operate. |
Austin Scott Davis (Zimtok)
Registered Member
Username: Zimtok
Post Number: 195
Registered: 9-2006
Posted From: 216.37.73.226
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 03, 2007 - 10:35 am: | |
My bus is still positive ground, my Onan gen-set is negative ground.
The previous owner had the Onan battery wired to the bus electrical system to keep it charged. It was done "correctly" (positive of battery to ground of bus) but he always had dead battery problems.
Once I got the bus and separated the Onan battery from the bus charging system the dead battery problems went away.
I now have a small "floating" battery charger hooked up to the Onan battery so it will keep it charged up anytime the generator is running or if I'm connected to shore power. It's been that way for over a year now with no problems.
. |