| Author |
Message |
Peter Broadribb (Madbrit)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 30, 2005 - 2:04 am: | |
Guys,
Having installed my genset at last, we decided to use the motor/start batteries to start the genset. What happens if I run the genset whilst I have the engine running? It would mean that two alternators would be charging the same battery bank at the same time. Is this a good, bad or no problem thing?
I don't want to cut out either charging system permanently as the genset can keep the batteries up when parked and the motor can do it when driving, it is just that time when one has the genset running whilst travelling down the road that is my concern.
Thanks.
Peter. |
Brian (Bigbusguy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 30, 2005 - 2:32 am: | |
I think I would just run it off a seprate batt just for the gen set then if the start batts went dead you could start the gen set or the other way.
The way you have it hooked up I would not think it would be a problem but if the gen set volts for batt charging was higher then the bus alt it would take up most of the load and could be running at max all the time and would not take to long to burn up.
If you want to keep the bus start batts up use a charger pluged into the gen set 110 V.
Just my way of thinking.
Brian 4905 Klamath Falls Oregon |
Gillig-Dan
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 30, 2005 - 9:38 am: | |
I agree with Brian. You're going to want a 110VAC battery charger it most cases. I use a standard unit I picked up for $50. I can move it to which ever battery I need charged. You could make a switching system inside the bus to redirect its output. I personally don't need that level of sophistication since my bus is just a family camper. My generator has its own battery. I can clip the charger to my house batteries, through the onboard inverter going down the road or shore power when parked.
Gillig-Dan |
Stan
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 30, 2005 - 10:09 am: | |
A large diode in the cable to the genset will stop any back feed to the engine battery. Unless your start batteries are at the end of life, there is no need to keep them on charge when parked. |
Randy Davidson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 30, 2005 - 6:54 pm: | |
What kind of genset do you have? Mine is an Onan and is connected to the start batteries just as you are doing. My genset alt has a pin connection that when 12v are applied will turn off the genset alt. So, all I have to do is run a lead from the bus alt to the genset alt to indicate the bus is doing the charging.
Or, on second thought, the 12v need not come from the bus alt, but any 12v circuit that is hot when the bus is running. That would be easier.
As you might deduce, I've installed my genset but not yet hooked up this wire. So, I don't know if it works yet. |
Peter Broadribb (Madbrit)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 30, 2005 - 8:09 pm: | |
Thanks Guys,
A lot of good info, what I think I will do is buy a manual, especially an installation one, which should show me the various wiring diagrams I can use for my application.
Peter. |
Gary Stadler (Boogiethecat)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 30, 2005 - 11:19 pm: | |
In truth I don't think it would hurt to have two alternators running into the same battery at the same time. Internally, alternators have a set of diodes that would isolate the windings from each other, so there's no major problem if one is spinning and the other isn't. Beyond that, each alternator would have it's own regulator that would sense the battery voltage and cause the alternator to add charge to the system or not, regardless what the other is doing.
So consider what would happen...Alternator #1 is charging away and you turn on alternator #2. If #2 thinks the battery is too low, it will send power to the system. But if #1 already has the voltage up high enough that no charge is needed, #2 will think it's ok to cut back. Same thing will happen the other way around.
The only thing that could cause problems is if one of the alternators "ran away" and tried to force the voltage up too high, but that wouldn't happen, it's regulator would cut it back automatically.
Now one alternator may be "favored" by the system and always be the one charging, leaving the other mostly unused, but it will probably be the bigger one (main engine) and the genset alternator will just stay mostly out of the picture. In case the regulator voltages were set differently keeping the genset regulator full on, the main engine alternator would simply add power as needed...
Is this all clear as mud? basically I doubt any harm will come of it no matter what the situation, and you should be fine hooking both alts to one batt. No diodes needed....
BTW, this is how my bus is hooked up and I've never had a problem.... |
Peter Broadribb (Madbrit)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, January 31, 2005 - 1:07 am: | |
Gary,
Thanks for the input. The only time they will be running together is when it's really hot and I have people in the back whilst travelling. Otherwise it would rarely happen as the Freightliner has its own dash a/c. Ofcourse if the little woman wants to get dinner on the go, then the genset would be on to power the convection/microwave oven as we don't have a propane one due to space restrictions.
Btw, these Onan Quiet Diesels are a trip, with it running you can't even feel any vibration in the support frame,let alone in the floor of the bedroom, which is above.
Peter. |
|