I will soon be getting to installing my new house batteries and inverter. The present system runs the generator off the house batteries, and I was thinking of changing that. One option would be a separate generator battery. I was told that a good motorcycle battery would be adequate and would certainly not take up much room. Another option would be to tap off one of the start batteries. I know I have read that doing this for a house system would cause that start batteries to lose balance and cause other problems. However, it would seem to me that just doing it to start the generator is such an intermittent use that maybe it would not effect anything. Of course, I could continue to use the house batteries for the generator too.
I got a good 800 cca battery and separated my house batteries from my gen/start battery. The house batteries are still charged by the gen when it's running.
Seems to work great.
If your generator also charges the starting battery that could cause issues if you center tap your startng batteries.
I have an regular car battery of unknown age for my generator and it always seems to start fine even when the generator hasn't run for a few months.
Just what belfert said would be best.
Point taken about the generator returning a charge to the battery. I was once told by a Kohler service guy that it did not. However, I just put a voltmeter on it and, since it reads 12.9v with the generator running and 12.4 v with it off, it seems that he was wrong.
Lin,
I had an old Onan gen that had a built-in alt in the flywheel. I had it hooked to the bus start batteries and it really fouled up the bus alt.
I finally hooked up a very small lawn mower battery just to the gen with a connection to the bus batteries through a switch so I could boost it if the small battery was ever too weak.
Worked very well.
I use an old 8D that was half of a set for the bus and keep a set of jumpers handy for when it fails.
I know it's overkill but I have it and it is paid for
With some 24 volt stuff and some 12 volt stuff it can get confusing but the reason I have the old 8D is because of a center tap that ruined the other battery.
So my best advice is avoid trying to do 12 volt service with a 24 volt battery bank
Melbo
I know this is a moot point with a 24v system, but I have a 12v system (soo much easier-and my truck is 12v [like all other trucks] too). I tied into the starting batteries for gen operation. I have 2-150amp solenoids in parallel to equal the 300amp output of the alternator for jumping my starting batts to the deep cycle batts. Have started the bus on the deep cycle, and have jumped the house batteries to get the inverter started when I left on a light for several weeks.
One weird thing I discovered, with the gen running through the starting batteries, I had to disconnect the little alternator (wires) from the gen because it was overpowering the big Delco 50DN and causing the alternator light to come on. Weird that a 20 amp alternator could overpower a 300amp, but when I disconnected the small alternaotors wires (still using it just for a belt tensioner), all problems went away. Good luck, TomC
Tom,
I had the same problem. My theory is that the genset alt confused the bus alt regulator, I don't see how it could ever overpower the bus alt because it is so small.
Had the same thing with a mobile command coach.
Once the batteries are up to charge, the generator powered battery charger would fool the bus alternator/regulator into showing a "No Gen" indication. No doubt the bus would show the same to the Gen end, but there was no indicator to the operator.
Due to operational issues, design limitations, etc, it was often necessary for both charging sources to be running.
The "no gen" indication could be easily stopped by adding some coach load, the exterior lighting would usually do it.
This would not occur if there were already substantial coach loads, such as the stock HVAC running.
happy coaching!
buswarrior