Generator battery

[Mex-Busnut]

Dear Friends,

I am wondering if I really need a separate battery for my generator's starter, (I actually do have a small Volkswagen bug battery I could use.) or is it O. K. to use the house batteries that are in the same cargo bay as the genny?

My generator does NOT have capability to charge the starter battery.

Thanks in advance for your input!

[edvanland]

I start my generator off the house batteries, why have a seperate batter?
ED
MCI 7

[Oonrahnjay]

I start my generator off the house batteries, why have a seperate batter?
ED
MCI 7

    If I trusted myself to not do something stupid and run down both the house and start batteries, I'd feel the same way.  But I'm gonna like the redundancy that a separate battery will give.  At least then, I'll be able to start the gennie and charge up the start batteries and get going.

    And, Steve, I'm the last one to offer electrical advice but I think I've seen that it's pretty easy to rig up a separate battery charger to charge your starter batteries off your generator/house system.  I hope that somebody who knows will fill in that blank for you. 

[technomadia]

The reason we are keeping our genie start battery separate is for the redundancy as well. 

If the house battery system is dead, this allows us a way to start the generator to get it back up.  (Ours isn't yet hooked into the bus engine's alternator or solar panels, which would be additional charge sources that one might have to give you that redundancy while not plugged in.).

- Cherie

[luvrbus]

Cherie,he has redundancy on his generator it is called a pull start rope sorry I could not help myself 


good luck

[Mex-Busnut]

Thanks for your input, gentlemen!

Yes, I do have the pull-start chord on my generator as well, for a backup. But since I already have a spare battery, and I also have a spare small 6-amp battery charger, I guess I will probably go ahead and use them.

[TomC]

My generator is wired to the starting batteries.  Then if the house batteries are dead, can still start the generator.  Course, I do have a jumper solenoid that can jump the starting to house batteries-helpful to charge the house batteries going down the road. Good Luck, TomC

[gus]

Any rig should have a switch to separate the house and start batteries. There is no excuse for discharging all the batteries at the same time.

This gives you all the redundancy you need.

[bobofthenorth]

Any rig should have a switch to separate the house and start batteries. There is no excuse for discharging all the batteries at the same time.

This gives you all the redundancy you need.

I agree with the "no excuse for discharging all the batteries" part but not with the separate house and start batteries.  If I was starting from scratch I'd have one big bank that started the engine and ran the house.  In my case it would be 5 x 8D.  Then I'd have a single Group 31 battery to start the genset.  That's the way my boat is set up and at first I thought it was dumb but the more I got to know it the more sense it makes.  Right now I'm carrying around 2 x 8Ds that get used for 3 or 4 seconds roughly every 3 or 4 days on average.  That's silly.

[gus]

Bob,

The only problem with that theory is that start batteries don't take kindly to long term slow discharge.

House batts should be slow discharge (deep cycle) because they handle it much better.

It won't hurt to have a separate genset battery but if you have the house and engine batts separated it is like wearing suspenders with a belt.

The good thing about being a bus nut is you can do anything you like with your bus that doesn't harm others!!

[bobofthenorth]

I would use deep cycle batteries for the entire bank.  The starting loads would easily be handled by the deep cycles because there would be such a huge excess capacity.  The generator would be separate on its own starting battery.  That's exactly how our boat is wired and like I said, at first I thought it was dumb but I have come to think it is the sensible way to do things.  When our current Lifeline AGMs eventually die I expect we will end up with 5 x 8D AGMs to replace them and I will alter the wiring accordingly.

[Mex-Busnut]

Any rig should have a switch to separate the house and start batteries. There is no excuse for discharging all the batteries at the same time.

This gives you all the redundancy you need.

You understand we are NOT talking about the engine start batteries, but a separate battery for the generator's starter, right? Just want to make sure!

[belfert]

I have a separate genset battery.  The battery came with the original genset I bought.  I later switched gensets, but kept the battery.  At the time I never thought about connecting to the house batteries, but it would probably cost more for the long cables required than to buy another battery when necessary.

I was thinking about it this summer that my generator battery is fairly old.  It was used when I got it more than five years.  I have no idea how old it really is.

[Joe Camper]

Yes Dr. Steve the thread expanded a bit.

I would give the Gen its own battery separate from the house battery's.

You could also connect the gen to the house bank with a cable that runs thru a start solenoid that you could control from the control panel in the bus.

When energized it would be sending charge to the gen battery while your driving and also allow you to jump start the gen should that battery get low  AND still be able to have the 2 banks isolated when everything is good to give you back up and redundency.

This is how our camper is wired.

We also have the chassis and house banks configured the same way. They are both 24 volt and with the big alternator. I can tie them togeather when we are driving and separate them when we are not.

Wiring a start solenoid in is a very simple project. If the banks are separated to any degree use the correct size cable carry the loads. This will be the only real expence of doing this.

Our gen has an alternator and it gives us the additional option of charging the house bank off the gen alt too and you would be suprised how well that little alt on the gen keeps the house bank up if the inverter charger is out.

[luvrbus]

Steve if go the solenoid route for charging it has to be a constant voltage solenoid a regular starter solenoid will just melt they are made for momentary volts only   


good luck