Addition to post below

[Ace]

regarding bus won't stay running!

A recent scenario I encountered just yesterday and it might be something to consider. Since I have been very busy lately with moving, building, painting, and of course trying to work when I can, the bus got put on the back burner so to speak but, decided it was time to go get it from old house and bring it home to our new house. OK it ran fine the last time we took it out which was a very short trip to the speedway and back home. A total trip of around 20 miles give or take. Parked it in the usual place and literally forgot about it until yesterday when I thought I would fire it up and bring it home. No can do since the batteries were dead. No problem! Get out the 12v charger and give it a quick charge on one battery at a time. There are four of them so it takes a little time. After doing three, and being impatient as I am I decided to give it try. It fired right up no problem BUT, the check engine light and stop engine light came on and eventually shut down. HMM now what? Tried it again and again and even again with the same results. Air pressure built up during the 10 or so tries when it was running, Checked the water and oil, both full and the oil pressure was right up there at 50lbs.
Had a theory and hoping this is the case. I even called Jack Conrad to discuss my theory and he leaned toward thinking the same thing. My theory is that the batteries just don't have enough juice in them to supply the DDEC to maintain the electronic sensors even though they have just enough to start the engine. I forgot to mention that I checked the codes usi9ng the blinking lights and found that I had 3 faults. All 3 were "low voltage sensor" related which led me to my theory! Now I will charge the batteries fully at a slow charge and try it again!
Though in the last post I mentioned that it was probably a faulty sensor, it could be too that the batteries  are just too low to supply the DDEC the juice it needs! Jack and I are thinking that the DDEC needs a certain amount of voltage to operate it and all the related sensors correctly and in my case of neglect, it just isn't happening!

Hope this helps!

Ace

[belfert]

Interesting.  I have had to charge my batteries a number of times due to my negligence/ignorance.  The first few times I charged each of the four batteries seperately.  On later tries I only did two or three of the batteries as Ace did.

My coach has a DDEC III and it started and ran just fine with just two or three batteries charged.  I did buy another 12 volt charger the same as my first one so I can hook the chargers together so I charge the whole bank at 24 volt.  (Yes, I checked the output from the chargers before I hooked to the battery bank.)

I am going to buy new batteries this spring as they don't hold a charge at all at 20 degrees after the abuse I gave them last summer.  The local bus garage had to jump start it after it sat there a few days this winter.  When I tried to start it just three days later the batteries were dead again.

Brian Elfert

[Ncbob]

FWIW...we who have the older uses can probably get away with charging the 24V system (usually 8D's) with a regular 12V battery charger but you fellas with the electronic control systems should probably think of using a 24V charger.

Ace...had I known..you could have borrowed my 24V charger.  I carry it with me when I travel but I've never used it.  It's here should you need it...I won't be leaving until the morning of the 10th.

Bob

[belfert]

FWIW...we who have the older uses can probably get away with charging the 24V system (usually 8D's) with a regular 12V battery charger but you fellas with the electronic control systems should probably think of using a 24V charger.

If I charge one 12 volt battery by itself I disconnect all of the cables from it first.  No way I want to fry a $900 DDEC.

I originally bought a 12 volt charger since I needed something in a hurry and nobody local had a 24 volt charger.  When I decided it is faster to do 24 volt instead of 12 volt, I bought another 12 volt charger to use in series as I couldn't justify the cost of a 24 volt charger.  I still needed a 12 volt charger around the house anyhow.

If I would have had the time when I bought the first charger I would have done 24 volt.

Brian Elfert