Run time with no generator system

[squirebill]

Looking for a guesstimate of how long a B1B will run without an operating generator system. Would like to drive the truck in the upcoming 4th of July parade and not sure will have an operable genny system by then.  Have been currently running the engine off a 12 volt battery, positive ground with a switched lead to the coil.  Maximum run time has been 15 minutes or so to check operation of cooling system thermostat, etc. Anybody have a guess or experience with a failed generator system and still able to drive running off the battery only?

[Merle Coggins]

I once drove from Minneapolis to Appleton, WI to Waukesha, WI with a faulty voltage regulator that would only charge periodically on my 6 volt system. 

[TodFitch]

Assuming something like a 80 or 100 amp-hour battery and a couple amps for the ignition system if you are not running lights, radio, etc. then you should be able to run the truck all day, maybe even two or three days.

Longest I ran a car with a car where the alternator failed in the middle of the desert was about 200 miles. I've talked with others who were able to complete a 1000 mile trip by pulling the battery each night and fully charging it in the motel room then running all the following day. 

[Don Coatney]

If you are running a full 12 volts through the distributor you may have ignition point failure before the battery goes flat.

[squirebill]

Gentlemen....Thank you for your quick replies.   Looks like I will be able to drive in the 2 hour long 4th of July parade with or without an operating genny system. Will take an extra fully charged 12 volt battery just in case.   Don, thanks for warning about the points. Further research indicates adding a  ballast resistor (1.6 ohm) in series in the coil input  line will extend point life when used with -12 VDC input, same as I had on my '64 Plymouth Valiant.  In fact I found a 12VDC ballast resistor still in the original packaging in my "old car parts box" in my garage.  Best regards to all.