About how many amps does it take to keep a 455 running at 2000 rpm, along with dash gauges? Does it take more if the engine is under load?

How low can a battery be discharged before it will no longer drive the coil?

Just wondering how far I could drive on a 50 AH battery if the generator fails.

 

Its hard to tell because there are too many variants to the question. Here is a good read:
http://vonwentzel.net/Battery/00.Glossary/

 

This is a good question. A larger capacity battery will last longer but load has a lot to do with it.

I think we have discussed what HEI requirements were, at about 5 amps if I recall. But there are other losses too. lights,fan,radio, clock...

Lots of variables.

I once tested this by accident, at night and pretty chilly weather. I replaced an alternator but forgot to hook up the plug. I got 10-12 miles or about 30 minutes. But...I was probably using a weak battery to begin with..previously failing alternator considered.

 

Without headlights, probably about an hour, at least. The biggest draw is obviously the starter motor. Once started, the engine uses precious little electrical power. Be sure all other loads are turned off, like fan motor, radio, etc.

 

Thank you guys for your responses.

 

If you need to go farther or as a backup, carry a few charged up ones.

 

Ah - probably easier to pack a spare alternator.