Low voltage alarm sporadically prevents starting on fully charged batteries

[Pilot]

Smartcraft alarm, prevents starting one engine. I Put a voltage meter on, all batteries check out fine, 12.5V. This happens occasionally, cables seem tight, not corroded,. Any thoughts? Is there a replaceable sensor?

 

[dtfeld]

Smartcraft alarm, prevents starting one engine. I Put a voltage meter on, all batteries check out fine, 12.5V. This happens occasionally, cables seem tight, not corroded,. Any thoughts? Is there a replaceable sensor?

Are you saying that smartcraft shows a different voltage? Only happens when starting? What type battery and how old?

No load voltage doesn't mean too much, its the voltage under load that matters, hence the reason to load test batteries. If smart craft is showing about the same voltage as volt meter, I would start by pulling and load test the battery(s) first.

 

[scoflaw]

Be easier to do a voltage drop test at the 50 amp breaker. That would be real world testing, I don't believe those little hand held ones.

 

[Pilot]

Are you saying that smartcraft shows a different voltage? Only happens when starting? What type battery and how old?

No load voltage doesn't mean too much, its the voltage under load that matters, hence the reason to load test batteries. If smart craft is showing about the same voltage as volt meter, I would start by pulling and load test the battery(s) first.

Thanks. All checks out the same. One more thought,, I believe this could possibly be caused by a loose or corroded connection to the starter which I will check next. It would like send a low voltage signal back.