Cold cranking speed?

[ttyR2]

Should my Powerstroke crank over smartly when it's 25deg or so out? Or will I notice it spinning over a lot slower than when its 50 out? I'm wondering if the batteries in the truck are getting tired. For the first time, it barely started yesterday, at about 30deg.

[NoRalPh]

Mine cranks slower even with new batteries but if it's "barely" starting now, you're gonna have trouble when it gets Really cold!

Load Test time I'd think.... Make sure they're fully charged first, test them individually, and because they're big batteries make sure the guy "puts-the-spurs" to 'em (people are saying their bad batteries are passing a Half-A$$ed load test, with only a 100Amp load on them at Auto Parts stores.). So you want a 300-400A load to really test these batteries...

Also remember, once the PCM see less than 100rpm (normal is 150-200) it stops sending the IDM signal to even Try to start.

[ttyR2]

Had the batteries tested and the driver side battery dropped to 4V under a load test, and it has a dead cell. So...new batteries on order. I'm impressed the truck started as well as it did with a dying battery in the system.