Charging/starting issue

[adsm08]

Ok, so here's what I have:

Alternator is about 3 years old

Battery is about 1.5 years old 550 CCA.

Long cranks and very hard starts.

I purposely bought a low amp battery because my truck sits a lot and high amp batteries sulfate and die quicker when they sit. In the last few weeks we have had temps 10 to 15 degrees colder than I anticipated ever having to deal with when I bought this battery.

My alternator is also charging at 14.78V idle, all accessories off.

Is my alternator overcharging and frying the battery, or is it trying to compensate for a battery that isn't up to the temps its being exposed to, which is then being drawn down too far?

Also, does anyone know the correct factory CCA for a battery for an 87 2.9L?

 

[srteach]

14.7V is exactly what a good alternator should put out when running. It charges the battery and runs the truck.
Long cranks and hard starts may be caused by corrosion on the terminals or wiring contacts, or may be a bad or old battery. Not being used causes sulfation and builds resistance in a battery. Higher output causes faster sulfation.
Cold can require higher amps to start. Batteries (like humans) don't like to work when it is cold, and you don't have higher amps to start with.

 

[WJC97]

Long cranks and very hard starts.

My alternator is also charging at 14.78V idle, all accessories off.

Does it crank long or slow? Long crank/hard start sounds more like fuel pressure.

There are no specs for charge output at idle, all tests are done at 1500-2000 RPM. What's the output then?

 

[adsm08]

Its a slow hard crank, lights dim down and it won't start with the lights on. This morning it was warmer than it has been and it fired right up. Giving it a bit of gas seems to help, but this is not only an IAC issue, and if that is contributing, its only by not getting enough power to the valve.

I didn't check output off idle.

 

[WJC97]

550 CCA seems low to me, but I don't know the specs. My old Escort 1.9 has 550 CCA battery, and I think my 2.3 Ranger is 575.

 

[adsm08]

550 CCA seems low to me, but I don't know the specs. My old Escort 1.9 has 550 CCA battery, and I think my 2.3 Ranger is 575.

Yeah, I'm thinking that spec for a 2.9 might be more in the area of 600 or 650, but I'm not sure. Like I said, in the last few weeks we've had temps much colder than anything I was considering when I bought the battery.

 

[strvger]

try getting a good quality marine/starting battery. should handle the truck's inactive periods much better than a standard car battery. that's what i've been using for over 3 years now and no complaints at all.

 

[adsm08]

Hmm, I'll have to think about that. I might just get a regular one again though because said inactivity is going to be coming to an end here in May when I get out of school and start looking for full time work again.