Slow start with new battery?

[mires]

I dropped in a new Deka AGM battery the other night but I'm not quite getting the results I expected. The main thing I wanted when purchasing this battery was fast starting. The battery it replaced was a 4 year old Duralast that was starting pretty slow, and I was really expecting the Deka to just crank right up, but it doesn't seem to be any faster than the old battery. I'm just looking for any input as to what the problem may be. Suggestions?
The deka is a 9A78DT by the way. Plenty of CCA!

 

[Antichrist]

Have you checked all the connections to make sure they are solid with no corrosion and are tight, including cable to lug connections at battery, starter, starter to ground and ground to battery?
Also, slow cranking with toast a starter so if it was really slow for a long time then the starter could not be 100%.

 

[mires]

Have you checked all the connections to make sure they are solid with no corrosion and are tight, including cable to lug connections at battery, starter, starter to ground and ground to battery?
Also, slow cranking with toast a starter so if it was really slow for a long time then the starter could not be 100%.

I will go check those things now. I cleaned the terminals before I installed the new battery so I know they are clean but I'll check everything else. I can't say the starting before was REALLY slow. It just never fired right up like I think it should. Could the alternator have anything to do with it?

 

[Martyn]

Lots of variables here.

Are you saying the starter is not cranking the engine fast enough, or are you saying the engine has to be cranked for a while before it starts?

 

[Antichrist]

Good point, slow cranking and slow starting are two entirely different things. I was thinking in terms of slow cranking.

 

[mires]

Lots of variables here.

Are you saying the starter is not cranking the engine fast enough, or are you saying the engine has to be cranked for a while before it starts?

The starter is not cranking the engine fast enough. It's hard to explain and even understand myself because I admittedly do not have much experience with electrical systems. This will probably offer the best explanation as to what I am getting at. When I first start my truck in the morning, it takes 2-3 seconds to start. After driving it 15 minutes or so and I stop to get gas or something, when I go to restart it, it fires up almost before the key is turned all the way. Fires up really fast! I was under the assumption that with the battery upgrade, it would start fast like that all the time. Could something be wrong or was I just expecting too much out of my new battery?

 

[mires]

Good point, slow cranking and slow starting are two entirely different things. I was thinking in terms of slow cranking.

You're correct Antichrist. Slow cranking is what we're talking about here. Thank god! I don't need any slow starting issues :sombrero:

 

[wrcsixeight]

I sometimes use all 3 of my batteries to start my engine. If it is fully cold, it cranks very fast but does not start instantly, but within a second.

If my engine is hot, it starts with the slightest engagement of the starter.

A cold engine is going to take longer to start, always. Also a recently stopped vehicle's battery is going to have a surface charge. This surface charge will have the battery voltage up a little higher, so it will initially crank a little faster. A vehicle that has sat overnight will have a battery whose surface charge has dissipated.

Clean the starter wire connections, and the battery to engine ground, and that's all you can really do for your starter. You can try using a thicker wire to the starter.

A lighter weight oil might help slightly. Go from a 10w 30 to a 5w 30 or a 0w 30. 0 weight oils are synthetic.

You should check the voltages with the engine running to determine if the alternator is charging at a high enough voltage, also put the battery on a charger overnight just to make sure it is fully charged. Alternators are not really good at bringing a battery to 100%