Will a failing auto battery have trouble cranking a motor before it completely dies?

yes, dirty terminals WILL cause slow starter rotation or low amperage to starter, clean and replace as necessary. a dead cell or weak battery will cause same problem, and a bad starter armature can cause these symptoms, most likely cables and terminals, start there first, then check battery, most auto part stores do this for free. and if none fix it try replacing starter. good luck!

A failing battery will struggle to start the car. However, there are other things that can cause that too, such as very cold temps, A failing alternator can fail to charge a perfectly good battery too.

Corrosion on the terminals can reduce the contact a battery needs to provide a full charge to the starter.

Absolutely. Automotive battery *load tests are the best way to determine reserve amperage capacity of the battery. Amperage spins starter motors not volts.

Yes, that is a symptom.

5-6 years old is another problem. Batteries don't usually last that long. Best to go ahead and replace it now than wait for it to leave you stranded.

It could be a bad battery, a bad starter, or corroded connections. I would clean the connections first. If that does not work, take your battery to a battery shop and have them test it. If the battery is good, you need to test your starter.

You may want to replace the corroded terminals. As for the battery, take a volt meter and test the battery. It should be around 12.4-12.6v. If not, replace that too.

yes it could be a weak battery or the terminals need to be cleaned ! it can,t turn over very good if the terminals are dirty !

Sure will...all of the above are factors.