Two dead Optima's

[wcmoore]

I have a 2002 K2500 w/Duramax.150k miles. In short, got in the truck ,turned the key and no crank. After checking the alternator, the brushes nearly gone and two nice grooves where they were riding decided to change it even though the output was normal and the diodes ck good. Replaced a Positive cable from Rt side Battery to starter due to corrosion from origional Delco Batts leaking. I put two new batteries in and it cranks normal except the delay in the voltage rise to normal output is not there. The two optimas were 3 yrs 4 mo old and had no warning that they were being drained. They should have lasted longer than that so would like to know if there is something else I need to check?
Thanks...

[DarylB]

Load test each battery. Those Red tops have an 84mo warranty with 3yr free replacement. if they went out at 40mos if they warranty is correct you ought to be able to get replacement(s) for next to nothing.

[wcmoore]

I checked the voltage when turning the ignition to crank and it dropped off to 2-3volts. Took them to the local parts store and used their load tester and indicated bad battery on both. I put them on a charger overnight also and could not recharge them. They indicated 12.6 V no load but no current. The previous time I drove the truck, it obviously cranked fine or I would have noticed. There must have been a major drain on them to kill the that quick like a stuck relay or something similar.