SO a rebuild did it? How's your battery now? I've been through 3 in 4 years, and when I bought it after 3 years on the road, my car had already had the OEM battery replaced, so at least 4 in 7+ years.
Is it possible that a f'd alternator could be killing the batteries prematurely?
Yes I am back to 14.0 volts at idle!
Battery is great, I LOVE my ODYSSEY Battery!
2 Batteries in 1
Odyssey batteries combine in one box the characteristics of two separate batteries. It can deep cycle (be recharged) as well as provide enormous cranking power.
Military Grade
Only Hawker Odyssey batteries are based on the same battery technology offered by Hawker to the military for aircraft and tank batteries. Odyssey batteries are of military grade and have endured rigorous tests that demonstrate their overall ruggedness and exceptional tolerance of mechanical abuse.
Superior cranking and fast charge capability
The 5 second cranking power of Odyssey batteries is double to triple that of equally sized conventional batteries, even when the temperature is as low as - 40 C. Also, with simple constant voltage charging (alternator or independent charger), there is no limitation on the inrush current, so the user is assured of a fast charge.
•Drycell Battery
•Without Metal Jacket
•12 Volt
•55 Ah @ 10hr rate
•850 CCA
•950 MCA
•1400 Cranking Amps for 5 Seconds
•130 Minute Reserve Capacity
•Cycle life @ 77 F 400 at 100% DOD
•-40 F to 140 F Temperature Range
•Made in the USA
Features:
•3 to 10 year service life, when properly maintained.
•99.9% pure lead providing minimal plate corrosion
•Explosion proof
•Corrosion proof
•2 to 3 times the cranking power of equivalent size battery
•Spill and leak proof
•Superior vibration resistance
•Fully Charged out of the box
•When fully charged can be stored for up to 2 years at 77 F
•May be installed on its sides at any angle without sacrificing performance attributes
•Military grade version of the Hawker Genesis
•2 Year Full Powersports Warranty
•Made in the USA
These cars are very hard on batteries, after having 3 in 3 years I went with the ODYSSEY battery. The Mazda5, having the electric steering, doesn't help things either. As I monitor the voltages when driving and turning on different features like defroster, or high beams, etc. I notice that the voltage does drop for 2 seconds until the PCM reacts and readjusts the voltage regulator. So maybe the fact that the system is a bit lagging it puts additional stress on the battery.
In my case, my alternator would work when engine was hot, but not work when it was cold. So if you had a failing alternator, and did a lot of short trips where the alt was not getting hot enough to charge, that would put a lot of stress on battery as well. However if it was not charging, you would/should have the "BATT" indicator light illuminated on the dash.
After a week of certified repair, I will go ahead and perform an autopsy on the old reg/brush assembly and see if I can locate the failure.