Terrence,
We have had amazing success with the PC680 model. In fact its almost the only battery we use anymore. We usually install a pair for a TSIO-550, four of them do a fantastic job with a Walter 601 installation and eight of the 680s spin up an Epic LT (PT6 67A) better than the two stock Concords. The only time have seen them wear out and get a little sluggish was when we went nearly a year starting a Walter turbine on only one pair. We didn't have the MCU linked properly to use both banks for start. Turbine readers please don't confuse what I'm saying with "high start". Frequently using 48volts for starting is not good for the start generator. We use both pairs of batteries but in parallel so only delivering 28v. As for the pair that got weak, they would still do the job but just not the way they did new. They did not fail suddenly by any means. In all other installations we have changed them every couple years as a precautionary measure. I have never seen one fail in any other way.

To my knowledge all of the 235s were fiberglass only. The carbon skins didn't start showing up until the IV was introduced.

If you would like information on where you can find great deals on the Odyssey batteries give me a call.

Matthew Collier
Fibercraft Inc.
541-419-5634
ivdiggs@gmail.com