Angier wrote:

I installed two Odyssey PC545 batteries during the build in May 2008.
First flight was back in February and about a month ago I thought I sensed a little less cranking power on startup.
On start on the last flight, the prop would not pass through the compression stroke so I waited a bit, hit the starter again and even through there was a bit of hesitation, motor started normally. So my uneducated guess is that these batteries are tired and have lost a lot of there cranking power. They have always been maintained on an Odyssey Battery Minder and with a check on a battery tester, they're still in the green. Anyway, two new PC545 will be installed today.
Everybody else having good experience with their Odyssey batteries?


Angier,
Five years is pretty good service life for batteries,  but generally, the Odesseys should do  better, especially since you've kept them in good condition/lightly used. I have two independent electrical systems on my IV-P, using two PC 680s each. I replaced the pair of batteries I bought in 2006 last year, and was planning to replace the 2008  batteries at this condition inspection. Both sets still crank the airplane well, but this is one area where I'm "second guessing," so I could  use some factual information as well. For example, is there a valid test for power available, etc.

One other note. These batteries require a higher charging voltage than "regular" batteries. Be sure your regulator is adjusted to the specs called for in the Odessey literature. Can send same if needed, but also available on-line.

Bob