Odyssey PC925 battery lifetime

On the recent Bahamas trip I had a slow cranking start after a quick (~ 30 minutes) fuel stop. I thought it was the battery so bought a small garden tractor battery to run in parallel with the Odyssey. I never made that connection since the next morning the engine started normally. I blew off the battery causal factor and thought it might be the starter.

I had another slow cranking episode just prior to going over water.

After I got home, I called Sky Tec and inquired if the starter could have a heat related issue. The answer was no. Yesterday I followed their trouble shooting guide and got a starter input voltage of 10.1 volts. The battery voltage was 10.7 volts which suggests a battery issue according to their guide.

I took the battery out and had it checked at a local auto parts store and their assessment was that the battery was marginal.

My mechanic also tested the battery and he felt it was ok.

Since the battery was installed in June 2006, I decided to assume that it was degraded and ordered a new PC680 from Bohannon Battery. If it is degraded, then it lasted 5.0 years.

I am guessing that included over 600 flight hours but have to check that number.

Alternator voltage is around 14.3 volts.

I just bought a charger for my Odyssey battery that is supposed to extend
its life. OMAX-12A-1B. http://www.odysseybattery.com/chargers.html
The distributor indicated that the PC680 was good for at least 5 years if
it is kept in condition (hence the trickle charger). In my RV-6 I had a Concorde
battery and would replace it every 3 years. I fly my airplane most
every week and have seen no battery degradation in three years (of which
2 1/2 years flying). My voltage after sitting for two weeks is still over 12V.

Today I took the PC925 back to O'Reillys (formerly Checker) and had them test the battery on the larger battery tester (not the hand held).

The result was that the battery is good. Who ya gonna believe?

I already ordered a PC680 and will do a voltage test while starting once I get the Skytec NL starter (with the PC680).

Five years is adequate. That may become my replacement cycle for Odyssey batteries.

PC-680

Did you get 5 years without any battery tender?

Just discussed this today with a hangar neighbor. We both only got 2+ years out of our -680s. I now have a tender on it most the time and hope for more like the 5 yrs. I've heard is often attained.

Was surprised at the short life of the first one. Charging system checks out. Weather here is fairly mild. Who knows....

To the best of my knowledge I have NEVER used my Battery Minder (Model #12112) on this battery. I was thinking about that today and wonder if I were to use it for a few days every few months if the sulphination reduction would extend the life.

I just checked and my engine rebuild was after I put the PC925 in the plane. Since the plane was not flown for several months, I may have used the Battery Minder then.

Ron Lee said:

To the best of my knowledge I have NEVER used my Battery Minder (Model #12112) on this battery. I was thinking about that today and wonder if I were to use it for a few days every few months if the sulphination reduction would extend the life.

Click to expand...

Just for grins, try putting the Battery Minder on the battery for a week or two, and just let it do its thing------then have the battery re-tested.

Might prove to be interesting.

Smart guy Mike. I gave the PC925 to my mechanic who put his battery Tender (I Think ) on it. So it had about 2.5 days on that between when I tested it with a handheld tester at O'Reilys (marginal outcome) and when it was tested today on their larger tester (result good battery).

Of course this is not consistent testing. If the PC680 and the Skytec NL starter work ok, then he gets the PC925 battery. He likes batteries like my dog likes to play in a mulch pile.

I am not complaining about five years. I think the "service life" is 3-10 years.

What engine and what starter do you have

Hi
I had this problem with my io540 with a skytec ls. I had some trouble to crank the engine when hot probably because of the higher compression.
I change the battery for another 925 and no change. I change the starter with a skytec nl and problem solve. I look and sound like a really bettere starter.

Lan vinh do
Rv10 c-gmce

I had the same problem with my 2-yr-old PC-680. Cranking got slower and slower. Got a battery resistance tester from Harbor Freight and tested a couple of PC-680's as well as other automotive batteries and found my battery at 11 milliohms and another newer -680 at 7 mOhms... I wondered why only after only 2 years such high resistance, so I asked Enersys for an answer. They replied that I could "rejuvenate" the battery by draining it down to ~10V (measured open circuit) using a 50-100W headlight bulb and then charging overnight at 14.7V, and repeat this process 5 times.

Well, I started at 11 milliohms and after 5 discharge/recharge cycles got 8.2 milliohms. Definite improvement. Cranks pretty much like new again. My ND alternator charges at 14.4V and I fly a couple times a week, so it seems that should be enough to keep the battery happy, but apparently that's not good enough.

Ironically I was doing a search to look for discussions on Odyssey battery life. On my latest coast to coast trip I had a few sluggish starts even after quick fuel stops. It's been in the plane since 2004 or 2005 so it sounds like 7-8 years is pretty good!

I had this problem in a car that I built. Running a PC680 turning a 302 ci engine. I fought with it for about a year with the problem getting steadily worse. Replaced starter, battery cables all the way from the battery to the starter, starter solenoid, considered upgrading to a PC925 because I thought maybe it was related to the high engine compression, but then kept coming back to the fact that it worked fine for three years, why is it now a problem? I then bypassed my battery cutoff switch and all was well and has been for the past year.

My point is, my experience is very similar to Paul's a couple of months ago where it looks like the connection to the starter was slightly loose and carbon built up to the point that it finally would not crank when hot, and sounds much like yours and others that I have heard of. Check the connections, including any crimped or soldered joints. Keep in mind that any switch or connection in the system produces a slight voltage drop. With time, these can degrade and increase the voltage drop and chaninging the battery and/or starter will not fix the problem.

HTH

Tim