Odyssey AGM batteries seem to be basically a lead-acid type which has an even lower internal resistance than a Concorde (which is about half the internal resistance of a Gill of the same Ah / size).
So they should work fine, except that the load on the alternator will be that much greater following engine start, while it is bringing it up to the 14V or 28V bus voltage.
It will also be able to deliver more current so if you are using the original (not “NL”) Skytec starter (which according to data can draw ~350A) you will be putting more current through the starter relay, and through any other relay contact which the starter current happens to pass through. The later Socata TBs for example have a “ground power relay” whose normally-closed contact carries the starter current (a crap arrangement) and this contact is often found to be welded together, if a Skytec starter is fitted.
I have at least 5 odyssey batteries in my hangar
one sat in one of my biplanes waiting for an stc fuel pump (the old corvair membrane pump was verboten by the FAA) and with no charger on it started after 9 months and still held a charge. The only thing with these batteries is that you have to use their chargers, something about the voltage needed to keep them up, also if you use their chargers it will burn a non odyssey battery very quickly, ask me how I know. Dirt cheap, last forever but unfortunately as someone mentioned no good for big PT-6A engines since the voltage is not good enough on start leading to hot starts. No odyssey for my evolution.
I had my Odyssey battery PC625 for 5 years. Engine started even after -20C outside without charging.
I´m NOT using any smart charger since on the beginning I had some starting issues after leaving the charger in “maintain” mode.
Just charging during the flight, or using a regular charger read this here at here on using a smart charger "trickle
Sorry the post went to fast :-)
read this here
Those Odyssey batteries seem to require mind-boggling attention… My Concorde has just made 6 years, passed the load test fine, and I never charge it or recondition it between Annuals. I fly around once a week and it sits on a 28.0V bus the whole time when flying.
Peter wrote:
Those Odyssey batteries seem to require mind-boggling attention…
Not my experience. All AGM batteries have very little self discharge and Odyssey is at the top of the heap, quality wise. Ten years is typical life on motorcycles, in my experience, and the quality and power density is why they’ve become near universal on aircraft where regulation allows
Odysseys are also urburdened by the ridiculous Concorde terminal design, in which the terminal screws are threaded into soft copper! I use Concorde in my plane for lack of choice – it’s not STC’d for the plane but my IA doesn’t care. I’d love to never buy another aircraft battery from either of the two incumbent players.
Of course, as with any topic on aircraft there are those driven for their own reasons to make up a science project.
Peter wrote:
Those Odyssey batteries seem to require mind-boggling attention…
where when -2 C every one will believe the end of the wold is coming.
Peter wrote:
I spoke to Concorde at Friedrichshafen last year about this issue and they agreed – it is apparently a daily struggle for them. STCs are so often produced for marketing reasons.
My C172 had the Gill when I bought it and I replaced it with a Concorde at the first opportunity/need. That was 20 years ago and at that time general wisdom was that an STC was required so I paid the $100 for it. Today, I wouldn’t bother and would just install it as a minor alteration …. at least under N-reg. I’m sure most FAA A&P would sign it off as such. Agree that Concorde is now the gold standard and I’m completely satisfied. The only comment I would make is that they shouldn’t be left long in a fully discharged state with a load or they’ll sulphate, like any battery. At some point reconditioning won’t take. The mostly likely situation for this is when an aircraft is not run for a long period (> 2 weeks) and has something like a clock slowly discharging the battery. A battery tender is highly advisable in any case to keep the battery permanently topped-up & sulphate-free. Should get at least five years out of one. Nice thing about Concorde ICA is that their batteries are airworthy if they pass the load test (check the ICA brochure on-line for details). You can run the load test at home off your PC using a West Mountain Radio CBA incl test software, then recharge with your battery tender (recommend VDC BatteryMinder or CTEK).
I don’t know EASA rules, but they also seem to be much less restrictive on this too these days. Nonetheless, I have seen EASA “minor alteration” approvals for avionics which seem to indicate that EASA-land is interpreting a minor alteration to mean STC-light …. i.e. no real STC but still EASA paperwork. ;-)
Hi Peter, and anyone else with 24V batteries,
since my ship has a 24V battery too, and unit cost are high, Gill or not, what is your best source when the time comes for a new one ?
Post moved to existing thread.
The general view is that Concorde are much better than Gill, but cost more
