Concorde RG-35AXC

JohnAJohnson

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JohnAJohnson
I installed a Concorde in my 177B (Lycoming O-360) three years ago and for the last month or so, it has turned the engine over slowly. Today it almost stranded me, but after resting it for an hour, it barely turned the engine over, but it started.

Back home, on the bench...
The battery shows fully charged, at 13.2 VDC across the terminals. Swapped it with my friend... It wouldn't spin his IO-360 either, but his battery (also an RG-35AXC) spun my engine fine. So I put my battery on a charger, and it proceeded to tell me it was completely charged. I tried two other chargers and neither would charge it because they saw it as completely charged. I put on a manual charger and shot it with 6 Amps for four hours (at 16.5 VDC). It still had no capacity and wouldn't turn over my truck or airplane engine. By the way, the voltage drops to 5 VDC (at the terminals) while cranking.

When flying, my Plane Power Alternator and Zeftronics Regulator crank out an honest 13.8 VDC. And when hangared, my BatteryMinder 12248-AA-S2 Battery Charger/Maintainer is always connected.

I bought the best battery I could find, ensured my plane had the best alternator and regulator available, and when not flying, kept it on the best charger/maintainer that I could find, and this $300 battery lasted only 3 years. I am more than disappointed and am looking for suggestions or ideas on how I can do better, or if any of my actions have caused the early failure. BTW, the bolts were not over torqued during installation - no cracks, no leaks.
 
I installed a Concorde in my 177B (Lycoming O-360) three years ago and for the last month or so, it has turned the engine over slowly. Today it almost stranded me, but after resting it for an hour, it barely turned the engine over, but it started.

Back home, on the bench...
The battery shows fully charged, at 13.2 VDC across the terminals. Swapped it with my friend... It wouldn't spin his IO-360 either, but his battery (also an RG-35AXC) spun my engine fine. So I put my battery on a charger, and it proceeded to tell me it was completely charged. I tried two other chargers and neither would charge it because they saw it as completely charged. I put on a manual charger and shot it with 6 Amps for four hours (at 16.5 VDC). It still had no capacity and wouldn't turn over my truck or airplane engine. By the way, the voltage drops to 5 VDC (at the terminals) while cranking.

When flying, my Plane Power Alternator and Zeftronics Regulator crank out an honest 13.8 VDC. And when hangared, my BatteryMinder 12248-AA-S2 Battery Charger/Maintainer is always connected.

I bought the best battery I could find, ensured my plane had the best alternator and regulator available, and when not flying, kept it on the best charger/maintainer that I could find, and this $300 battery lasted only 3 years. I am more than disappointed and am looking for suggestions or ideas on how I can do better, or if any of my actions have caused the early failure. BTW, the bolts were not over torqued during installation - no cracks, no leaks.


I think some battery tenders are killing them. I have the same battery, in a Cardinal, and have gotten more than 8 years out of it. I don't used a tender at all and for the last three years it has endured three month periods of no flying and no battery tender.

Its also been run down dead twice in 8 years

All I do every year is pull it, wash it in the sink with dawn dish soap or similar top charge it then put it in the refrigerator till I'm don'e with the annual.
 
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I think some battery tenders are killing them

I think you might be on to something. I always wondered what happens when you continuously shoot high voltage across a battery to desulfate it, when it doesn't need to be desulfated. I usually fly at least once a week and think I might forego the charger/maintainer altogether and see what happens. New battery is on order, so I'll be right back where I started three years ago, sans charger/maintainer and of course, $300.
 
Is that a tender specific for that battery? When I did some casual looking around, seemed like different batteries needed different inputs. I am using a non-aviation on my Gill and I know it will cook it, if I leave it on for extended times and especially if I leave it going when the ambient is >75-80F°.
 
Is that a tender specific for that battery?

It is. The BatteryMinder 12248-AA-S2 is hawked specifically for the Concorde AGMs and is priced accordingly at $190. Very discouraging to see some of my friends using $25 Battery Tender Juniors with great results year after year. I guess I am the guy P. T. Barnum was thinking of with his famous quote.
 
Unfortunately, the S2 is specifically designed for flooded Gill batteries.

The Concorde AGM needs the S3.

And, yes.....it does make a difference.

Looking at the BatteryMINDer and other websites, the -S2 is certainly for the Gill. My 12248-AA-S2, purchased in 2010, was (at the time) for the Concorde AGM, and the face is different than the S2s sold today. Matter of fact, in big letters in the lower left corner, mine says, "NOT for use with GILL LT Series or ODYSSEY Aircraft Batteries".

So I'm not sure what BatteryMINDer is up to, but changing applications on a part number is at best confusing. Today, it looks like the 12248-AA-S5 is the model specifically for the Concorde AGMs, but I don't think I'll be buying any more of their products till I figure out exactly what in my battery failed, and why.
 
Heard back from Concorde. It appears I've undercharged the Concorde for an extended period of time and it has sulfated with the resultant high internal resistance. Expectantly, it won't accept anything from the charger cause it thinks the battery is fully charged.

Concorde also suggested I contact BatteryMinder for their free upgrade from a -S2 to a -S5.

My aircraft system is also a tad low at 13.8 volts and I'd like to bump it up to 14.0 minimum. If you have a Zeftronics Voltage Regulator (R15100 Rev A), can you tell me what your bus voltage is?
 
Heard back from Concorde. It appears I've undercharged the Concorde for an extended period of time and it has sulfated with the resultant high internal resistance. Expectantly, it won't accept anything from the charger cause it thinks the battery is fully charged.

Concorde also suggested I contact BatteryMinder for their free upgrade from a -S2 to a -S5.

My aircraft system is also a tad low at 13.8 volts and I'd like to bump it up to 14.0 minimum. If you have a Zeftronics Voltage Regulator (R15100 Rev A), can you tell me what your bus voltage is?



That is where my aircraft voltage is with an old vibrator type voltage regulator and the battery is still going after 8 years. :dunno: Again, no battery tender/minder.
 
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I am dealing with exactly the same issue on my C205. Concorde RG-35AXC is 2 1/2 years old and dying. Religious use of S5 BatteryMINDer. Very disappointed. Charging system appears to be functioning properly. Spent a while on the phone with Skip, the Concorde tech support guy but no smoking gun was identified.

James
 
Guess I'll buy the battery tender junior then. Thanks guys.
 
Have a 5 year old Concorde RG35AXC in my Cherokee and have never had a charger on it and it works perfectly. Buss Voltage is 14.1 if I recall Correctly. I fly it an average of every two weeks, however there are times when it is 4 or 5 weeks between flights. Always starts great.
 
My aircraft system is also a tad low at 13.8 volts and I'd like to bump it up to 14.0 minimum. If you have a Zeftronics Voltage Regulator (R15100 Rev A), can you tell me what your bus voltage is?

Your aircraft maintenance manual will state the voltage that it needs to be set to. Some aircraft use a different voltage than typical (for whatever reason).

That said, most 12v systems are configured for 14.0-14.2
 
check the voltage under load. With an assistant crank e starter while the meter is hooked to the battery and try to see how much the voltage drops. More than 4 volts is a possible bad cell. A battery load meter will do the same thing automatically, but they are $300+. Eiher way it sounds like the battery is toast. :(
I run the battery minder for one week a year, at annual.
 
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