How long should a Concord RG35a last?

[Speed Merchant]

I got stranded yesterday. My wife and I flew to Okeechobee for lunch. Got back in the plane turned the key and nothing just a little click from the starter solenoid. The battery voltage read 12.3 on my JPi. So I thought that that was adequate voltage for the starter. I thought I lost the starter, but I didn't . I need a new battery. I put a new Concord RG35A I. About 21/2 years ago. Is this a typical life span for this battery?

[Z W]

I consider anything longer than 3 years to be a bonus.  2.5 years is a little short.

Might consider checking your battery connections for corrosion and tightness, all the way from the battery to the starter, and the main ground cable in particular.  A bad connection can make an otherwise functional battery seem weak.

[ArtVandelay]

That’s been my experience, I think you will only get extended life if you put it on a trickle charger.

[Hank]

I don't own a trickle charger, but the Concorde's usually last 6-7 years in my C.

P.S.--I use the -XC (?) for the additional cold cranking amps.

[Igor_U]

Hmm,

I am on my second Concorde in my F and both were used for about 7-8 years. I always use trickle charger and good capacity (90%) was confirmed at the annual with capacity check done by my IA. I would say 2.5 years is a way too short.

 

[GeeBee]

I have AGMs in my boat (3 of them) and my airplane. Trickle charge is the key to long AGM life.

[pkellercfii]

I got over seven years from my first Concord before I euthanized it. By that time, its loaded voltage had fallen slightly, although it could still start the engine, which is what I care about from the battery in my dual alternator K model. I’m currently at ~4.5 years on my second Concord, and it’s going strong. Both batteries have been generally kept on BatteryMinders when at home in the hangar.

 

—Paul Keller

’89K@TTA

 

[PT20J]

The problem with quantifying battery life is twofold.

First, what defines end of life: Failure to pass capacity test, of failure to crank? The former will occur long before the latter. 

Second, is how the battery was treated. What temperatures was it stored at? How many times has it been run completely down and how long did it sit discharged. Has it been used for a lot of short flights where it may not get fully recharged? Is it kept on a battery minder?

Concorde's FAQ says typical life is 3-5 years.

[jetdriven]

The first Concorde lasted seven years, but the second one lasted barely 2, we found a bad diode in the alternator and the AC output, probably fried it. 

[Speed Merchant]

3 hours ago, Z W said:

I consider anything longer than 3 years to be a bonus.  2.5 years is a little short.

Might consider checking your battery connections for corrosion and tightness, all the way from the battery to the starter, and the main ground cable in particular.  A bad connection can make an otherwise functional battery seem weak.

Thanks the connections are fine. The battery is just shot.

[Speed Merchant]

3 hours ago, Hank said:

I don't own a trickle charger, but the Concorde's usually last 6-7 years in my C.

P.S.--I use the -XC (?) for the additional cold cranking amps.

The battery before this one lasted 7 years. 

[Speed Merchant]

3 hours ago, Hank said:

I don't own a trickle charger, but the Concorde's usually last 6-7 years in my C.

P.S.--I use the -XC (?) for the additional cold cranking amps.

Thanks

[Alan Maurer]

Going on five. years in my R and no trickle charger and most flights under one hour. Airplane always in hangar and not left out. 

Alan

[Shadrach]

1 hour ago, Speed Merchant said:

I got stranded yesterday. My wife and I flew to Okeechobee for lunch. Got back in the plane turned the key and nothing just a little click from the starter solenoid. The battery voltage read 12.3 on my JPi. So I thought that that was adequate voltage for the starter. I thought I lost the starter, but I didn't . I need a new battery. I put a new Concord RG35A I. About 21/2 years ago. Is this a typical life span for this battery?

That’s unacceptably short service in my opinion. I would expect a Concorde to last a minimum of 4 years for a maintained battery. My last one lasted more than twice that before falling below 80%.

[Mac80]

I like to charge my battery up a  couple days or sooner before a flight. I had been told from an alternator shop that had repaired mine that having a  discharged battery is very hard on alternator life span and I had repaired a couple way to often.

Since I have been pre charging my battery the alternator, except a field wire connector breaking, has not needed replaced and my last Concorde RG-15M was replaced at 8.6 years in 2023.

I had to used a trickle charger by attaching yellow plug and jump. I stopped several years back when we lost power at the hangar and my set up severely discharged my battery.

[LANCECASPER]

13 hours ago, Speed Merchant said:

I got stranded yesterday. My wife and I flew to Okeechobee for lunch. Got back in the plane turned the key and nothing just a little click from the starter solenoid. The battery voltage read 12.3 on my JPi. So I thought that that was adequate voltage for the starter. I thought I lost the starter, but I didn't . I need a new battery. I put a new Concord RG35A I. About 21/2 years ago. Is this a typical life span for this battery?

I think you just got a bad Concorde. They usually last much longer. It may have been discharged all the way down once during its life which is hard on the battery or maybe sat in the shelf awhile before you bought it.

Next time you're at an air show where Concorde has a booth I would walk up and introduce yourself (the name LoPresti still carries a lot of weight ) and let them know "what great success you've had with their batteries and how you've always recommended them  . . .  except for this last one. Are they not made as well as they once were? I'd like to be able to recommend them to pilots I know, but . . " 

They are a good company and I bet they do something for you, a Visa gift card which they sometimes give at airshows. They want to know.

[aviatoreb]

I had a pair last for 12 years in my rocket, on trickle charge.

[Fly Boomer]

15 minutes ago, aviatoreb said:

I had a pair last for 12 years in my rocket, on trickle charge.

Did those two batteries stay "in sync"?  I'm using a 24-volt BatteryMINDer, and I'm suspicious that the two batteries in series may not be getting equal treatment.

EDIT:  Disregard last transmission.  I just realized that your batteries are in parallel.

[Fritz1]

I have two 6 year old Concords on a battery minder in parallel, they tested 90% at last check, hope to get another 2 years out of them, think the key to long service life is not to run them down and keep on trickle charger when at home

[EricJ]

Another thing that matters is the regulated voltage during operation.     A friend was going through Concordes too quickly, and ultimately swapped out the ancient regulator (this is on a Cherokee) and now he gets consistent ~14V rather than the 13-ish he was getting before.   This seems to be helping.

[aviatoreb]

3 hours ago, Fly Boomer said:

Did those two batteries stay "in sync"?  I'm using a 24-volt BatteryMINDer, and I'm suspicious that the two batteries in series may not be getting equal treatment.

EDIT:  Disregard last transmission.  I just realized that your batteries are in parallel.

As far as I know they did.  Well until the end - on the 12th year they were showing strong signs of age - slow turning over of the prop etc.  Until then they were testing out great.

[laytonl]

I changed out My first 28v Concorde RG after 6 years thinking it must be end of life.  Never tested it or had it on trickle charge.  The battery sat in the hangar for another year or so and one day my son called and asked if I still had that battery because he had a dead battery in a plane he was flying.  I told him he could try the old battery but it would probably need charging first.  As sons are apt to do, he disregarded my recommendation to charge the battery and just put it in the other airplane and started the airplane.  The old battery stayed in that airplane for two more years before it died.  Those batteries last a long time.
 

My citabria has a 14v Concorde RG and after 6 years I move it to the Mooney tug.

Lee

[MikeOH]

Over six years on the first Concorde (installed by PO), about 3 1/2 on the new one; just capacity tested over 90%.

NO trickle charger, either (OH, THE HORROR). Hangared, warm climate, flown frequently (twice a week) may contribute.

[Stephan Kablitz]

Hi Speed Merchant,

do you have a readout of the buss voltage? Sometimes voltage regulators go astray and finally fail. We got ours overhauled by Don Maxwell recently and he set the buss voltage to 28.8 for the Concorde AGM type 24V battery. So your VR should regulate to precisely 14.4V. AGM batteries need slightly higher charging voltage than lead-acid types and the VR must be configured accordingly. Having a buss voltage a little to low will result in the final charge to be substantially below maximum. The target buss voltage is unfortunately a function of the battery temperature, so ideally we would have to adjust the VR in winter to an ever so slightly increased buss voltage and readjust when it becomes warmer.

If you don't get this right - as probably most people including me do - the trickle charger will help to "fill up" what the VR didn't finish. Otherwise the AGM battery will be tortured at too low charging levels and give up early.

[Fly Boomer]

On 6/7/2024 at 10:23 AM, Stephan Kablitz said:

We got ours overhauled by Don Maxwell recently and he set the buss voltage to 28.8 for the Concorde AGM type 24V battery.

I spoke to a Concorde engineer when I was building a GPU.  He said use 28.2 or 28.3 for both the GPU and the voltage regulator.