Gill LT Battery

[hypertech]

On 3/25/2025 at 3:49 PM, Yetti said:

can we get a year date on these occurrences? and if you used a maintainer or not?

2024.  Yes, I keep it on a maintainer.

[PT20J]

I bought my Gill in 2021 and replaced it a little over a year later when it failed a capacity check. I always kept it on a Battery Minder. I was a little peeved with Gill because part of the reason I bought it was that Gill was advertising a rebate on it's website. When I went to fill out the paperwork for the rebate, I notice that it had expired. When I called Gill they refused to honor it although the person I spoke with admitted that he forgot to remove it from the website. I've got the battery in the hangar and keep it as an emergency spare. I top it off every couple of months with the Battery Minder.

Concorde's recommendation to not keep them on a maintainer continuously makes sense because any charging will release some hydrogen which will shorten then battery life.

I once talked to the owner of the company that makes Battery Minders and he told me that Concorde wanted some small change in voltage. He complied but the difference was so small that he didn't really think it would matter if you used a Gill minder on a Concorde or vice versa.

[Rick Junkin]

1 hour ago, PT20J said:

I once talked to the owner of the company that makes Battery Minders and he told me that Concorde wanted some small change in voltage. He complied but the difference was so small that he didn't really think it would matter if you used a Gill minder on a Concorde or vice versa.

@PT20J Skip, there's a bunch of flavors of BatteryMinders. Are you saying that the differences are small enough that any of them will work ok with any battery? I ask because I just switched from Gill LTs to Concorde RGs and replaced a 24V -S2 (Gill/Concorde flooded) with a -S5 (Concorde sealed RG). Did I waste my money?

I never did get around to buying the -S3 BatteryMinder that is supposed to be optimized for the Gill LT batteries. I used the -S2 that I had for the 243's that were originally in the airplane when I bought it. 

[PT20J]

1 hour ago, Rick Junkin said:

@PT20J Skip, there's a bunch of flavors of BatteryMinders. Are you saying that the differences are small enough that any of them will work ok with any battery? I ask because I just switched from Gill LTs to Concorde RGs and replaced a 24V -S2 (Gill/Concorde flooded) with a -S5 (Concorde sealed RG). Did I waste my money?

I never did get around to buying the -S3 BatteryMinder that is supposed to be optimized for the Gill LT batteries. I used the -S2 that I had for the 243's that were originally in the airplane when I bought it. 

I just asked what the difference was between the 24V Concorde and the 24V Gill Battery Minders because I was wondering if I needed to get a different unit when I switched from the Concorde to the Gill. I don’t remember the exact details but I came away believing that it wasn’t enough of a difference to matter.

[Ragsf15e]

5 minutes ago, PT20J said:

I just asked what the difference was between the 24V Concorde and the 24V Gill Battery Minders because I was wondering if I needed to get a different unit when I switched from the Concorde to the Gill. I don’t remember the exact details but I came away believing that it wasn’t enough of a difference to matter.

I thought the minders were specifically designed to always be attached to the battery “desulfating”… are you saying it’s better to leave it disconnected sometimes?

[PT20J]

17 minutes ago, Ragsf15e said:

I thought the minders were specifically designed to always be attached to the battery “desulfating”… are you saying it’s better to leave it disconnected sometimes?

Here is Concorde’s recommendation

https://batterymanagement.concordebattery.com/BatteryDocs/TB15.pdf

[Ragsf15e]

1 hour ago, PT20J said:

Here is Concorde’s recommendation

https://batterymanagement.concordebattery.com/BatteryDocs/TB15.pdf

Interesting, thanks.  I’ve had mine on a batteryminder continuously for ~5 years (two different airplanes) and felt the battery was doing well (based on passing the cap check each year), but maybe I’ll start using it less.  

[MikeOH]

1 hour ago, PT20J said:

Here is Concorde’s recommendation

https://batterymanagement.concordebattery.com/BatteryDocs/TB15.pdf

Exactly one of the two reasons I've never believed in continuous "maintenance" charging; the other is I'm paranoid about the, albeit small, fire risk.

[Hank]

@Ragsf15e, my third.Concorde is.now 3 or 4 years old, and none have ever been on a Minder because I don't own one. I generally get 7-8 years before replacing, although I've never had an IA tell me it has failed capacity testing (they just start cranking slowly and requiring charging).

[LANCECASPER]

9 hours ago, Rick Junkin said:

@PT20J Skip, there's a bunch of flavors of BatteryMinders. Are you saying that the differences are small enough that any of them will work ok with any battery? I ask because I just switched from Gill LTs to Concorde RGs and replaced a 24V -S2 (Gill/Concorde flooded) with a -S5 (Concorde sealed RG). Did I waste my money?

I never did get around to buying the -S3 BatteryMinder that is supposed to be optimized for the Gill LT batteries. I used the -S2 that I had for the 243's that were originally in the airplane when I bought it. 

You can send in your Battery Minder and they will convert from an S2 to S5 (or vice versa) for $75.

[EricJ]

3 hours ago, Hank said:

@Ragsf15e, my third.Concorde is.now 3 or 4 years old, and none have ever been on a Minder because I don't own one. I generally get 7-8 years before replacing, although I've never had an IA tell me it has failed capacity testing (they just start cranking slowly and requiring charging).

My previous Concorde was on a minder pretty much constantly, and lasted about 7-8 years, so I'm not sure it makes a significant functional difference.    FWIW, I was doing capacity tests on mine and it was always coming in at >90%, even when it started cranking slowly.   One day, not too long after doing a capacity test, it only turne the prop about a quarter turn and stopped in the middle of a compression stroke.    It did subsequently turn it enough to start, but after that I took it out and did another capacity check and it failed.   So I think starting to turn slowly is a better indicator of needing replacement than the capacity checks based solely on my experience, where it consistently passed capacity checks right up until failure.

[Rick Junkin]

3 hours ago, LANCECASPER said:

You can send in your Battery Minder and they will convert from an S2 to S5 (or vice versa) for $75.

The catch with this is the charger can't be more than 3 years old. Unfortunately I was outside that window.

[Rick Junkin]

11 hours ago, PT20J said:

Here is Concorde’s recommendation

https://batterymanagement.concordebattery.com/BatteryDocs/TB15.pdf

Now to determine the parasitic load on #1 with the new panel. My gut tells me it's in the noise.

[PT20J]

After some thought, I doubt it makes much difference whether you keep the battery on a minder or top it off once a month. What kills the batteries is sulfation and that will come from deep discharge cycles or leaving it discharged for a long time. In normal operation, the deepest discharge comes from starting. So, the more starts, the shorter the life. Leaving it sit in a discharged condition is also bad.

Float charging shouldn't do a lot of damage and it seems from reports here that people report about the same life from Concordes whether they keep them on a minder or not. These batteries are sealed and they shouldn't lose a lot of capacity unless they outgas hydrogen which only happens when a deeply discharged battery accepts a high charge rate causing an overpressure and outgassing.

If a float charge was really bad, flying the airplane would be bad for the battery also. 

If you want the battery to last the longest possible time, don't install it and top it off once a month  Otherwise, install it, don't abuse it and forget about it. 

[MikeOH]

One takeaway from the Concorde instructions is that a CONTINUOUS charge, even from a 'smart' minder charger may deplete the electrolyte; you don't fly the plane continuously so that just flying the plane doesn't constitute the same risk.

The other takeaway is that frequent flying (once a week) is plenty to stave off even the need for a battery minder.  What a surprise, flying often is good for the plane

[1980Mooney]

11 hours ago, MikeOH said:

Exactly one of the two reasons I've never believed in continuous "maintenance" charging; the other is I'm paranoid about the, albeit small, fire risk.

Many hangars (most? - especially municipally owned hangars) do not allow battery charging unless you are present.  Their insurance carriers are also paranoid about the risk…

https://www.wtae.com/article/hangar-fire-planes-damaged-westmoreland-county/61762122

https://www.wrdw.com/content/news/Airplane-hangar-burns-at-Barnwell-airport-damages-five-planes-445844383.html?outputType=amp

https://www.whiterivernow.com/2025/01/21/batesville-firefighters-respond-to-fire-at-airport-hangar/

https://www.lansingstatejournal.com/story/news/local/2024/09/02/fire-destroys-hangar-building-lansing-airport-capital-region-international/75045975007/

https://ktul.com/news/local/2-injuries-reported-after-fire-at-claremore-regional-airport-hangar-collapsed-aircrafts-removed-firefighters-damage-building-emergency-response-water-transported-hospital
 

https://bakersfieldnow.com/amp/news/local/firefighters-battle-blaze-at-tehachapi-airport-hangar-amid-heavy-snowfall-kern-county-california-fire-safety-hangar-

https://www.cbs19.tv/article/news/local/officials-investigating-private-hangar-catches-fire-at-east-texas-regional-airport/501-5119deed-d8ee-4417-8646-9b416d64633b

[LANCECASPER]

I put my battery minder on a timer so that it comes on twice a week for an hour

https://www.amazon.com/BN-LINK-Programmable-Weatherproof-Accurate-Christmas/dp/B07G9RK4VV/ref=sr_1_1_sspa?dib=eyJ2IjoiMSJ9.xmIgUacps-NYwm7JGZofOqdxSwNo6Hyd26Dx_6Jrl05bStha_OCuDfbY_RvejYhqRWW2LPusNY9r2_pFCcwf2HgJBmMG_ZkWstsG6HmCNGjaqpWqQm2GPDEMuAyzpYzY3qD-iqC0aceSUI128j_NoEdG6_lcjGzHSQartt57v1oPHObD_4Dc_5yuzmlg-ph0RMS9bKjOs8aMOG0KiTM5TPPrt5xKvVhUX9rhcj4uAacFKNOXzfvAW9kVP6MXEqYwVSlwRNj9NWFmM-msg_gfE47J2RwKwRraN_WAmvudUcM.Nd4fW-yo13J5Gr3TiJ3FeQBAYMcTrwOpGPCKuy3cnyc&dib_tag=se&keywords=BN-LINK%2B7%2BDay%2BOutdoor%2BHeavy%2BDuty%2BDigital%2BProgrammable%2BTimer&qid=1743095660&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1

[Grant_Waite]

Funny, I just pulled my gill sealed battery today because it seems to not hold a charge anymore. Bought a Concorde xc hopefully it’ll last more than 3 years in Florida. I didn’t keep the other battery on a minder but the previous owner did. I fly typically 1-3x a week so use shouldn’t have been a factor. 

[Hank]

5 hours ago, Grant_Waite said:

Funny, I just pulled my gill sealed battery today because it seems to not hold a charge anymore. Bought a Concorde xc hopefully it’ll last more than 3 years in Florida.

You'll be pleased. I get 6-7 years on my Concordes here in Sweet Home Alabama, just a Mooney Hour from KECP, Panama City. No Minder used, and you fly much more often than I ever have.

[Grant_Waite]

9 hours ago, Hank said:

You'll be pleased. I get 6-7 years on my Concordes here in Sweet Home Alabama, just a Mooney Hour from KECP, Panama City. No Minder used, and you fly much more often than I ever have.

Good, it should work just as well for me then. For whatever reason gill does not seem anywhere close to the quality of Concorde. I’ll be curious to see if the plane turns over faster. It wasn’t slow to begin with just wouldn’t hold a charge. Alternator might be due for overhaul if the battery doesn’t work. Loose wire could be an issue but I’ll start with the most obvious. Surprised the gill lastest 3 years with the long inactivity it would sit before I bought the plane.