Time for a new battery?

[jrwilson]

My daughter accidentally bumped the overhead light switch getting something out of the plane when we were on a trip and we came back to a dead battery.  Luckily we were able to get a jump and the battery took a charge from the alternator on the 5 hour flight back home.  Started up fine after getting gas and taxiing back to the hangar.  But, since the battery was completely drained, is it best to get a new one?  It is a Concord RG-35 battery.

I saw the related thread about wiring a timer to that switch like Don did...Awesome idea!  My wife also suggested just disabling that light since we never use it...

[toto]

That very same switch cost me almost 3AMU. (Don't ask.) Concorde battery was about 18mos old, had to be replaced. 

Why they don't have the dome light wired into the master, I have no idea. 

[Niko182]

Id keep the battery and see if itll hold a charge. If so keep it. If not get a new one, but you might get lucky. Doesnt hurt trying to give it a shot.

[jrwilson]

11 minutes ago, toto said:

That very same switch cost me almost 3AMU. (Don't ask.) Concorde battery was about 18mos old, had to be replaced. 

Why they don't have the dome light wired into the master, I have no idea. 

Well I've gotta ask now!  Why?!  How?!  Batteries aren't that much! 

[smwash02]

20 minutes ago, jrwilson said:

Well I've gotta ask now!  Why?!  How?!  Batteries aren't that much! 

You're living in 14V land. I believe all '80 and newer (I don't recall the start date) use 28V and the battery is nearly $700. Add in the rental car, flights home, flights back, maybe a hotel, mechanic, etc. Adds up quick.

I did the same thing back in Colorado a few months ago. I asked my mechanic and he said if I don't do it more than a time or two usually it works out okay. I'm sure I took a few months off of its life but it's been 4+ months and has acted just fine since with many starts.

[jrwilson]

Just now, smwash02 said:

You're living in 14V land. I believe all '80 and newer (I don't recall the start date) use 28V and the battery is nearly $700. Add in the rental car, flights home, flights back, maybe a hotel, mechanic, etc. Adds up quick.

I did the same thing back in Colorado a few months ago. I asked my mechanic and he said if I don't do it more than a time or two usually it works out okay. I'm sure I took a few months off of its life but it's been 4+ months and has acted just fine since with many starts.

Yeah, that could get pricey.  I got lucky and someone was there with a jumper.  I think my battery (1984 231) is only about $350.

[steingar]

I accidentally drained the battery on my Cherokee.  One of the gyros had been removed from service, and I think it was the noise of that thing that reminded me to shut down the master.  Master got left one, battery drained.  I charged it right back up and kept flying it for years.

[rbridges]

I'm no expert, but I did some googling after my IA left the master on after the annual.  Same as @steingar, my battery bounced back and ran for a few more years until I replaced it (age 6).

From what I've read, the battery should recover if it hasn't been too long and the plates aren't irreversibly sulfated.

Edited February 17, 2020 by rbridges

[jrwilson]

cool, thanks for the replies.  Looks like I'll give it a chance and see how it does.

[ArtVandelay]

Id keep the battery and see if itll hold a charge. If so keep it. If not get a new one, but you might get lucky. Doesnt hurt trying to give it a shot.

Problem is you won’t be able to trust it. It will be fine if you fly often, but if you go on a cross country trip and leave it for a week, and maybe it’s cold, it may not have full capacity and you are stuck.

[jrwilson]

Just now, ArtVandelay said:

Problem is you won’t be able to trust it. It will be fine if you fly often, but if you go on a cross country trip and leave it for a week, and maybe it’s cold, it may not have full capacity and you are stuck.

Dang it, you just reached my level of paranoia!  now I need to get a new one.  $350 for peace of mind i guess isn't too bad...

[smwash02]

8 minutes ago, jrwilson said:

Dang it, you just reached my level of paranoia!  now I need to get a new one.  $350 for peace of mind i guess isn't too bad...

Referring back to 28V v 14V land, you can go to AutoZone/Walmart/etc grab a jump kit and be on your way in an hour. Ask me how I know... Grab one with the built in air pump and you solve multiple problems at once.

I'm building a lithium version out of RC batteries for mine that will be able to plug into the side port because it's not as simple with 28V. There's commercially available ones for an AMU or so, but it's about $150 in parts and would be a fun weekend project.

[DonMuncy]

2 hours ago, toto said:

Why they don't have the dome light wired into the master, I have no idea. 

I think the thought process is that one often needs a light to unload the plane after a flight. Not a bad thought, but it has cost many batteries. The shut-down timer is an easy fix.

[DonMuncy]

39 minutes ago, ArtVandelay said:

Problem is you won’t be able to trust it. It will be fine if you fly often, but if you go on a cross country trip and leave it for a week, and maybe it’s cold, it may not have full capacity and you are stuck.

It is not hard to do a capacity check on the battery (OK, you do have to have the equipment). If it checks out good, no worries. If not, replace it.

[tmo]

2 hours ago, smwash02 said:

I'm building a lithium version out of RC batteries for mine that will be able to plug into the side port because it's not as simple with 28V. There's commercially available ones for an AMU or so, but it's about $150 in parts and would be a fun weekend project.

Do share when done, please.

[orionflt]

3 hours ago, ArtVandelay said:

Problem is you won’t be able to trust it. It will be fine if you fly often, but if you go on a cross country trip and leave it for a week, and maybe it’s cold, it may not have full capacity and you are stuck.

not true, but I would take it to a shop and have the capacity checked IAW Concords ICA http://concordebattery.com/otherpdf/5-0171.pdf. if it passes then its good. if it doesn't, then you have the possibility of having what Art was saying could happen.

Brian

[steingar]

4 hours ago, ArtVandelay said:

Problem is you won’t be able to trust it. It will be fine if you fly often, but if you go on a cross country trip and leave it for a week, and maybe it’s cold, it may not have full capacity and you are stuck.

I've been keeping my batteries on cheap tenders for years.  That battery on my Cherokee lasted until I sold it, which I think was 6 years later.  I've had the same battery in my Mooney for I think 5 years.  I've never had a problem.

[ArtVandelay]

I've been keeping my batteries on cheap tenders for years.  That battery on my Cherokee lasted until I sold it, which I think was 6 years later.  I've had the same battery in my Mooney for I think 5 years.  I've never had a problem.

Did you completely drain it like the OP did?

[N9405V]

How old was it to begin with? If over a couple of years, I’d go on a mend replace it.


Sent from my iPhone using Tapatalk

[carusoam]

Summary...

1) The lights that are not turned off by the master switch... we’re a convenience for unloading the plane after dark...

2) Balance that inconvenience with the dead battery...   

3) A decent charger is a great place to start... Everyone has selected their favorite based on cost and other things... I use a BatteryMinder that matches my Specific Concorde battery...

4) Ultimately you know the exact health of your battery when following the standard capacity test...

5) the standard capacity test will check for the voltage it achieves and see how many electrons it can hold as it gets drained over the time of the test... it has a set of specs to make to be called a winner...

6) the importance of passing the test Depends on what you are using your plane for... and how many spare batteries you have in the system...

7) I’m a fan of flying in IMC and carrying a pair of big batteries... 

PP thoughts only, not a mechanic or CFI...

Best regards,

-a-

 

[81X]

19 hours ago, steingar said:

I accidentally drained the battery on my Cherokee.  One of the gyros had been removed from service, and I think it was the noise of that thing that reminded me to shut down the master.  Master got left one, battery drained.  I charged it right back up and kept flying it for years.

This is funny. I did the same exact thing for the same exact reason with my Cherokee when the TC was out for service.  Not the first time I hand propped the airplane, but the first time for leaving the master on!  
 

That battery kept chugging away for some time after that incident. 

[steingar]

16 hours ago, ArtVandelay said:

Did you completely drain it like the OP did?

I've no idea, I've no equipment to measure electrical charge and no wisdom on how to use it if I did.  Battery wouldn't turn over the airplane, and nothing electrical worked.

[carusoam]

@steingar...

Digital multi-meters are so inexpensive...

Learn to measure volts, ohms, and sometimes amps...

It will make a fun weekday project...

 

Owning a DMM... you will save at least one car battery too...

Best regards,

-a-

[59Moonster]

On 2/18/2020 at 7:30 AM, steingar said:

I've no idea, I've no equipment to measure electrical charge and no wisdom on how to use it if I did.  Battery wouldn't turn over the airplane, and nothing electrical worked.

Pull the battery and bring it to an auto shop like autozone or carquest, napa. They will have one on hand. Heck they may even let you borrow it.

[Jerry 5TJ]

On 2/17/2020 at 12:12 PM, DonMuncy said:

I think the thought process is that one often needs a light to unload the plane after a flight. Not a bad thought, but it has cost many batteries. The shut-down timer is an easy fix.

I use one of these as the overhead cabin lamp.  Forget to switch it off and you’re out 3 AAA batteries. And the plane still starts.