Sealed battery vs lead-acid w/Battery Minder

Anthony

Anthony

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Anthony
My work and travel schedule sometimes takes me away from the ability to fly the Tiger for a month at a time. I've found the battery drained a few times, especially in the winter, which I know is very hard on lead acid batteries, and their lifespan. There is an electric clock fuse which I now remove if the plane is going to sit for more than a week, which I think previously has caused the battery to drain.

What maintenance, if any, is required for a Concorde sealed battery if it is going to sit for a month in the winter? Being sealed, do they need any type of Battery Minder? Also, the with the lower cost of a new Gill lead-acid battery (if needed) I could buy a Battery Minder, and just keep it on the plane in the weeks I don't fly. So my question is which is the better route? Sealed or not?

Thanks.
 
From strictly a chemical point of view, I'd put the battery minder on the sealed battery. It will still self-discharge if left alone.
 
I can't even remember what battery I put in the Free Bird, but it is hooked up to a cheap battery minder. Cherokees are really susceptible to low battery power in winter, as the battery is in the aft of the aircraft under the passenger seat, so there is a lot of resistance as the power goes to the starter. We've never been unable to start the airplane since we put in the tender, whereas low battery was a constant problem before.
 
Anthony said:
So my question is which is the better route? Sealed or not? Thanks.
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No question - go with the Concord. That being said, I'm not sure that the "problem" has been resolved. Seems there are three possibilities. 1.) The battery itself is shot, if so a new Concord is the way to go. 2.) There is still a small current leak that drains the battery. If so, no matter what battery you put in, you will still have a problem. I'll agree that the electric clock is a drain and MAY cause a fully charged battery to go dead, however I have my doubts. Still think it is worthwhile to find out if there is a constant drain on the battery. 3.) The charging system isn't doing its job so the battery isn't getting a full charge. If true you will still have problems with a new battery.

I've had a Concord on the Cherokee for 5+ years, no BatteryMinder on it and I've never had it go dead enough that it wouldn't start the engine, even after a month, in winter. Turns a bit slow at 30F, but still starts. Since you have a hangar, putting a BatteryMinder on it while sitting there is a good idea, won't hurt, only helps.

Don't know how old the Gill is, maybe it is worth it to just replace it and continue the troubleshooting.

Gary
 
Gary, I'm not sure either. I flew the plane yesterday. Of course it started great as the battery was fully charged. It started the second time after I flew it for about 20 minutes. I flew it another half hour or so and shut it down. We'll see if it starts the next time.
 
A good desulficating automatic battery tender can be left on indefinatley.




Free Bird? :rockon:
 
Geico266 said:
A good desulficating automatic battery tender can be left on indefinatley.




Free Bird? :rockon:
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Michael won the plan at Osh one year, thus "FREE" bird.

Anthony have you been pulling the breaker on the clock since I saw you at Wings?
 
Anthony said:
Yep. We'll see if it starts later this week.
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If it doesn't, you have a problem. First, the warmer it is the faster the battery will self-discharge. A good battery with nothing draining it should still have close to a full charge after a month in the winter. Charge it then pull the cable off one pole and check the voltage periodically for two or three weeks. If it's discharging the battery needs to be replaced. Otherwise look for the load. Concord sealed are the best. Don't even think about a sealed Gill. As for flooded cell, I've never had a problem with the Gill. If you get a charger, make sure it's a Battery Minder aviation model unless you get one of the little 750ma ones and check the charging profile to make sure it doesn't maintain voltage higher than the temp corrected gassing voltage before dropping to float mode. This isn't such a big deal with a flooded cell since you can add water.
 
Update:

Well it cranked right up this morning, very strong, and immediately. Spun the prop really well. OAT was 47F.

Thanks to Gary S. for the over the phone troubleshooting. Keep your fingers crossed! :)
 
My non-sealed lead acid battery spends most of the winter frozen solid. Once warmed (it is in the cowl with the preheater) it turns the starter as well as in July. No loads on it when the master is off.
 
Anthony said:
Update:

Well it cranked right up this morning, very strong, and immediately. Spun the prop really well. OAT was 47F.

Thanks to Gary S. for the over the phone troubleshooting. Keep your fingers crossed! :)
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Glad it started! Still not sure that the problem is solved. Since the battery tested OK under load, maybe time to do some further investigation of the charging system and potential for a current drain. From what you described, your in-flight cruise voltage seemed low, but I'm not sure what the specification should be for a Tiger.

Gary
 
Gary said:
Glad it started! Still not sure that the problem is solved. Since the battery tested OK under load, maybe time to do some further investigation of the charging system and potential for a current drain. From what you described, your in-flight cruise voltage seemed low, but I'm not sure what the specification should be for a Tiger.

Gary
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It was showing 12.9v most of the time in cruise yesterday. When I started it, and during taxi it was 13.2v. I really don't know what the JPI is measuring though, battery output or alternator output. A few years ago, I asked my mech (when I was in CO) what the actual charging voltage was and he said the JPI was reading about a volt low. I'll see if I can get a definitive answer on what it is measuring.

I still somewhat suspect a potential intermittant drain and/or charging issue.
 
12.9 is definitely low for cruise. That's about a full battery with no support....:(

Did you measure it when you put it away?
 
bbchien said:
12.9 is definitely low for cruise. That's about a full battery with no support....:(

Did you measure it when you put it away?
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No, I did not, but I'll measure it when I can get up there tomorrow. However, my mech did say the JPI monitor was reading 1 volt low, so if that is true, then it would be consistantly between 13.7v - 13.9v.
 
Anthony said:
No, I did not, but I'll measure it when I can get up there tomorrow. However, my mech did say the JPI monitor was reading 1 volt low, so if that is true, then it would be consistantly between 13.7v - 13.9v.
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OK - BUT - How do we know if the JPI is reading low OR is it reading correctly? May be worthwhile to check "what somebody says". Isn't that hard to measure voltage between the bus and ground, just need a voltmeter (which you have) and a couple of alligator clips.

Gary
 
Gary said:
OK - BUT - How do we know if the JPI is reading low OR is it reading correctly? May be worthwhile to check "what somebody says". Isn't that hard to measure voltage between the bus and ground, just need a voltmeter (which you have) and a couple of alligator clips.

Gary
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When the airplane is running the alternator?
 
First, check voltage right at the battery which should be 12.9v fully charged. Second flip on the master and avionics master and see what the JPI says. It should be a half volt or maybe even one volt lower than the battery depending on what is drawing current. Third, run the engine and you should see around 14 volts. With the alternator on line you are looking at buss voltage and it shouldn't read low at all. For a sealed Concord, the charging (buss) voltage should not be below 13.75 even in 100* weather.
 
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