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Battery Cap Tester

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jonlaury

Joined: 06 Nov 2006
Posts: 336

Posted: Thu Jul 11, 2013 8:01 am Post subject: Battery Cap Tester

Bob,

Last October, when I left my Pitot heater on overnight, my PC680 got pulled down to 7.5v and I mentioned the event in another post. At that time, you said you were building a batt cap tester to sell on the AEC. 



Is it about to launch?



After charging, I've noticed that my PC680 drains from 13 to 11.6v over two weeks of sitting. My car battery doesn't drain that much even with phantom loads of the ECU, clock and anything else that I'm not aware of. So I was going to fab a poorman's cap checker unless you've got something that will save me the trouble.



Thanks,

John

Do Not Archive

klehman(at)albedo.net
Guest

Posted: Fri Jul 12, 2013 3:22 am Post subject: Battery Cap Tester

I believe HobbyKing sells a $20. ish dollar device that will integrate 

whatever discharge you choose to put on the battery.

Ken

do not archive



On 11/07/2013 12:01 PM, jonlaury wrote:

 	  Quote: 	
		   



 Bob,

 Last October, when I left my Pitot heater on overnight, my PC680 got pulled down to 7.5v and I mentioned the event in another post. At that time, you said you were building a batt cap tester to sell on the AEC.



 Is it about to launch?



 After charging, I've noticed that my PC680 drains from 13 to 11.6v over two weeks of sitting. My car battery doesn't drain that much even with phantom loads of the ECU, clock and anything else that I'm not aware of. So I was going to fab a poorman's cap checker unless you've got something that will save me the trouble.



 Thanks,

 John

nuckolls.bob(at)aeroelect
Guest

Posted: Fri Jul 12, 2013 6:45 am Post subject: Battery Cap Tester

At 11:01 AM 7/11/2013, you wrote:

 	  Quote: 	
		  



Bob,

Last October, when I left my Pitot heater on overnight, my PC680 got 

pulled down to 7.5v and I mentioned the event in another post. At 

that time, you said you were building a batt cap tester to sell on the AEC.



Is it about to launch?



After charging, I've noticed that my PC680 drains from 13 to 11.6v 

over two weeks of sitting. My car battery doesn't drain that much 

even with phantom loads of the ECU, clock and anything else that I'm 

not aware of. So I was going to fab a poorman's cap checker unless 

you've got something that will save me the trouble.


	


   Hi John,



   Funny you should mention that. I've been on an archeological

   dig on the workbench and uncovered a nicely fabricated

   po' boy's cap checker sent to me for troubleshooting.

   It was receipt of that project that launched the software

   based timer/cap-checker project. Paul got the software up

   to a beta release state. It goes on the same ECB as the

   uC based wig-wag controller. I need to stuff a board,

   program a chip and see if it all comes together.



   Sounds like you're needs are pretty immediate. Just the

   pitot heater? Sounds like the the master was left on

   and more 'stuff' than pitot heater was loading the

   battery. In any case, an over-night load of that magnitude

   certainly extracted 99%+ of the battery's contained energy.



   How old was the battery when this event occured?



   What are you using to charge the battery? Is it a smart

   charger with a bulk/top-off/sustain profile?



   This accelerated self-discharge doesn't sound good

   but it MIGHT be that your charger isn't topping

   the battery off.  Does it still crank the engine?

   Have you conducted a cranking load test (how many

   amps delivered after 15 seconds loaded down to

   9 volts)?



   If it's still cranking the engine, then the battery

   should top off in flight with a bus of 14.4 to 14.6

   volts. But if the OCV drops that fast, then it's

   almost a certainty that the battery is crippled.



   I've moved the po' boy's battery cap checker to

   the front of the bench but its going to be awhile

   before it's in a practical state of utility for

   you. If you're flying this battery, you need some

   faster data.  Clip a 55w head-lamp bulb across the

   battery and come back in 2 hours to check the

   voltage.



http://tinyurl.com/kgkxw3l



   If it's not at 11.0 volts or above, the battery

   is toast.



   Another reader suggested this battery test fixture

   from Hobby King . . .



http://tinyurl.com/q2sv4xl



   It's designed to test an array of li-ion cells in

   a model . . . not well suited to your task and is

   certainly not outfitted to load your battery in

   concert with your endurance loads. Further, reviews

   of this device are in the toilet.



   Bob . . .

klehman(at)albedo.net
Guest

Posted: Fri Jul 12, 2013 7:57 am Post subject: Battery Cap Tester

this is the hobbyking item I was thinking of.

Up to 60 volts and 130 amps.



http://www.hobbyking.com/hobbyking/store/__10080__turnigy_130a_watt_meter_and_power_analyzer.html

Ken

do not archive



 	  Quote: 	
		   

<nuckolls.bob(at)aeroelectric.com>
	


 	  Quote: 	
		   

 At 11:01 AM 7/11/2013, you wrote:

 >

<jonlaury(at)impulse.net>
	


 	  Quote: 	
		   >

 >Bob,

 >Last October, when I left my Pitot heater on overnight, my PC680 got 

 >pulled down to 7.5v and I mentioned the event in another post. At 

 >that time, you said you were building a batt cap tester to sell on

the AEC.
	


 	  Quote: 	
		   >

 >Is it about to launch?

 >

 >After charging, I've noticed that my PC680 drains from 13 to 11.6v 

 >over two weeks of sitting. My car battery doesn't drain that much 

 >even with phantom loads of the ECU, clock and anything else that I'm 

 >not aware of. So I was going to fab a poorman's cap checker unless 

 >you've got something that will save me the trouble.

 

    Hi John,

 

    Funny you should mention that. I've been on an archeological

    dig on the workbench and uncovered a nicely fabricated

    po' boy's cap checker sent to me for troubleshooting.

    It was receipt of that project that launched the software

    based timer/cap-checker project. Paul got the software up

    to a beta release state. It goes on the same ECB as the

    uC based wig-wag controller. I need to stuff a board,

    program a chip and see if it all comes together.

 

    Sounds like you're needs are pretty immediate. Just the

    pitot heater? Sounds like the the master was left on

    and more 'stuff' than pitot heater was loading the

    battery. In any case, an over-night load of that magnitude

    certainly extracted 99%+ of the battery's contained energy.

 

    How old was the battery when this event occured?

 

    What are you using to charge the battery? Is it a smart

    charger with a bulk/top-off/sustain profile?

 

    This accelerated self-discharge doesn't sound good

    but it MIGHT be that your charger isn't topping

    the battery off.  Does it still crank the engine?

    Have you conducted a cranking load test (how many

    amps delivered after 15 seconds loaded down to

    9 volts)?

 

    If it's still cranking the engine, then the battery

    should top off in flight with a bus of 14.4 to 14.6

    volts. But if the OCV drops that fast, then it's

    almost a certainty that the battery is crippled.

 

    I've moved the po' boy's battery cap checker to

    the front of the bench but its going to be awhile

    before it's in a practical state of utility for

    you. If you're flying this battery, you need some

    faster data.  Clip a 55w head-lamp bulb across the

    battery and come back in 2 hours to check the

    voltage.

 

 http://tinyurl.com/kgkxw3l

 

    If it's not at 11.0 volts or above, the battery

    is toast.

 

    Another reader suggested this battery test fixture

    from Hobby King . . .

 

 http://tinyurl.com/q2sv4xl

 

    It's designed to test an array of li-ion cells in

    a model . . . not well suited to your task and is

    certainly not outfitted to load your battery in

    concert with your endurance loads. Further, reviews

    of this device are in the toilet.

 

 

 

    Bob . . .

rparigoris

Joined: 24 Nov 2009
Posts: 780

Posted: Fri Jul 12, 2013 8:04 am Post subject: Battery Cap Tester

Hi Group 

 	Here's one slick tool that no home should be without: 

 	http://www.hobbyking.com/hobbyking/store/__10080__Turnigy_130A_Watt_Meter_and_Power_Analyzer.html 

 	You can  keep it alive with an aux battery if required. I use a 4 AA holder from Rat Shack that has a built in switch. 

 	You can data log watts in or out. I have used it to charge and measure capacity of batteries ranging from a 50mA NiMh to 4 in series 200 amp lead acid deep discharge. 

 	The above is OK quality, but not as nice as Astroflight Whatt Meters: 

 	http://www.astroflight.com/electronics/watt-meters.html 

 	It's whatt, not watt meter. 

 	Hobby King thus far has been OK to deal with. If they show 0 in stock, you have to wait before they will ship until they do another run. That's the way they operate, they get orders, then build. You can go on their site and put something on a wishlist, then when they make a production run you will get an E-Mail they have stock. Shipping, their cheap kind is cheap, but slow (OK by me most of the time). I think they offer other modes of shipping. 

 	Or buy a Whattmeter, they ship from USA, probably same day for a little more than double the price. 

 	The only difference I find, is the Whatt meter is not a directional tool, run a load from a battery through the meter it will begin to accumulate watts, now begin to charge through the meter and it will accumulate watts the same. The Turnigy will only log in one direction. I tend to like the quirk of the Whatt meter. 

 	Ron Parigoris 

 	     [quote][b]

jonlaury

Joined: 06 Nov 2006
Posts: 336

Posted: Sat Jul 13, 2013 8:02 am Post subject: Re: Battery Cap Tester

[quote="nuckolls.bob(at)aeroelect"]At 11:01 AM 7/11/2013, you wrote:

 	  Quote: 	
		  

(snip).....



   How old was the battery when this event occured?



   What are you using to charge the battery? Is it a smart

   charger with a bulk/top-off/sustain profile?



   This accelerated self-discharge doesn't sound good

   but it MIGHT be that your charger isn't topping

   the battery off.  Does it still crank the engine?

   Have you conducted a cranking load test (how many

   amps delivered after 15 seconds loaded down to

   9 volts)?



   If it's still cranking the engine, then the battery

   should top off in flight with a bus of 14.4 to 14.6

   volts. But if the OCV drops that fast, then it's

   almost a certainty that the battery is crippled.



   I've moved the po' boy's battery cap checker to

   the front of the bench but its going to be awhile

   before it's in a practical state of utility for

   you. If you're flying this battery, you need some

   faster data.  Clip a 55w head-lamp bulb across the

   battery and come back in 2 hours to check the

   voltage.



http://tinyurl.com/kgkxw3l



   If it's not at 11.0 volts or above, the battery

   is toast.



  



   Bob . . . 	




Bob,



The battery was installed about 4-5 months before the pitot drain down occurred. It was being maintained by a Schumacher XC-10, set for 'Gel cell' per Schumacher recommendation after 'AGM' setting was pushing over the Odyssey max voltage of 15.5v.



When the battery is topped off at about 13.5 volts, it readily spins the 6cyl, 350 ci Franklin with 10.5 : 1 compression through about 4, 5-7 sec start attempts before getting tired and at rest voltage starts sagging.



Yesterday, after 24 hours on the XC-10, votage was at 14.67v. 

After disconnect and about 1.5 hrs, it was at 14.04v. 

I'll check it todayand I'll do the lamp test across the terminals too, and report. 



Thanks,

John

nuckolls.bob(at)aeroelect
Guest

Posted: Sat Jul 13, 2013 8:30 am Post subject: Battery Cap Tester

Bob,



 The battery was installed about 4-5 months before the pitot drain down occurred. It was being maintained by a Schumacher XC-10, set for 'Gel cell' per Schumacher recommendation after 'AGM' setting was pushing over the Odyssey max voltage of 15.5v.



 When the battery is topped off at about 13.5 volts, it readily spins the 6cyl, 350 ci Franklin with 10.5 : 1 compression through about 4, 5-7 sec start attempts before getting tired and at rest voltage starts sagging.



 Yesterday, after 24 hours on the XC-10, votage was at 14.67v.  After disconnect and about 1.5 hrs, it was at 14.04v. 



    That's not a 'bad' value. There is a period of time

    after charger disconnect until the battery terminal

    voltage falls to its nominal resting value. There

    are small variations between lead-acid technologies

    but they'll generally fall into this range of values. 



 [img]cid:.0[/img]



   These values are accurate only after a considerable 'resting

   interval' for removal of either a charger or a load . . .

   a 6-hour rest before measurement is probably reasonable.



   The fact that it will deliver 4 cranking cycles suggests

   that the battery is not seriously degraded . . . but a new

   we tested a new 18 a.h. battery on a high compression

   competition engine at 6 or 7 robust start cycles.



   Sounds like your battery is wounded but still serviceable.



   The self-discharge rate seems excessive . . . a reasonable

   hypothesis is that it's a symptom of the 'wounding'. Unless

   your design goals dictate that the battery support a

   e-bus for several hours, this battery may service your needs

   for some time.



  	  Quote: 	
		  I'll check it todayand I'll do the lamp test across the terminals too, and report. 	


   Good move. Have you established an endurance load requirement

   for how you use your airplane?



 

   Bob . . .

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nuckolls.bob(at)aeroelect
Guest

Posted: Sat Jul 13, 2013 2:07 pm Post subject: Battery Cap Tester

Hi John,

 >

 >  Funny you should mention that. I've been on an archeological

 >  dig on the workbench and uncovered a nicely fabricated

 >  po' boy's cap checker sent to me for troubleshooting . . .



 



   Made a few drill chips this afternoon and got all the

   hardware mounted on the proof of concept Bat Cap Checker.



         



 [img]cid:.0[/img]



 [img]cid:.1[/img]



   All the holes have been plugged with screws. It's

   time to stuff the board and wire it up.



   This version is configured to run a battery down using

   the chosen load . . . in this case 3x55w lamps.

   When the test terminates, the lights will go out,

   the relay will drop and connect a charger to the

   battery for replenishment. Touching meter leads

   to BAT- and MTR+ will yield a voltage reading

   between 0 and 5 volts.  5 volts = 5 hours of

   endurance.



 

   Bob . . .

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billp(at)wwpc.com
Guest

Posted: Sat Jul 13, 2013 2:44 pm Post subject: Battery Cap Tester

jonlaury

Joined: 06 Nov 2006
Posts: 336

Posted: Sun Jul 14, 2013 8:21 am Post subject: Re: Battery Cap Tester

 	  nuckolls.bob(at)aeroelect wrote: 	
		  Bob,



...snip

 Yesterday, after 24 hours on the XC-10, votage was at 14.67v.  After disconnect and about 1.5 hrs, it was at 14.04v. 



    That's not a 'bad' value. There is a period of time

    after charger disconnect until the battery terminal

    voltage falls to its nominal resting value. There

    are small variations between lead-acid technologies

    but they'll generally fall into this range of values. 



 [img]cid:.0[/img]



   These values are accurate only after a considerable 'resting

   interval' for removal of either a charger or a load . . .

   a 6-hour rest before measurement is probably reasonable.



   The fact that it will deliver 4 cranking cycles suggests

   that the battery is not seriously degraded . . . but a new

   we tested a new 18 a.h. battery on a high compression

   competition engine at 6 or 7 robust start cycles.



   Sounds like your battery is wounded but still serviceable.



   The self-discharge rate seems excessive . . . a reasonable

   hypothesis is that it's a symptom of the 'wounding'. Unless

   your design goals dictate that the battery support a

   e-bus for several hours, this battery may service your needs

   for some time.



  	  Quote: 	
		  I'll check it todayand I'll do the lamp test across the terminals too, and report. 	


   Good move. Have you established an endurance load requirement

   for how you use your airplane?



 

   Bob . . . 	


Bob,



2 hour 75 watt (parts on hand) load result:



Begin test voltage: 13.6 (down .44 from previous day)

End test voltage , lamp connected: 12.4v

After 2 hour rest: 12.97v



 All-electric airplane 97% VFR

Electrical power: 60a alt, 40a stby alt, 18ah PC 680

Minimum electrical load at 75% power = 15.5a (load decreases slightly at lower power setting) EFI 3.5a, 1 Ignition 2.5a, 1 pump 7a, EFIS 1a, Xpdr 1.5a



John

nuckolls.bob(at)aeroelect
Guest

Posted: Sun Jul 14, 2013 11:17 am Post subject: Battery Cap Tester

Bob,



2 hour 75 watt (parts on hand) load result:



Begin test voltage: 13.6 (down .44 from previous day)

End test voltage , lamp connected: 12.4v

After 2 hour rest: 12.97v



   Sounds like your battery's capacity is not seriously

   hurt.



All-electric airplane 97% VFR

Electrical power: 60a alt, 40a stby alt, 18ah PC 680

Minimum electrical load at 75% power = 15.5a (load decreases slightly at

lower power setting) EFI 3.5a, 1 Ignition 2.5a, 1 pump 7a, EFIS 1a, Xpdr 1.5a



   With dual power sources I think the risks

   for continued use of this battery are low.

   I'm at a loss to explain your observation of

   accelerated self-discharge.



   Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Sun Jul 14, 2013 3:21 pm Post subject: Battery Cap Tester

 	  Quote: 	
		  

 Bob,



 2 hour 75 watt (parts on hand) load result:



 Begin test voltage: 13.6 (down .44 from previous day)

 End test voltage , lamp connected: 12.4v

 After 2 hour rest: 12.97v

 	




    Hmmmm . . . according to data right from the horse's 

    mouth, a 75 watt load on a new PC680 should take

    it down to 10.00 volts in about 2.2 hours. This corresponds

    to a current of about 9A.



 [img]cid:.0[/img]



   I'm pretty sure that Watts and Amps are CONSTANT values applied

   by a 'smart' load . . . which resistors and lamps can only approximate.

   Nonetheless, the fact that you were still above 12.4 volts after two hours

   raises some questions.  At first blush it appears your battery

   is in REALLY good shape.



 



 

   Bob . . .

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jonlaury

Joined: 06 Nov 2006
Posts: 336

Posted: Mon Jul 15, 2013 7:53 am Post subject: Re: Battery Cap Tester

Bob



I'll try it again to see if I get something different.



Why is it that Odyssey comes up with a 9 amp load (at) 12v making 75W?

I thought you could take to the bank the relationship of volts, amps and watts.  9 amps x 12v should be 108W in my perfect world.



J  hn

nuckolls.bob(at)aeroelect
Guest

Posted: Mon Jul 15, 2013 8:50 am Post subject: Battery Cap Tester

At 10:53 AM 7/15/2013, you wrote:

 	  Quote: 	
		  



Bob



I'll try it again to see if I get something different.



Why is it that Odyssey comes up with a 9 amp load (at) 12v making 75W?

I thought you could take to the bank the relationship of volts, amps 

and watts.  9 amps x 12v should be 108W in my perfect world.




	




    EXCELLENT QUESTION!  I'll try to study it

    further and see if I can deduce their

    methodology. Discharging the battery at

    constant watts and constant amps for a

    non-linear event will produce some disparity

    of values . . . but I can't see that it

    would be that big.



   Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Mon Jul 15, 2013 9:28 am Post subject: Battery Cap Tester

--> AeroElectric-List message posted by: "jonlaury" <jonlaury(at)impulse.net>



 Bob



 I'll try it again to see if I get something different.



 Why is it that Odyssey comes up with a 9 amp load (at) 12v making 75W?

 I thought you could take to the bank the relationship of volts, amps and watts.  9 amps x 12v should be 108W in my perfect world.



 

     Here's an excerpt on PC680 data from another Hawker-Enersys

     document . . .



 

 [img]cid:7.1.0.9.0.20130715121715.020f01f8(at)aeroelectric.com.0[/img] 



    . . . and the companion plot



 [img]cid:7.1.0.9.0.20130715121715.020f01f8(at)aeroelectric.com.1[/img] 



   This plot is consistent with tabular data and with your

   test results. I must conclude that the earlier posting was excerpted

   from erroneous data.



   The fact remains that your battery seems to be in good shape . . .

   which still leaves us with questions about the observed self-discharge

   rate.



 



 

   Bob . . .

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jonlaury

Joined: 06 Nov 2006
Posts: 336

Posted: Mon Jul 22, 2013 4:22 pm Post subject: Re: Battery Cap Tester

 	  nuckolls.bob(at)aeroelect wrote: 	
		  --> AeroElectric-List message posted by: "jonlaury" <jonlaury>



 Bob



 I'll try it again to see if I get something different.



 

   Bob . . . 	




After a night on the charger and a few hours rest, started at 13.0 volts and after 2 hours of 75 watt draw, disconnected lamp and measured 12.0



The relatively high day to day discharge turns out to be attributable to having left my pilot side NC headset (battery bus) on. The LED indicator was facing the seat back.

nuckolls.bob(at)aeroelect
Guest

Posted: Tue Jul 23, 2013 7:53 am Post subject: Battery Cap Tester

 	  Quote: 	
		  After a night on the charger and a few hours rest, started at 13.0 

volts and after 2 hours of 75 watt draw, disconnected lamp and measured 12.0



The relatively high day to day discharge turns out to be 

attributable to having left my pilot side NC headset (battery bus) 

on. The LED indicator was facing the seat back.


	


   Aha! A credible explanation. Good work!



   Bob . . .

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