Matronics Email Lists :: View topic - Alternator Putting out MAX Current

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Alternator Putting out MAX Current

Matronics Email Lists Forum Index -> Yak-List

View previous topic :: View next topic

Author Message

ChangDriver

Joined: 15 Sep 2007
Posts: 266

Posted: Fri Aug 30, 2013 5:05 pm Post subject: Alternator Putting out MAX Current

I have a B&C alternator and voltage regulator on my CJ.  Today when running the engine at takeoff power, the alternator started putting out 35 amps (max current).  Bus voltage is regulated at 28.8 volts.  I have never seen it put out so much current.  No lights on, etc.  Just normal stuff.  It typically runs around 5 amps or so.  



I have new batteries installed so that is not an issue.  Bus voltage is 23.8 with engine not running.



Any ideas??

lothar.m(at)tzler.at
Guest

Posted: Fri Aug 30, 2013 11:14 pm Post subject: Alternator Putting out MAX Current

I have an B&C alternator too in my Yak52 (excuse my austrian english). The 

problem I see is: The load current of the alternator or generator depens 

always from the currently use for the board net and the currently condition 

of the batteries (two 12V in serie). By the way, I have the problem to need 

every two years new batteries. Every time one off the twos is in high 

(inside) resistenz condition. I think the problem is that at the beginning 

the two new batteries are not 100% on the same load condition. Originally 

there was only one battery. Consequentially during load in the plan, the 

lower one is always let me say a halve volt below the nominal 28,8:2=13,9V 

however the other 14,9V. Probaly the lower one with the time will get high 

impedanz. This is because the Voltage controller does not now two batteries! 

It only can regulate the nominal 28,8 V.

About your problem I mean the electronic voltage controller from the B&C 

alternator has only one power(ampere) regtulator and that is the max 

permitted power. This is an disadvantage compared with the original 

Generator controlling.

Your problem is the current battery condition. If you check the current with 

the same speed half hour later, you will see the current at sam conditions 

is lower, because in the mean time.



Have a nice day



Lothar Matzler

-----Ursprüngliche Nachricht----- 

From: ChangDriver

Sent: Saturday, August 31, 2013 3:05 AM

To: yak-list(at)matronics.com

Subject: Alternator Putting out MAX Current






I have a B&C alternator and voltage regulator on my CJ.  Today when running 

the engine at takeoff power, the alternator started putting out 35 amps (max 

current).  Bus voltage is regulated at 28.8 volts.  I have never seen it put 

out so much current.  No lights on, etc.  Just normal stuff.  It typically 

runs around 5 amps or so.



I have new batteries installed so that is not an issue.  Bus voltage is 23.8 

with engine not running.



Any ideas??





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=407798#407798

ChangDriver

Joined: 15 Sep 2007
Posts: 266

Posted: Sat Aug 31, 2013 2:16 am Post subject: Re: Alternator Putting out MAX Current

Thanks for the reply.  I have two brand new 12 v batteries in series to make the 24 v system.  The current is RPM dependent.  At idle there is no current.  As RPM increases, the current rises.  Like at 1200 rpm 4 amps, 1500, 12 amps, 2000, 22 amps, at t/o power of 2400 rpm 35 amps.

mikecavanagh1(at)hotmail.
Guest

Posted: Sat Aug 31, 2013 8:11 am Post subject: Alternator Putting out MAX Current

Voltage regulator is not working, check your connections, but your throttle is your voltage regulator until it is fixed.  Do not fly until you figure it out.  Does the B&C have a built in regulator, if so it may need to be replaced. Talk to B&C and he will help you.

On Aug 31, 2013, at 5:16 AM, ChangDriver <capav8r(at)gmail.com> wrote:



 	  Quote: 	
		   

 

 Thanks for the reply.  I have two brand new 12 v batteries in series to make the 24 v system.  The current is RPM dependent.  At idle there is no current.  As RPM increases, the current rises.  Like at 1200 rpm 4 amps, 1500, 12 amps, 2000, 22 amps, at t/o power of 2400 rpm 35 amps.

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=407808#407808

ChangDriver

Joined: 15 Sep 2007
Posts: 266

Posted: Sun Sep 01, 2013 5:18 am Post subject: Re: Alternator Putting out MAX Current

The entire system checked out fine per the B&C troubleshooting guide.  Ran the engine at 1200 rpm for 15 minutes and noted the amps drop from 12 to 9.  Deduced the new batteries were not fully charged batteries.  Ran engine to t/o rpm and saw 24 amps.  Went flying and now amps are down to normal 8 amps after an hour and a half flight.



All good!!

mark.bitterlich(at)navy.m
Guest

Posted: Sun Sep 01, 2013 2:42 pm Post subject: Alternator Putting out MAX Current

Looks like closing the door after the horse has left, but here is a word to the wise. 



NEVER put un-charged batteries into your airplane and then fly it.  



NEVER use some kind of "jumper cables" to start your airplane if the battery is dead.  



CHARGE the battteries first with an external charger, and THEN start the motor.  



Ignoring the above  is a good way to fry an alternator or regulator.  



There are a few folks on the YAK list that will be glad to verify the truth of the above.     



Just sayin folks.  Be careful.  



Mark

________________________________________

From: owner-yak-list-server(at)matronics.com [owner-yak-list-server(at)matronics.com] on behalf of ChangDriver [capav8r(at)gmail.com]

Sent: Sunday, September 01, 2013 9:18 AM

To: yak-list(at)matronics.com

Subject: Re: Alternator Putting out MAX Current






The entire system checked out fine per the B&C troubleshooting guide.  Ran the engine at 1200 rpm for 15 minutes and noted the amps drop from 12 to 9.  Deduced the new batteries were not fully charged batteries.  Ran engine to t/o rpm and saw 24 amps.  Went flying and now amps are down to normal 8 amps after an hour and a half flight.



All good!!





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=407843#407843

McFly

Joined: 21 May 2012
Posts: 101
Location: Scottsdale, AZ

Posted: Sun Sep 01, 2013 3:05 pm Post subject: Alternator Putting out MAX Current

I am confused by the squawk.



Are you saying that system voltage is varying with RPM or alternator output is varying with RPM?



If system voltage is varying then it would seem its a bad voltage regulator.



Todd McCutchan

T-34A - N134FA

KDVT Hangar 42-06

Cell (260) 402-1740

E-mail todd(at)fastaircraft.com

www.fastaircraft.com



On Sep 1, 2013, at 3:39 PM, "Bitterlich, Mark G CIV NAVAIR, WD" <mark.bitterlich(at)navy.mil> wrote:



 	  Quote: 	
		   

 

 Looks like closing the door after the horse has left, but here is a word to the wise. 

 

 NEVER put un-charged batteries into your airplane and then fly it.  

 

 NEVER use some kind of "jumper cables" to start your airplane if the battery is dead.  

 

 CHARGE the battteries first with an external charger, and THEN start the motor.  

 

 Ignoring the above  is a good way to fry an alternator or regulator.  

 

 There are a few folks on the YAK list that will be glad to verify the truth of the above.     

 

 Just sayin folks.  Be careful.  

 

 Mark

 

 

 ________________________________________

 From: owner-yak-list-server(at)matronics.com [owner-yak-list-server(at)matronics.com] on behalf of ChangDriver [capav8r(at)gmail.com]

 Sent: Sunday, September 01, 2013 9:18 AM

 To: yak-list(at)matronics.com

 Subject: Re: Alternator Putting out MAX Current

 

 

 

 The entire system checked out fine per the B&C troubleshooting guide.  Ran the engine at 1200 rpm for 15 minutes and noted the amps drop from 12 to 9.  Deduced the new batteries were not fully charged batteries.  Ran engine to t/o rpm and saw 24 amps.  Went flying and now amps are down to normal 8 amps after an hour and a half flight.

 

 All good!!

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=407843#407843

_________________
Todd McCutchan
Fast Aircraft
T-34A - N134FA
KDVT Hangar 33-13

Cell - 260.402.1740

Email: todd@fastaircraft.com
Skype: tmccutchan
Web: www.fastaircraft.com & www.flyams.com

ChangDriver

Joined: 15 Sep 2007
Posts: 266

Posted: Mon Sep 02, 2013 4:57 am Post subject: Re: Alternator Putting out MAX Current

Mark:



Thanks for the last advice.  I got thrown off by the batteries being new and the terminal voltages being 12.1 on each battery and the system showing 24.2 volts.  If we had electric starters in out planes we would notice this immediately as the current demand on the batteries would exceed what they could do if depleted.  The regulator was doing its job the entire time by holding bus voltage at 28.8 (the B&C set point for a 24 v regulator).



 I did not have a charger so I opted to allow the alternator to do the job.  When I saw 35 amps out at t/o rpm, I had visions of heat in the B lead and heat in the alternator.  So, the option of running at a lower amperage for a period of time to charge the batteries was my only option.  Thus allowing the alternator to put out less than rated power for the test/charging flight.



A battery minder might not be a bad idea it I don't fly often.

mark.bitterlich(at)navy.m
Guest

Posted: Mon Sep 02, 2013 3:21 pm Post subject: Alternator Putting out MAX Current

Roger that.  I am sure someone around has a 12 volt charger, so just FYI what you could have done was to charge one 12 volt battery at a time.  There is a lot to talk about here,  a few things more to consider. 



1. I am assuming you are using GEL CELL batteries.  If that is true, typically these batteries have a maximum charge current listed on their specifications.  Those will be exceeded when throwing them into the airplane and going flying.  Hard to say what can happen here specifically, but plate warping, gassing, are in the list of things that might happen.  All resulting in reduced battery life.  



2.  A lot of small aircraft alternators are not really designed for continuous current at maximum ratings.  I.E. an SK-35 alternator and regulator could get pretty darn hot running that kind of output over the long term.  Failure of alternator and/or regular HAS happened to some owners.  Realize you're dealing with about 1000 watts of energy here.  Lots of heat in a kilowatt.  



3.  Some 12 volt chargers have selectable charging currents... those are the ones you want to use for your batteries.  They will sometimes actually allow you to select the type of battery you are charging.  If there is no other choice, turn off EVERYTHING you can to reduce current draw while the batteries are charging like this.  And cross your fingers.    



4.  You might want to check the maximum charging voltage for your batteries, and possibly crank the B&C output down to match that recommendation.  Not the end of the world if you do not, but a charging voltage over the maximum listed will reduce the lifetime of the batteries by causing them to gas. 



Bear, are you reading this?  If so, tell the world your story!    



Yes indeedy.  The Battery Minder: 



http://www.batterystuff.com/battery-chargers/24-volt/aircraft/BM24041AA-S2.html



Works like gangbusters!  It will extend the life of your battery .... and has to be the best darn battery charger I have ever purchased in my life.  Not really a battery "charger" per se, actually just like it says, a "maintainer".  Not cheap... but an extremely wise purchase and worth every cent.  Realize I very rarely endorse a specific product.  This is an exception. 



Mark



________________________________________

From: owner-yak-list-server(at)matronics.com [owner-yak-list-server(at)matronics.com] on behalf of ChangDriver [capav8r(at)gmail.com]

Sent: Monday, September 02, 2013 8:57 AM

To: yak-list(at)matronics.com

Subject: Re: Alternator Putting out MAX Current






Mark:



Thanks for the last advice.  I got thrown off by the batteries being new and the terminal voltages being 12.1 on each battery and the system showing 24.2 volts.  If we had electric starters in out planes we would notice this immediately as the current demand on the batteries would exceed what they could do if depleted.  The regulator was doing its job the entire time by holding bus voltage at 28.8 (the B&C set point for a 24 v regulator).



 I did not have a charger so I opted to allow the alternator to do the job.  When I saw 35 amps out at t/o rpm, I had visions of heat in the B lead and heat in the alternator.  So, the option of running at a lower amperage for a period of time to charge the batteries was my only option.  Thus allowing the alternator to put out less than rated power for the test/charging flight.



A battery minder might not be a bad idea it I don't fly often.





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=407913#407913

pjsales(at)me.com
Guest

Posted: Mon Sep 02, 2013 3:55 pm Post subject: Alternator Putting out MAX Current

Mark- do you recommend a specific battery for the Yak?



PJ Ashura



Sent from my iPhone



On Sep 2, 2013, at 19:17, "Bitterlich, Mark G CIV NAVAIR, WD" <mark.bitterlich(at)navy.mil> wrote:



 	  Quote: 	
		   

 

 Roger that.  I am sure someone around has a 12 volt charger, so just FYI what you could have done was to charge one 12 volt battery at a time.  There is a lot to talk about here,  a few things more to consider. 

 

 1. I am assuming you are using GEL CELL batteries.  If that is true, typically these batteries have a maximum charge current listed on their specifications.  Those will be exceeded when throwing them into the airplane and going flying.  Hard to say what can happen here specifically, but plate warping, gassing, are in the list of things that might happen.  All resulting in reduced battery life.  

 

 2.  A lot of small aircraft alternators are not really designed for continuous current at maximum ratings.  I.E. an SK-35 alternator and regulator could get pretty darn hot running that kind of output over the long term.  Failure of alternator and/or regular HAS happened to some owners.  Realize you're dealing with about 1000 watts of energy here.  Lots of heat in a kilowatt.  

 

 3.  Some 12 volt chargers have selectable charging currents... those are the ones you want to use for your batteries.  They will sometimes actually allow you to select the type of battery you are charging.  If there is no other choice, turn off EVERYTHING you can to reduce current draw while the batteries are charging like this.  And cross your fingers.    

 

 4.  You might want to check the maximum charging voltage for your batteries, and possibly crank the B&C output down to match that recommendation.  Not the end of the world if you do not, but a charging voltage over the maximum listed will reduce the lifetime of the batteries by causing them to gas. 

 

 Bear, are you reading this?  If so, tell the world your story!    

 

 Yes indeedy.  The Battery Minder: 

 

 http://www.batterystuff.com/battery-chargers/24-volt/aircraft/BM24041AA-S2.html

 

 Works like gangbusters!  It will extend the life of your battery .... and has to be the best darn battery charger I have ever purchased in my life.  Not really a battery "charger" per se, actually just like it says, a "maintainer".  Not cheap... but an extremely wise purchase and worth every cent.  Realize I very rarely endorse a specific product.  This is an exception. 

 

 Mark

 

 ________________________________________

 From: owner-yak-list-server(at)matronics.com [owner-yak-list-server(at)matronics.com] on behalf of ChangDriver [capav8r(at)gmail.com]

 Sent: Monday, September 02, 2013 8:57 AM

 To: yak-list(at)matronics.com

 Subject: Re: Alternator Putting out MAX Current

 

 

 

 Mark:

 

 Thanks for the last advice.  I got thrown off by the batteries being new and the terminal voltages being 12.1 on each battery and the system showing 24.2 volts.  If we had electric starters in out planes we would notice this immediately as the current demand on the batteries would exceed what they could do if depleted.  The regulator was doing its job the entire time by holding bus voltage at 28.8 (the B&C set point for a 24 v regulator).

 

 I did not have a charger so I opted to allow the alternator to do the job.  When I saw 35 amps out at t/o rpm, I had visions of heat in the B lead and heat in the alternator.  So, the option of running at a lower amperage for a period of time to charge the batteries was my only option.  Thus allowing the alternator to put out less than rated power for the test/charging flight.

 

 A battery minder might not be a bad idea it I don't fly often.

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=407913#407913

dabear

Joined: 21 Jan 2011
Posts: 92
Location: Warrenton, VA

Posted: Mon Sep 02, 2013 5:16 pm Post subject: Alternator Putting out MAX Current

Mark,  Which story?  I have so many.



However, I do recommend the gel cell and the approved/recommended charger

"battery Minder"



Bear



--

mark.bitterlich(at)navy.m
Guest

Posted: Tue Sep 03, 2013 8:01 am Post subject: Alternator Putting out MAX Current

The only thing I would recommend would probably be an AGM type battery, although Gell Cell is ok as well.  Typically people use two of the 12 volt 18 Amp Hour jobs.  It really just depends on making a really strong container to replace the original.  



I fly a YAK-50, so weight and balance is something to be concerned with.  The only real danger I have seen is running batteries that are way too small, which end up being over-charged and vented easily.  This can be a sneaky event that results in all kinds of bad things happening to avionics and other things as well.  



My recommendation would be to run a load test on your batteries once a year at least.  If you can't do that, then simply go to your airplane and turn everything on with a good meter hooked to the batteries.  Or, just turn on the Master and then Pitot Heat for less than 10 seconds.  Look at your battery voltage and if it sags below 21 volts or so, it's time to get new ones.  My experience is that it is better to buy cheaper AGM batteries and replace them often, than it is to buy really expensive batteries and try to make them last too long.  



Always replace them in pairs versus one at a time, and never hook a wire in the middle of two series batteries to power something that requires 12 volts.  That is the perfect way to cause an early death to one battery and possible additional avionics damage. 



Mark



p.s.  The design of the stock Russian generator charging system RELIES on good batteries in order to DISCONNECT the generator at low RPM.  This is the kind of "sneaky" problem I was mentioning.  If the batteries are very weak, and the generator output goes below battery voltage there will not be enough reverse current to trip out the DMR-200 reverse current relay, and the generator will stay engaged and your main battery rail will drop WELL below 24 volts.  This kind of voltage sag can be less than good to some types of avionics.  You'll notice this when you bring your engine to idle and you do NOT see the "GEN" light come on.  

--

Display posts from previous:

	Matronics Email Lists Forum Index -> Yak-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum