1979 M20K 231 Turbo Voltage regulator

[Aspen2013]

Purchased new concord battery. Literature that was shipped with battery states the minimum voltage at different temperatures to charge battery correctly.

1. I cannot find the voltage regulator and 

 

2. is it the adjustable type?

 

3. is there a ne solidstate option available?

[carusoam]

Are you sure those directions are related to charging in flight by the plane’s alternator..?

As that doesn’t make sense. Are you going to adjust the voltage based on the OAT you are flying at?

Seems like that would be an instruction to follow for charging before it gets installed in the plane...

Getting a specific charger for your battery while the plane is in the hangar probably has temperature compensation...

Look up BatteryMinder for that....

As for looking for the voltage regulator... Often, they are hiding on the backside of the wire wall.... Early Mooneys had them on the front side of the firewall.  It makes sense to keep it close to the alternator that it controls...

PP thoughts only, not a mechanic...

Best regards,

-a-

[dlmorris]

I own the same year bird. The voltage regulators (I have 2 alternators) are behind the breaker panel on the right side and can be seen from underneath. I have used Concord batteries for years and never touched the regulators. I suggest the same.    

[Aspen2013]

During flight or an RPM of 1500 the voltage that you should see on your system should be close to 14 volts.  Mine usually reads 12.9 - 13.1 volts. Seems a little low. This is supposedly checked and adjusted at an annual inspection.  Not sure that is being done. check out this article.. Mike Busch has an article also.

http://www.concordebattery.com/otherpdf/ac0811_batteriesconcorde_reprint0811_web4c.pdf

 

[Marcopolo]

@Aspen2013,

 

  I also have a 231, 1981 though, but same engine and charging system.  Due to the gear driven alternator, 1500 rpm is a bit low to expect 14.1 volts on our system in my opinion.  Also you would need to be looking at the voltage directly off the alternator to get the actual output voltage, not the battery buss as anything you have turned on will be drawing against that 14.1 figure.  I usually cruise my 231 at 2450 RPM and expect the battery bus to level off at about 13.8v in normal usage scenarios.  Tested on the ground, I was getting 14.1v at 2200rpm at the back of the alternator (or a lead coming directly from the alternator +).  The OEM voltage regulator is adjustable (charge voltage, over voltage threshold, and one other adjustment that I can't recall right now) as is the suggested Zeftronics regulator if you need a replacement.

 

Hope this helps!

 

Ron