battery discharging in flight

[flightlogic]

Jim, that is good news. A process of trouble shooting... following the links and finding a solution. And, it is really fun when it turns out to be simple.
So many times that day you set aside.... isn't even enough.

[Paris12Man]

If my battery is fully charged and I only have the D180 turned on (everything else is off) and at 4000 rpm my voltage is 12.2 and amps is -2, does this point to a bad regulator? I've checked the connections and they are good at the regulator. I disconnected plug at regulator and checked the connector pins for signs of shorting and none found.
Could this be an alternator/generator issue??
Your replays are appreciated.
Thanks

[Jetguy]

Check the voltage off the battery terminals or off you power port and report back.

[Mich48041]

Steve, the regulator could be bad. But test the aircraft wiring before replacing the regulator. Do the tests described HERE. Then use a low wattage 12 volt lamp and connect one lamp wire to the regulator case (not to aircraft ground nor to battery negative). And connect the other lamp wire to regulator terminals B and R and C, (one terminal at a time). The lamp should illuminate brightly. Also measure the voltage across the lamp while it is on. The voltage should equal battery voltage. Again, use the regulator case as a voltage reference, not aircraft ground. If no problem is found with aircraft wiring, then replace the regulator. Loading a circuit with a lamp will make problems show up that might not show up with just a voltmeter alone.
Other possible causes of low voltage could be an open alternator circuit, or a blown main fuse, or a half-bad master switch. If you replace the regulator, use heat-conductive grease between the case and the airframe.
Joe Gores

[Paris12Man]

Reporting back....... Voltage off battery is 13.14.

[Paris12Man]

Thanks Joe. I'll work on your suggestions tomorrow and post what I find.

[Mich48041]

Reporting back....... Voltage off battery is 13.14.

The battery is fully charged. Was it charged while flying or later with a battery charger?
Joe Gores

[Paris12Man]

It was charged after my last flight with battery charger. The reading I had today was with a fully charged battery and a ground run-up to 4000 RPM. Voltage showed 12.2 and amps showed -2 amps at 4000 RPM.

[Paris12Man]

I followed the tests that Joe Gores recommended earlier in this thread on the aircraft's wiring today and everything checked out OK. Everything points to regulator problem.
Thanks Joe for your help.

[Mich48041]

Heat is the enemy of electronics. The heat from the regulator needs to be dissipated both by cooling air and by conduction to the airframe. Use heat conductive grease to help conduct the heat away.