Ed Cesnalis Posted July 8, 2022 Report Share Posted July 8, 2022 With my meter set to miliAmps and the negative battery wire disconnected I plut the leads from the negative battery post to the negative battery wire and it reads 160 mA. How can I go about finding this drain? Quote Link to comment Share on other sites More sharing options...
Anticept Posted July 8, 2022 Report Share Posted July 8, 2022 DC clamp on ammeters are finicky at low current and you could just be picking up extraneous fields. Please do a voltage drop test with a resistor as described. I need to know the resistor value too. Even a pencil tip could be used if you dont have any resistors sitting around. Quote Link to comment Share on other sites More sharing options...
Tom Baker Posted July 8, 2022 Report Share Posted July 8, 2022 Look to what was done to the airplane before this started, and start there. Outside of that trace the wire that comes from the battery side of the starter relay, check to see that the insolation is not worn through. Then follow the wire and see what is connected before it gets to the master switch. If you don't find anything check to make sure the master switch doesn't have any current flowing through it. Quote Link to comment Share on other sites More sharing options...
Roger Lee Posted July 8, 2022 Report Share Posted July 8, 2022 I agree with Tom. You said something was just added. It may just be the way the person connected it and it doesn't fully shut down. Disconnect it all together and see if the drain is still there. Quote Link to comment Share on other sites More sharing options...
Ed Cesnalis Posted July 8, 2022 Author Report Share Posted July 8, 2022 38 minutes ago, Roger Lee said: I agree with Tom. You said something was just added. It may just be the way the person connected it and it doesn't fully shut down. Disconnect it all together and see if the drain is still there. The new component is ADSb out. Echo UAT. I know it works cause I always see ground stations and traffic but I don't know where its located or how to tell that it is off. Quote Link to comment Share on other sites More sharing options...
Tom Baker Posted July 9, 2022 Report Share Posted July 9, 2022 Like I said trace the wire from the battery side of the starter relay to the master switch. I would bet the culprit is someplace in between. It could be something tied to the wrong side of the switch, or something attached to the alternator shunt. Quote Link to comment Share on other sites More sharing options...
Ed Cesnalis Posted July 9, 2022 Author Report Share Posted July 9, 2022 12 minutes ago, Tom Baker said: Like I said trace the wire from the battery side of the starter relay to the master switch. I would bet the culprit is someplace in between. It could be something tied to the wrong side of the switch, or something attached to the alternator shunt. Thanks Tom, That does sound most likely. Quote Link to comment Share on other sites More sharing options...
Eddie Cesnalis Posted August 5, 2022 Report Share Posted August 5, 2022 After finding this 163 milliamp drain at the negative battery terminal we found it traveled the white wire from the battery relay to the master switch. Replacing that wire eliminated that drain now all I have to do is leave it untended for a couple of nights. Quote Link to comment Share on other sites More sharing options...
Eddie Cesnalis Posted August 5, 2022 Report Share Posted August 5, 2022 Okay, can 160 milliAmps drain my battery in 2 days? Not sure if this math is correct but 7ah or 7,000 milliampHour charge x 10% = 700 MilliampHours divided by 163 = 4.3 hours = totally dead in 2 days. I think that's right. More simply 7,000 / 160 = 43.75 hours. Quote Link to comment Share on other sites More sharing options...
Anticept Posted August 5, 2022 Report Share Posted August 5, 2022 Doesn't even have to discharge for 2 days. Lead acid batteries have an internal resistance that goes up as they discharge. Also, just a caution, be careful when connecting a meter like that. Read the meter carefully to see what size fuse is installed (it will say max amps somewhere). Fuses for flukes for example are $$$$. They're 30 bucks a piece and are a weird form factor. Quote Link to comment Share on other sites More sharing options...
Eddie Cesnalis Posted August 8, 2022 Report Share Posted August 8, 2022 It worked. I have a new White Power Supply wire from my battery relay to my master switch. My battery held it's charge over the weekend. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.