Ideal Battery Drain

[ravengolfer]

My GS300 battery keeps dying while the car sits over night. Battery and alternator checks good. I measured 0.9 amp battery drain w/engine off and nothing on. Seems high for Alarm/ECU drain. Does anyone know the spec?

[sakataj]

welcome to the forum! no clue......u running anything aftremarket in the car? tv?alarm? autostart? my autostart on my es used to kill my battery every now and then! 0.9......seems little high

"i will welcome myself back to the forum as im,woo hooooooooo, finally unsuspended! hahaha!"

brian

[SRK]

The alarm and ECM would pull maybe 10-30 milliamps at most. You have .9 A or 900mA, which is a lot.

Hook the ammeter in series with the battery positive, and start pulling fuses to determine what circuit the draw is on. When you hit the right fuse, the draw will disappear. That will narrow things down. Just make sure all other loads are off - interior and trunk lights and so on.

[boB_2006_GS300]

I don't know what year car you have, but I read some posts in the 2006+ GS forum that some people that had a keyless ignition and left the key-fob in the car for a long while had their battery drain too.

[ravengolfer]

The alarm and ECM would pull maybe 10-30 milliamps at most. You have .9 A or 900mA, which is a lot.

Hook the ammeter in series with the battery positive, and start pulling fuses to determine what circuit the draw is on. When you hit the right fuse, the draw will disappear. That will narrow things down. Just make sure all other loads are off - interior and trunk lights and so on.

I did pull the fuses and it was the ECM that was drawing most of the 900mA. The reading was in the microAmps w/o the ECM.

Thanks

[ravengolfer]

welcome to the forum! no clue......u running anything aftremarket in the car? tv?alarm? autostart? my autostart on my es used to kill my battery every now and then! 0.9......seems little high

"i will welcome myself back to the forum as im,woo hooooooooo, finally unsuspended! hahaha!"

brian

The Lexus (wifes car) is fully stock w/no aftermarket toys and no autostart. I save those for my Porsche.

[sakataj]

i dunno brother......u seem to have some draw on the ecm but what all does that power when the cars off? you tried taking it to a stereo shop? could throw a optima in there and hope that covers it..........kinda crappy fix but tracing a electrical draw can be very timely and expensive unless you know someone. thats y im glad my best friends own a stereo shop here in town!

"i will welcome myself back to the forum as im,woo hooooooooo, finally unsuspended! hahaha!"

brian