Garage Door Opener - excessive current?

[Excavatoree]

I'm not familiar with this sort of calculation, so I'd appreciate someone letting me know if I'm "in the ballpark" here.

My garage door opener uses a standard 9v battery, and I measured the current (not transmitting) at 13 µA.   

I couldn't find any discharge curves that low, but at 100 ma, the most batteries hit the cliff at about .35 ampere hours.  (.30 - .45)

So, at 13 µA, that's .35/.000013 = approximately 27,000 hours.  That seems like a long time, and that my current draw isn't a problem, but I can't help but believe I've made a mistake.

My other garage door opener's standby current is zero using the same meter, but it's a different brand. I'm not sure if that's relevant.  It does make me think that 13 µA is too high. 

[voltsandjolts]

Yeh, agree with calcs.
13uA is fine for a door opener transmitter when not transmitting.

[PlainName]

My other garage door opener's standby current is zero using the same meter

Some don't connect the battery until you press the button, so standby current should be 0uA.

[Zero999]

It should last for about 3 years whilst not being used, which seems reasonable to me.