Z-Wave lock depletes batteries

[danshtr]

Hi All,

My Z-Wave door lock is using 4 AA batteries. They sometimes hold for weeks and sometimes they don't hold even for 48 hours.

When the batteries deplete in a short period of time, I notice that only two out of 4 batteries are depleted, the other two are measuring 1.55V.

Any idea how come batteries that are in series can deplete at a different rate?

-Dan

[Armadillo]

You didn't say if the batteries are all from the same NEW batch, so could be 2 old and 2 new.   

[danshtr]

All new batch. Tried two different vendors: Amazon and Energizer (bought from Energizer store at Amazon).

[edavid]

Any idea how come batteries that are in series can deplete at a different rate?

There is probably an additional connection to the center tap of the battery string.

[Armadillo]

The best is to confirm it with a multimeter set to ohms [if not auto then set to high ohm range].
With the batteries out, black probe to known negative terminal and red probe to positions as shown.
Only the known Positive and Negative should indicate a ohms reading.
otherwise you may have a hidden circuit or a conductive leak from previous battery leaks, for example.

[danshtr]

I have tested on all points, all showed out of range

EDIT - forgot to add: the voltage on the "9V battery clips" is 6.3V

[danshtr]

I might have inserted the battery holder upside down.

I can not confirm or deny that the batteries had contact with the PBC directly... 

[Armadillo]

I forgotten to add;

Your AA battery compartment must be hook/connected to the Z-Wave Lock for the measurement to be Correct, Otherwise you will be measuring empty space.

But luckily, there is no conductive leak.

Connect the empty holder into the circuit and measurement again to confirm.

[Armadillo]

OK at least you have found the problem and solution.