Motion Sensor Low Battery Voltage?

[Wingsy]

I just ordered 2 motion sensors. I'd like to use lithium rechargeable batteries, but most Li 9v rechargeable batteries are actually 8.4v fully charged and about 7.1v mid-way discharged. (The 9.6v rechargeable lithiums are way expensive.) A standard 9v alkaline would be considered just about dead at 7v. So my question is, at what voltage does the motion sensor trigger a low battery alert? I want the answer to be "around 6 volts", but I'll settle for reality.

[Teken]

I just ordered 2 motion sensors. I'd like to use lithium rechargeable batteries, but most Li 9v rechargeable batteries are actually 8.4v fully charged and about 7.1v mid-way discharged. (The 9.6v rechargeable lithiums are way expensive.) A standard 9v alkaline would be considered just about dead at 7v. So my question is, at what voltage does the motion sensor trigger a low battery alert? I want the answer to be "around 6 volts", but I'll settle for reality.

Speaking only for myself in my personal environment there are several factors to consider. One is variation in MS specs and what tolerances are at play. The other is the quality of the battery cell being used because some cheaper 9 volt cells start to drop off very quickly after a threshold has been met.

I had a recent MS alert me that it was low and at the time of measurement it was 7.30 VDC. Note, the MS can still operate for a considerable amount of time when the (first low battery) alert is seen.

Obviously, it will depend on the amount of activation's / traffic seen.

I had one MS continue to operate for more than a month when the first low battery signal was sent from the ISY.

NOTE: Newer battery operated devices such as the Open / Close, Hidden Door Sensor, both offer the user to set the heart beat and low battery voltage threshold. I am hoping the next iterations of the MS will offer the same features.

[i9i]

Could you please advise on how to set up the low voltage notification in the ISY? I have not been able to find info on this. I have assumed a low battery state (which I believe is on when voltage is greater than whatever the threshold is and off when not) triggers the notification. I can program the notification for the change in state, but I guess I need to know if I need language to only send the notice once or at some interval. Could you possibly comment on what the impact may be on battery life in cold outdoor climates?


Thanks

[stusviews]

Use an integer variable as a condition and change it in the THEN part. Cold kills batteries, use a lithium battery for best results.