Kwikset Short Battery Life

I will check but it Won’t be for a couple of weeks - it’s our vacation home and we came home this morning.

You can check online in the IDE under my devices. See what device handler it’s using.

Sorry for the delay - it is a zwave

Sorry - it is zwave and zigbee system.

Hi all, just had this problem with my 916. Dead batteries at midnight, swapped out (tested them first), then had dead batteries less than 24 hours later. Called Kwickset and they walked me through resetting my system by pressing the circle button for 30 seconds then when it went to a red light take my finger off press the button again take my finger off. It kills all the codes I was told, so had to add a code to test it back.

Basically what that did was discharged the capacitor which can have juice in it showing the system the battery is dead. However when I checked the batteries that I just placed the night before all of them had a charge to him just like what it was previously.

So now I’m testing to see if the new batteries I just placed in tonight are going to last more than the 24 hours. If everything is good, simple fix. If not they will replace my unit. Also it doesn’t disable the Z wave that’s connected to it.

One additional thing, in my ST last night after I changed the batteries I was still seeing 0% battery on the new swapped out ones. Once I did this capacitor flush my ST is now showing 100% battery. Feeling like this could be the fix.

keep us updated! I have had to change out the batteries on this lock weekly for far too long. The amazon basics rechargeable batteries will get me to almost two weeks of battery life though!

Here is the update:

I just changed out the batteries yesterday 3/17/19 when they were down to 20%. I didn’t use my best batteries on this test, so I think this is a solution. I again will have to discharge the capacitor as it’s showing only 20% again, but I put brand new batteries in again. I would say this is a success to reset and get everything working again. Basic Duracell batteries lasted almost 3 months on a heavy use front door.

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The forum is abuzz with questions about Kwikset z-wave module and battery issues:

I’ve seen three separate topics in the past week on the 910 having all types of issues.

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916 zwave here with the same battery drain issue. Hub is about 10 feet from the door. Duracell copper tops last less then a week. However, take the batteries out of the lock and they work just fine in other devices. It almost has to be a reporting issue. I hope this gets fixed quickly, it’s really annoying.

Ok, was just able to prove my point. Went from “battery power to low to operate door”. Pulled battery pack, pressed the button 3 times then held it in while replacing the pack. Door proceeds to do hand check, unlock, relock a few times with smart things app, now reporting batteries at 70%. Something is majorly jacked up with battery reporting.

I wish I found this thread before I decided to switch from Alkaline to the expensive Energizer Lithium everyone is talking about. Is it possible the problem is the batteries here?

Some background on my situation…
I have a Kwikset 912 z-wave lever lock on my garage door to keep guests out and a Schlage deadbolt on the door guests use to get into the house. I got sick of having to change batteries so often so splurged and picked up the Energizer Lithium. They have been amazing in my Schlage deadbolt but apparently completely drained in Kwikset 912 in under 2 weeks. I have had the Kwikset 912 for about a year and never had a full drain issue with the Alkaline batteries.

Unfortunately, I completely neglected to keep the physical key outside of the locked area (I know, won’t make that mistake twice) and had to drill the lock about 30 minutes ago. I ordered a replacement Schlage but would still very much like to salvage the kwikset for some less critical space.

Without sidetracking this thread too much, does anyone know If I can replace the core of the Kwikset 912? I was able to take the drilled piece out but can’t find part numbers or spares anywhere. I called kwikset support and they told me I need to special order the entire external keypad part from Lowe’s or HD. I calling BS on them and am pretty sure the core of this lock is just like any other. Hopefully someone here can confirm and direct me to where I can purchase the replacement part. Photo attached for reference. 1556555890417957468126314271114|249x499

I bought a device to rekey my kwikset locks.

Step1 remove the cylinder.

Seems like you should be able to swap cylinders as long as the donor device looks like the other ne you are going to.

Yeah something weird is going on. Rechargeables last a week alkilines last a few months.

That’s actually expected and explained above.

Rechargeable batteries have a lower operating voltage around 1.3V v/s 1.5V for alkaline batteries. Lock circuits are calibrated to cut off lock operation when the voltage falls below a certain threshold, e.g. 1.1V. The voltage discharge curve of a alkaline battery is longer so it takes longer to get to 1.1V where as rechargeable batteries get to 1.1V much faster hence the lock circuit powers down much faster. For that matter Lithium batteries have a much flatter voltage curve so they take longer to get to 1.1V (but i’ll happen much faster in the end like in a few hours v/s days) so they are able to extract the most juice from batteries before the lock does.

To make things more interesting is the difference between no-load and load voltage drops. When the lock draws a large amount of power from the battery (e.g. when operating the deadbolt), it causes a temporary voltage drop due to internal resistance of the battery. Rechargeable batteries have a higher voltage drop (it varies depending on chemistry, NiCD or NiMH, NiMH are better of the two) under heavy load than alkaline batteries (Lithium have the least), so it very likely that when operating the deadbolt the lock will suddenly “die” when using rechargeable batteries. Infact some locks like Schlage BE469 have a huge current draw and cause this phenomena even with alkaline batteries and so it’s recommended to change deadlock batteries at 60% instead of waiting for it to go lower. This is explained here and you can find some recommendations about it here.

Due to difference in battery chemistry/voltages and the lock chip cut voltages, rechargeable batteries are not recommended to use with locks.

Not that this helps, but my Kwikset 914 has batteries that are at least 4 months old. I am using high quality lithium ion rechargeable batteries. The door lock is used about 8 times a day (via SmartThings) during the week and more on the weekends.

The 914 is about 5 feet away from the SmartThings v2 hub.

Edit - they are NiMH batteries.

Lithium ion batteries are 3.6 to 4.2v, your lock needs 1.5v batteries. You’re probably frying your circuits. You should ONLY use 1.5v batteries like an Alkaline battery or at best a 1.5v Lithium battery and never a Lithium Ion battery.

I was mistaken. The batteries are NiMH

The rechargeable lithium ion batteries are for a quad copter. I should’t post half awake (or is it half asleep)

Depends if the glass is half full or half empty.

You may not get the full use of your batteries, see my post above and the link s in it which explain why, it’s related to the battery voltage of NiMH batteries which are lower than Alkaline and Lithium 1.5v so the circuit shuts down faster, depending on the voltage and load put on your NiMH batteries. When the motor runs it puts a heavy load on the batteries and if the battery can’t supply it the voltage tanks and it shuts off the circuit to the lock.

REF, for a steady state small current draw voltage curve:

Under heavy load the voltage will drop faster for lower quality batteries.

Yes, I read your post about how alkaline batteries are better. Perhaps in this application these batteries work well. The last time I swapped out the rechargeable NiMH batteries was in April 2019. Again, the lock is locked and unlocked from SmartThings 6 times a day and more on the weekends.

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