Kwikset Short Battery Life

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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Just went through the same thing with the kwickset 888 called customer service and they sent out a brand new one and it seems to work fine with the old lock i was changing batteries every 2 days

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I have a 913 that was eating batteries even though I was using the best quality fresh dates energizer batteries available. I’m not connected to anything wirelessly and Still the batteries last about two weeks. This lock is well mounted and turns easily with no resistance. The lock is in my pool house so it maybe gets used twice a day. I want to say they have a very professional phone support and they have been kind enough to send me not one but two replacements but the result is the same. I tried using the key for a week the last time and it still ran down without the motor being used. Bottom line is there is a serious battery drain issue in the 913. I’m going to have to seek another brand,

Do yourself a favor and get rid of that lock! I swapped mine out for the schlage equivalent door handle zwave lock and have not had a problem since. I also heeded the previous advice in this thread and kicked the lithium batteries.

I too, just experienced the same with the 888 model. It was draining my batteries, brand new every 2-3 days!!!

I contacted their support number, created a case, did some over the phone troubleshooting and determined it is a faulty motor. They’re going to review and checking stock inventory and promised to ship one out to Me.

Thank you for your input, it helped Me out big time.

The good news is that a Kwikset Smart Lock will tell you when the battery is low several weeks before it runs out. A red light indicates that the device’s battery is low.

Keep in mind that your key will still work if the lock dies before you can replace the Kwikset Smart Lock battery.

Kwikset battery short life is a problem with the ABnB guests, especially long-stays of over a month.

Four batteries @ 1.5vdc = 6vdc.

Has anyone just used a small modular power supply in the wall that wires power through the door to the Kwikset. Seems like a piece of cake to do.

It’s something I’m about to tackle. Wired door hinges are sold off the shelf in various colors, probably for home security systems.

Hey John! Any update on this? I was thinking the same thing but I wanted to use my landscaping wiring to power it. Any insight would be great!

I don’t know if it’s an option for you but I highly recommend the schlage version of this lock type. I switched mine after my kwikset drained out a new set of batteries and have never looked back. The amount of time you will spend wiring this lock through the doorframe will likely end up costing you more in time than just buying a lock that works well. Jist my two cents. The schlage locks have been rock solid. I will never buy another zwave lock type.