This article explains how to change batteries on a kwikset deadbolt lock. This applies to the following locks:
Deadbolts: Kwikset Homeconnect 620, Kwikset 888, Kwikset 916
You will need 4 AA batteries.
1) Slide the black plastic cover on the interior of the lock upwards to expose the battery pack.
2) Pull out battery pack from top of the lock electronics
3) Replace batteries - please make sure polarity is correct
4) Re-insert the case into the top of the lock with the arrow pointing towards door
5) Slide black cover back in place. You should hear the lock "beep" if successful.
It make take up to a few hours for the system to eliminate the low battery alert. If you are replacing batteries frequently, please check if there is corrosion on the battery case and sand it down to remove the corrosion if you can. If you notice that your lock is frequently hitting the door frame when you lock the door, please inform your property manager so they can adjust the lock to make sure it goes into the door frame smoothly. This will maximize battery life.
This video shows you how to perform this operation: https://youtu.be/tW5qh08i36c
If you have a Kwikset lever lock (912) please refer to this article for how to change the batteries: