How To Change the Battery on Your Honeywell 5815 Wireless Contacts

This video will show you how to change the battery on a Honeywell 5815 Wireless Contacts!

First, find the slot on the side of the contact. Insert a small flathead screwdriver into the slot and twist. Inside, you’ll find a 3V lithium battery, CR 123. When you remove the battery, be sure to lift up from the Positive (+) side. When you insert the new battery, insert the Negative (-) side first. 

Finally, place the cover back on. And that’s it! 


Updated on: June 11th, 2026

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