Zwave Locks Modify Battery to Wired Power

Other Devices & Integrations Door Locks & Sensors
#1

Has anyone found a power supply for any of the Zwave Lock Levers (Kwikset, Yale, Schlage) that uses the 4 AA Battery Setup.
I desperately need a power supply that someone has found that works.
Thanks a million.

I.e. Like the Yale YRL220ZW619
Schlage FE599NX CAM 619 ACC 619 Home Keypad Lever with Z-WavE
Kwikset Model: 912TNL TRL ZW 15 SMT

#2

Are you asking if there is a slide in unit that replaces the battery holder that has a power supply wired to it, or just a power supply that will work? If just a power supply, you just need a 6V DC power supply. I think the most an AA battery can put out is 2.4 amps, but I can’t imagine you would need anything close to that for a door lock. A typical AA battery has just over 2 amps storage. Kwikset says at 10-15 accesses a day, a pack should last a year, and that’s good down to 4.3 volts, so the amp draw would have to be very low.

#3

I’m curious how you would implement this if you can find a power source that would work. How would you solve for the fact that the lock itself is on the door and moves. If the locking system and electronics were in the door jam rather that the door itself I can see how powering it wired may be possible but how will you do it on the door itself…? In from the hinged side of the door and a wire stapled across the center of the door…?

#4

I’m thinking that if you come onto the door at the hinges with a coil wire like a phone line so it won’t fatigue from flex, it would work. You could run to every door from one power supply on low voltage line.

You could also do spring loaded contacts in the door jamb. Wait, scrap that, you need constant contact.

#5

I am thinking of mounting all of my new door locks in the door jam to make use of power supplies and hardwire them to the homes power so I do not have to change batteries ever again.
I have a prototype designed for this in my outside vinyl gate and it seems very feasible.

1 Like
#6

Hi DaveJet,
Did you ever get an answer for that problem. I would love to have it if you did. I need to power supply for a few schlage locks with something like that. I would like to keep the batteries as backup but use a DC 6Volt supply when there is no short of electricity.

#7

Just connect a 6v DC supply to the terminals in the lock. Do it right and you can slide the batteries right in as well.

You might want to check them every so often to make sure they’re not leaking but long life Alkalines should be good for years.

C

#8

What you say will work, but it is not a good idea to connect a supply direct to batteries, as any fault with batteries may cause the current to flow through the batteries cooking them. It would be best to fit a 6 volt relay to connect batteries upon power supply failure.

1 Like
#9

Completely agree. Much more elegant!

C

#10

Hi, I disagree. Putting a 6volt DC supply to the terminal locks along with the batteries would put them in parallel and at one point in time the DC Power supply would leak into the battery and I can guess what would be next.
As for putting a relay, it looks good and I tried it already. The DC was powering the relay and if they were a loss of power the relay would fall open for the batteries. I thought it was good. But keeping the relay close all the time weirs it down and it eventually breaks and the batteries are being used.

Then I thought about using 2 transistors instead (one PNP and the other NPN). Since my knowledge of electronics is only slight, I was hoping for an easy solution and buy something that already exists.

#11

Have you tried a solid state relay?

#12

Hi,

All you need is a couple of diodes. One for the battery pack and one for the supply.

2 Likes
#13

Thanks for answering.
I did not. To tell the truth, I did not know what it was until you mentioned it. I’m not saying you’re wrong, I just don’t know how. Because the way I see how it works, It flops when it receives an electrical signal. If the main DC stop, it cannot send a signal that it’s not working. Only the battery would be left to send something. I need some sort of comparison process. Because of the lack of knowledge, I can’t seem to put my finger on it.

#14

I did that too. I put the two supplies in parallel and used a diode “Schottky” to make sure that the DC was not leaking into the batteries. It actually worked. But eventually, the battery was depleted. It lasted longer, I think so, than usual. I’m sure it’s obvious. And if you have a sketch for that circuit, one that works, it would be one easy solution that I would love. It just did not work properly the way I implemented it.

#15

You would need a NC solid state relay.

https://uk.farnell.com/c/switches-relays/relays/solid-state-relays-contactors/solid-state-relays?contact-configuration=spst-nc
https://uk.farnell.com/crydom/do061a-b/ssr-1a-60vdc/dp/1613862

The diodes would stop feed back but not battery drain.

#16

Hi,

For the batteries to drain when using diodes, the voltage coming from the power adapter has to be lower or equal to the voltage coming from the batteries. You need to ensure that the 6v adapter can provide all the current/power required by the lock. Failing to so, will cause the adapter voltage to drop and allowing the batteries to contribute in powering the lock. I would not go below 2A for the adapter.

image

Update I initially proposed the use of 2 diodes in the battery path however after consideration, I don’t think it’s the way to go since the voltage drop would be too important.

In the proposed configuration, the batteries might, when brand new, contribute to power the lock a little but as soon as their voltage start to drop below the adapter voltage, they will just be blocked and remain at that level for a very long time. The voltage of the power adapter is the key here.