will these work with alarm sensors?
These only work with the cameras with these model numbers: VMC3030/VMK3200/VMS3330/3430/3530.
This doesn’t seem like a particularly good price for rechargeable cr123a. They can be used in anything that can take an cr123a at 3.7V. Alarm sensors may expect the lower 3.0V from the non-rechargeable variety… you’d need to look into that.
I’ve had mixed results with these batteries. Roughly half of the ones I’ve used from the last pack I purchased have developed problems with holding a charge, under less than a month of use, and only ever having been used indoors. They run out of juice, I put them in the included charger, the charger light turns red (to indicate charging), and then the charger light goes out completely. The light is supposed to turn from red to green when charging is complete, and it does so with roughly half of the batteries, but the other half not so much. It’s like the charger gives up on charging them.
So if you’re going to get these, I might advise buying about twice as many as you really need. Or, better yet, buy them somewhere that will allow you to return the faulty ones.