Normally closed magnetic contacts with a short 3/4" switch.
Excellent experience with this vendor
82-4750 - 12V 5.0Ah Rechargable Sealed Lead Acid Battery
ELK Sealed Lead Acid Batteries are excellent for the following applications with regard to size, Amp hour rating, and proper terminal connections: battery backup (for Access Control Systems, Fire Alarm Systems, and Security Alarm Systems), emergency lights, lighte...
I ordered batteries and a set of test leads. I received them within three days of when I ordered them and I got a great price. Fast service and a great price - what more could you want.