Method and apparatus for monitoring battery back-up power in an alarm system

1. An alarm system comprising:

a system controller;

at least one of an alarm and a detector interconnected with the system controller;

at least two batteries interconnected with the system controller, the alarm system selecting a battery from the at least two batteries and operating from the selected battery, each of the at least two batteries having a capacity to individually back up the alarm system for a standby period;

a battery charger powered from a power source and interconnected with the system controller; and

a switching network coupled to the battery charger and to the at least two batteries, the switching network being capable of transferring one battery to charge and the other battery to discharge, the battery being discharged providing power to the alarm system, and the battery charger used to charge the battery that is not providing power to the alarm system.

2. The alarm system of claim 1 further including a voltage converter connected to the at least two batteries, with the at least two batteries comprising 12V batteries, the voltage converter being configured to derive 24V from one of the 12V batteries to power the alarm system.

3. The alarm system of claim 1 further wherein the alarm system monitors the at least two batteries.

4. The alarm system of claim 3 further wherein the alarm system monitors recharging of the battery being recharged.

5. The alarm system of claim 4 further wherein the alarm system monitors efficiency of the battery being recharged in converting electrical energy to stored energy as a measure of battery health.

6. The alarm system of claim 3 further wherein the alarm system monitors discharging of the battery providing power to the alarm system.

7. The alarm system of claim 6 further wherein the alarm system monitors the discharging of the battery providing power to the alarm system to determine if the battery being discharged has sufficient capacity to power the alarm system.

8. The alarm system of claim 3 further wherein the alarm system monitors battery voltage and current over time to determine battery capacity.

9. The alarm system of claim 3 further wherein a signal is provided when one of the at least two batteries is unhealthy.

10. A method of providing power to an alarm system comprising:

providing at least two batteries that are interconnected with a system controller within the alarm system;

selecting a battery from the at least two batteries and operating the alarm system from the selected battery;

when the battery operating the alarm system reaches a discharge level, switching the batteries so that a previously charged battery from the at least two batteries is now operating the alarm system; and recharging the previous battery operating the alarm system.

11. The method of providing power to an alarm system of claim 10 wherein the at least two batteries include a first 12V battery and a second 12V battery.

12. The method of providing power to an alarm system of claim 10 further including monitoring the at least two batteries.

13. The method of providing power to an alarm system of claim 12 further including monitoring recharging of the battery being recharged.

14. The method of providing power to an alarm system of claim 13 further including monitoring efficiency of the battery being recharged in converting electrical energy to stored energy as a measure of battery health.

15. The method of providing power to an alarm system of claim 10 further including monitoring a discharging rate of the battery operating the alarm system.

16. The method of providing power to an alarm system of claim 10 further including monitoring -discharging of the battery operating the alarm system to determine if the battery operating the alarm system has sufficient capacity to power the alarm system.

17. The method of providing power to an alarm system of claim 12 further including monitoring battery voltage and current over time to determine battery capacity.

18. The method of providing power to an alarm system of claim 12 further including signaling when one of the at least two batteries is unhealthy.

19. A method of monitoring power in an alarm system comprising:

providing a battery to operate the alarm system, the alarm system comprising at least a system controller and at least one of an alarm and a detector, the battery and the at least one of an alarm and a detector interconnected with the system controller;

alternatively charging and discharging the battery, the discharge of the battery being used to power the alarm system; and

monitoring the charging and discharging of the battery.

20. The method of monitoring power in an alarm system of claim 19 further including providing a first battery and a second battery and switching between the first and second batteries such that, when the first battery is discharging and powering the alarm system, the second battery is charging and vice versa.

21. The method of monitoring power in an alarm system of claim 19 further including monitoring charging of the battery being recharged.

22. The method of monitoring power in an alarm system of claim 21 further including monitoring an efficiency of the battery in converting electrical energy to stored energy as a measure of battery health.

23. The method of monitoring power in an alarm system of claim 19 further including monitoring discharging of the battery providing power to the alarm system.

24. The method of monitoring power in an alarm system of claim 23 further including monitoring the discharging of the battery providing power to the alarm system to determine if the battery has sufficient capacity to power the alarm system.

25. The method of monitoring power in an alarm system of claim 19 further including monitoring battery voltage and current over time to determine battery capacity.

26. The method of monitoring power in an alarm system of claim 19 further including signaling when the battery is unhealthy.