Because batteries have a limited lifetime, and must be replaced periodically, such battery backup systems ordinarily have a warning indicator when the batteries must be replaced or have a push button that performs a test on the battery indicating their condition. Unfortunately, because the lights may be located in an inaccessible location such as a ceiling, they often go neglected. Thus battery failure occurs, the warning light is ignored (or the system goes untested), and the emergency lighting system does not produce light when needed.
U.S. Pat. No. 9,338,839 illustrates one example of a lighting system for off-grid power failures. For instance, FIG. 23 illustrates a charging circuit 2320 that receives regulated power from the AC mains and discharges power to a power select/condition 2330. The power select/condition 2330 then provides power to a light source/load 2350. The system 2300 also includes a time of use/power source/charge controller 2340 that is separate from the charging circuit 2320. Further, the time of use/power source/charging controller 2340 does not have a data connection or any way to communicate with or control the regulator (part of 2310). Further, a switch is separate from the power select/condition 2330. What is more, the charging circuit 2320 has inputs and outputs where power is received from the regulator via inputs and power is sent to the power select/condition 2330 via the outputs, but not via the same leads. The charging circuit 2320 is also described as having a single non-variable output—that of the battery voltage (e.g., see MCP73838, which is a battery charger without any buck/boost capability for conversion of battery discharge).
SUMMARY OF THE DISCLOSURE
