Hawkeye Innovations 12V Battery Watchdog
EV conversions have critical devices that must always have 12V power. These include a BMS, the vehicle entertainment system memory, and other devices. All of these present a parasitic draw on the 12V system's battery that oftentimes, drains it so low that the EV will not power-on. This is a problem not only with conversions, but with some factory EVs as well.
The 12V Battery Watchdog is the simple solution to this problem. It continuously monitors the voltage of the 12V system's battery, and when a specified low point is reached, it will command the DC/DC converter to charge the battery back up to a safe level, then following a selectable runtime (4 minutes by default), it will power-down the converter. The Watchdog's circuitry includes an internal relay with normally closed (NC), normally open (NO), and common contacts (C) to be used as a low current 12V trigger source to operate a larger High Voltage (HV) external relay or contactor to power on-off your EV's DC/DC converter. The status LED will illuminate when active.
The Watchdog works seamlessly when used with the Elcon DC/DC converter we offer. Special note: All SCMs already have the Watchdog built-in. For proper operation, it is important that your DC/DC Converter has a soft start feature, like our Elcon 1 kW converter. If using another brand of DC/DC converter that may not have a soft-start feature, you will have to add a pre-charge feature to it. This product works best with at least a 1 kW rated DC/DC converter that will quickly bring up the 12V battery in a matter of minutes. If your converter's output power is less, you may want to consider specifying a longer 'charge' duration in the box below.
Internal relay is rated for 0.5A at 12VDC, and should be used for signal level only. It will trigger at a programmable low voltage threshold specified by the user, and will stay engaged for a programmable specified duration.