The DC-UPS powers your tools from the car using the motor vehicle electrical system, but switches to external battery power if the vehicle's battery is taken out, stolen, or drops below a predetermined voltage, acting like a battery backup (BBU) and power conditioner. The EC650LCD is sufficiently small to hide https://deannenub.worldblogged.com/40144943/facts-about-cctv-power-supply-backup-revealed