SMAKN&reg; Backup Uninterruptible Power Supply UPS AC 110V-240V to DC 13.5V 12 Volt Battery Charger 3A Input voltage: 110V-240V AC, 50/60Hz Output : DC 13.5V, 3A, 36W Dimensions: 110mm x 79mm x 37mm With battery interface, the maximum can be equipped with 12V 20AH battery;With UPS function, control battery charging status automatically. Single output, it can switch to battery power automatically as battery detecting, protecting, power cuting;With protections of short circuit, overcurrent, overvoltage .