2.2 Installation of the Hybrid IP-PBX — KX-TDA100/KX-TDA200Installation Manual 472.2.6 Backup Batteries ConnectionThe backup batteries and Back-up Battery Cable (KX-A228 for PSU-S and PSU-M, or KX-A229 for PSU-L) provide a backup power supply to allow full use of the Hybrid IP-PBX in theevent of a power failure. In case of power failure, the backup batteries automatically maintainthe power to the Hybrid IP-PBX without interruption.1. Turn off the battery switch on the PSU.2. Connect the Back-up Battery Cable with 3 identical VRLA (Valve Regulated Lead Acid)batteries (12 V DC × 3).• Turn on the battery switch on the PSU only after the installation of the Hybrid IP-PBX isfinished and AC power is available.• For each backup battery, battery capacity of 28 Ah or below is recommended (otherwise,the battery charge may not be maintained).• Make sure that the type and capacity of the 3 backup batteries are identical.• The Back-up Battery Cable should not be exposed to direct sunlight. Keep the Back-upBattery Cable and the backup batteries away from heating appliances and fire. Place thebackup batteries in ventilated place.• For details about the backup batteries, refer to the manual intended for the batteries.CAUTION• Be sure to comply with applicable local regulations (e.g., law, guidelines).• Make sure that the polarities of the backup batteries and wiring are correct.• Make sure that you do not short the backup batteries or cables.• There is a danger of explosion if backup batteries are incorrectly replaced. Replaceonly with the same or equivalent type recommended by the battery manufacturer.Dispose of used batteries according to the manufacturer’s instructions.• Use the correct type of Back-up Battery Cable for the type of the PSU.Back-up Battery CableBackup Batteries (12 V DC x 3)Red BlackBattery ConnectorBattery SwitchONOFFFuse