XB5XPDR External Battery Pack, DIN-Rail mounting Standard configuration The BVS24XDPDR & BVS48XDPDR DIN-Rail Power Modules must both be equipped with at least one XB5XPDR to function as a full-fledged DIN-Rail 24V DC Uninterruptible Power Supply. Extend runtime By connecting two, three or max four XB5XPDR external battery packs to the associated BVS DIN-Rail Power Module instead of one, you can easily increase the number of minutes that the DIN-Rail emergency power supply can independently supply backup power. A runtime of 3 minutes at 48 watt load is even possible.