POWER SUPPLY DEVICE AND SYSTEM

To provide a power supply device and a system, where usability is improved when a plurality of battery packs are mounted.SOLUTION: A power supply device comprises: a power supply box 2 to which a plurality of battery packs BT1 to BT4 can be connected concurrently, each battery pack including a plurality of cell units; a power source cord 4 that extends from the power supply box 2 and is capable of being connected to an external AC power supply; and an adapter 6 that is provided at a tip of a cable 5 extending from the power supply box 2 and is capable of being mounted on an external electric tool 50. Each of the battery packs BT1 to BT4 includes the plurality of cell units and can perform switching connection of the plurality of cell units between serial connection and parallel connection. The power supply box 2 can output DC voltage to the electric tool 50 by connecting in series the plurality of battery packs in each of which the plurality of cell units are connected in parallel.SELECTED DRAWING: Figure 4 【課題】複数の電池パックを装着した場合の使いやすさを向上させた電源装置及びシステムの提供。【解決手段】電源装置は、複数のセルユニットを有する複数の電池パックＢＴ１〜ＢＴ４を同時に接続可能な電源ボックス２と、電源ボックス２から延びて外部交流電源に接続可能な電源コード４と、電源ボックス２から延びるケーブル５の先端に設けられて外部の電動工具５０に装着可能なアダプタ６、とを備える。電池パックＢＴ１〜ＢＴ４は、それぞれ複数のセルユニットを有し、複数のセルユニットを直列接続と並列接続の間で切替え可能である。電源ボックス２は、複数のセルユニットを並列接続した状態で、複数の電池パックを直列接続して直流電圧を電動工具５０に出力可能である。【選択図】図４