This Four Position Battery Charger from Dolgin Engineering is designed to replenish four Canon LP-E17 battery packs simultaneously. The unit utilizes Dynamic Power Management, which independently regulates power to each pack depending on its current charge levels, thus ensuring that every one is charged efficiently and is ready for use at about the same time. The approximate charging time for a set of four fully depleted batteries is 2.5 hours. Additionally, this charger runs on universal 100-240 VAC power for worldwide use, or 12 VDC power with an optional power cable for on-the-go charging in your vehicle.