turtlebot charging without battery

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Unfortunately my turtlebot was delivered without the additional battery: 4S2P (4400 mAh) that has to be connected in the bottom of the kobuki base. Is there any way to charge the turtlebot 2 with Kobuki base without this battery. I tried to charge the turtlebot with the adapter which plugs in next to the on/off switch, but this doesn't work. I also tried to charge it via the docking station, but also without success.