In one embodiment, CDU 901 mainly includes heat exchanger 911, liquid pump 912, and a pump controller (not shown), and some other components such as a liquid reservoir, a power supply, monitoring sensors and so on. Heat exchanger 911 may be a liquid-to-liquid heat exchanger. Heat exchanger 911 includes a first loop with inlet and outlet ports having a first pair of liquid connectors coupled to external liquid supply/return lines 931-932 to form a primary loop. The connectors coupled to the external liquid supply/return lines 931-932 may be disposed or mounted on backend 905 of electronic rack 900. The liquid supply/return lines 931-932 are coupled to a set of room manifolds, which are coupled to an external heat removal system, or extremal cooling loop. In addition, heat exchanger 911 further includes a second loop with two ports having a second pair of liquid connectors coupled to liquid manifold 925 to form a secondary loop, which may include a supply manifold to supply cooling liquid to server blades 903 and a return manifold to return warmer liquid back to CDU 901. Note that CDUs 901 can be any kind of CDUs commercially available or customized ones. Thus, the details of CDUs 901 will not be described herein.

In some embodiments, the data center can utilize a common cooling system to provide cooling to the IT equipment, as well as to cool the TEC of the batteries. For example, a common AC system can blow cold air to the IT room as well as the battery room. A common chiller can chill fluid that is pumped to the IT rack as well as to cooling channels that cool the TEC of the batteries.