Busbar supports and methods of their use for battery systems

A battery system comprising:

• a plurality of battery subunits, each subunit comprising a heatsink and at least one battery cell with a positive terminal and a negative terminal;
• a plurality of busbar supports equal in number to the plurality of battery subunits and each of which is mounted on the heatsink of a corresponding different one of the plurality of subunits, each busbar support including a first slot through which the positive terminal of the at least one battery cell for that subunit passes and a second slot though which the negative terminal for the at least one battery cell for that subunit passes, said plurality of busbar supports including a first busbar support;
• a first busbar located above and held at least in part by the first busbar support and electrically connected to the negative terminal passing through the first slot in the first busbar support;
• and
• a second busbar located above and held at least in part by the first busbar support and electrically connected to the positive terminal passing through the second slot in the first busbar support.