The OctoStat is an 8-channel instrument that is ideal for battery testing, either as a stand alone instrument or as part of a stacked high-channel count system as shown below. This multichannel potentiostat is also perfect for other electrochemical research that requires multiple channels for simultaneous measurement. It is available in a few versions depending on your current requirements, and is also compatible with a booster that can increase the current on each channel to 16A (channels are combinable).
A high-channel count version of a testing stack is shown below, which includes several modules for temperature and differential voltage measurements (e.g. half-cell measurements).
Full details of the OctoStat can be found here, or by following the quick link on the right hand side of the page.