Swiss fund manager SUSI Partners acquired a 50 percent stake in AMS’ Southern California portfolio of distributed battery storage systems Monday. The package includes more than 90 lithium-ion systems adding up to storage capacity of 63 megawatts and 340 megawatt-hours. AMS will continue to operate the assets. AMS secured contracts with utility Southern California Edison back in 2014 to install batteries at commercial and industrial sites to lower both customer bills and grid demand in constrained areas.