A modular battery rack system consists of a series of bi-polar cells having individualized connections for monitoring, charging, discharging, and electrical illumination of weak or damaged cells. Each bi-polar cell has a first surface and a second surface with the first surface being configured to interlock...http://www.google.ca/patents/US5346786?utm_source=gb-gplus-sharePatent US5346786 - Modular rack mounted battery system
