I know this is a long shot but I try it anyway, maybe Norm, the creator of the excellent conversion equipment BMS+ still reads these fora. Or perhaps someone else can help us. We are building an experimental Vehicle-to-Grid solution, including both EVSE and the on–board unit. Budget is limited so we are opting for a 2007 Prius conversion. We want to use Norm's BMS+2 with a parallel pack built out of 18650 cells in a 70S7P configutation. We read Norm's suggestion on using the BMS+ in this setup as described on hybridinterfaces BMSnew html Second the more DIY approach of a parallel pack of typically 70 or so Lithium cells allows EV and mixed mode operation to the same (if not better) performance enjoyed by BMS+ and parallel Nimh packs. The OEM pack actually runs cooler than a standard Prius due to the current sharing and EV mode can be continuous at much higher current flows. The main difference is that a contactor is engaged during READY mode so that the OEM pack is no longer charged during house charging, thus avoiding any possibility of overheating it. With the correct number of lithium cells, charging them to near 100% involves a higher voltage than the OEM pack could stand. Once fully charged and connected via the contactor, an initial inrush current of <50A flows for under a minute which does not cause OEM heating and operation continues as 2 parallel packs until both have dropped to typically 210v at which point PHEV operation is discontinued until the pack can be recharged. At all times, full regen is allowed for both OEM and added pack My questions are these: 1) Can I use the Tyco Kilovac EV200 contactor with the BMS+? It has a holding current of 130mA. 2) When the parallel 18650 battery pack is fully charged and the car is in READY mode, the BMS+ engages the contactor (initial inrush current of <50A) doesn't it hurt the OEM battery? My battery pack consists of 18650 cells in 70S7P config. Many thanks for the kind response.