8 Re-Orientation of Leads Side ViewTop ViewS. Thomas, 2012Re-orientationPlan, drawings? Figures?S. Thomas, 2012Power and BMS Leads to Top of PackConsolidate Wiring Plugs to Single, Central Point.Messy, Prone to Damage
10 Battery Management System Constantly check between cells for over-voltage (3.6V)Manually turn on/off power supplyShunt power resistors1. Take note of any cell sets approaching overvoltage.2. IF greater than 4 cell sets have approached overvoltage in the same 3 minute time period, pack is charged.3. ELSE IF one cell set has approached overvoltage - shutdown charger, use quick-connect and power resistor to bring cell set back to pack voltage at a rate equivalent to that of charging.4. ELSE Maintain charging.S. Thomas, 2012
11 Rejected ideas – BMS On-Board BMS WeightNo need for discharge balancing (Throttle Response)Arduino Control W/ Relay Power ResistorEmulates physical charging sequenceComplicated apparatus, highlikelihood of user error/malfunctionCCCV power supply shutoff problemsShortenedPhoto necessary?Arduino, 2012
12 Battery Management System Final Design: FET CircuitLimits cell voltages to 3.6VDissipates excess current to heat sinkSelectable characteristics
13 Full FET Circuit 8 FET circuits in total Dissipate over- voltage power through back of FET to common heat sink(Al, finned, 10cm x 40cm)CITE STEVE
14 BMS Plan B PreFab Unit Over-Designed, Expensive - Capable of measuring up to 108 cells connected in series based on configuration.- Performs intelligent cell balancing (passive).- Calculates state of charge (SOC).- Uses professional automotive-grade locking connectors.- Calculates discharge current limit (DCL) and charge current limit (CCL).- Can measure cell voltages between 0.5v and 5.0v.Dr swan: is this dumb?Orion BMSCapable of measuring up to 108 cells connected in series based on configuration.Configurations available in increments of 12 cells in series.Centralized design provides high EMI and noise immunity.Performs intelligent cell balancing (passive).Calculates state of charge (SOC).Uses professional automotive-grade locking connectors.Calculates discharge current limit (DCL) and charge current limit (CCL).Can measure cell voltages between 0.5v and 5.0v.Dual (x2) CANBUS 2.0B interfaces (fully programmable).OBD2 diagnostic protocol support.Orion BMS, 2012
33 Recommendations from 2011/2012 team Existing PrototypeRecommendations from 2011/2012 teamBelt on Primary ReductionReduce NoiseWaterproofingProtect Battery leadsSmaller chainCite DanPhoto of last year’s bike, side-on. Point to design recommendations.
34 Sound Testing ResultsFrom Fall 2012 Term Report
35 Battery Energy Storage System 48V System64 Li-Ion CellsNominal 3.3V each, 3.6V full chargeNominal 528 Wh of energy storageBrief!!Energy Storage? Dr. Swan?Two 24V in series
36 FET Characteristics FET Specs: V1 < V2 < 3.6V Capable of dissipating 20A at 3.6V (72W)To be finalized based on VDC
37 Battery Energy Storage System AcrossIncrease wire gage from 16 to (14, 12?) to handle increased current potential.