Wheelchair BMS Part of an FDA certified medical device Small footprint 59 mm x 59 mm (2.33 x 2.33 ) Provides constant current cell balancing. Designed to work with multiple battery chemistries. Tested on lithium iron phosphate, lithium iron titanate, and lithium manganese batteries. Generate low battery and critical battery signals. Low parasitic current draw (tested with radio between 300 500 ua or 0.3 0.5 ma or 2.7 4.4 amp/hr per year). Multiple temperature sensor inputs in addition to one on the PCB. Multiple and redundant protection circuits.
BMS Cell Monitor / Balance Boards Small footprint 68mm x 60mm (2.7 x 2.4 ). Monitors 2 4 cells. Provides constant current balancing. Designed to work with multiple chemistry batteries. Tested on lithium iron phosphate, lithium iron titanate, and lithium manganese batteries. Radio link (2.4 ghz) to Master BMS Low parasitic current draw (tested 300 500 ua (0.3 0.5 ma) = 2.7 4.4 amp/hr per year). Multiple temperature sensor inputs in addition to one on the PCB. Multiple and redundant protection circuits. Used to prototype wheelchair lithium ion battery solution.
Master BMS With optional touch screen color LCD Display CAN 2.0b Communication USB interface for updating firmware and connecting to terminal Designed to interface with VCU and overlapping VCU functions to facilitate prototyping new systems. Inputs o Key On (12 V) o Charger On (12 V) o *Program 1(Charger / Cooling)(12V) o *Program 2 (12 V) o Inductor Pickup (analog 0 5 V) o 12 Volt Monitor (analog 0 15 V) Output (12 V 300ma) o *Limp Home o *Stop Driving o *Stop Charging Relay Drivers (Drives +12 volt 10 AMP) user needs to fuse properly o *Pre Charge user needs to fuse properly o *Charge user needs to fuse properly o *Programmable 1 (e.g. DCDC) user needs to fuse properly o *Programmable 2 (e.g. cooling system) user needs to fuse properly Special Features o *micro SD Card writer for battery / BMS historical information. o Optional bluetooth module Software Features 1. Initial balance load control. 2. CAN bus charger control. 3. Individual Cell Voltage and Temperature monitoring 4. State of Charge monitoring (SOC) 5. State of Health monitoring (SOH) 6. Hi / Lo voltage Display and Logging 7. Hi / Lo temperature Display and Logging
History 2007 Version 1.0. Set first world record in fall 2007 with Type 65 Coupe with BMS 1.0. Was transferred to 1927 model T in 2009 (also set a world record) and used through 2011. 2009 Version 2.0. Microprocessor controlled BMS installed into 65 Coupe (broke world old record), Shelby 427 roadster continuation, class 8 electric semi truck, 2 electric Porsche conversions, and sold 200 units for outside SSI conversions. Still in use in several vehicles. 2011 Version 3.0. First radio enabled version. Built and tested as part of a low cost 400 amp fast charging station using local battery storage to lower the infrastructure cost, reduce strain to electrical net, and buy electricity at lower rate. 2012 Version 4.0. First ultra low power BMS used as part of a portable, hot swappable, backpack based, power pack prototype for a Qualcomm test engineer mobile network test and optimize suite. 2014 Version 5.4 Ultra low power with radio, constant current shunting, reduced footprint, reduced cost, master BMS to supplement prototypes and end user conversions. Production run Installed into 65 Coupe and 4 other Beta tester vehicles July 2014. 2014 Version WC 5.4J Wheelchair BMS based on version 5.4, added 2 CPU for designed to meet medical grade standards, and custom modifications for existing powered wheelchair switch over from lead acid to lithium batteries. Finished Beta run now shipping. Electric Class 8 semi Built by Vision Motors, SSI, and Cal Motors 1927 model T 65 Coupe at Detroit International Auto Show
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