Linear Technology, a maker of battery stack monitoring ICs for EVs and hybrids, demonstrated a concept car featuring a wireless battery management system (BMS) at the recent Electronica Show in Munich.
The concept vehicle, developed by design partner LION Smart, combines Linear’s battery stack monitors with its SmartMesh wireless mesh networking products in a BMW i3, replacing the traditional wired connections between the battery packs and the BMS.
Linear believes a fully wireless BMS offers great potential for improved reliability, lower cost and weight, and reduced wiring complexity for large multicell battery stacks.
Linear’s LTC6811 is a complete battery measuring device for hybrid/electric vehicles that can measure up to 12 series-connected battery cell voltages with better than 0.04% accuracy. Combining the LTC6811 with Linear’s SmartMesh wireless mesh networking system addresses the reliability issues associated with automotive wiring harnesses and connectors.
SmartMesh embedded wireless networks are designed to deliver >99.999% reliable connectivity by employing path and frequency diversity. In addition to improving reliability by creating multiple points of redundant connectivity, the wireless network enables additional BMS capability. Wireless connectivity enables more flexible placement of battery modules, and makes possible the installation of sensors in locations that are unsuitable for a wiring harness. Wireless sensors integrated into the SmartMesh network, such as current and temperature monitors, offer the potential for synchronizing these measurements with cell voltages.
“Linear’s innovations in two critical industry leading technologies enables wireless battery management at automotive reliability levels,” said Linear VP Erik Soule. “New designs of electric and hybrid vehicles are increasing rapidly, and all of the major automotive manufacturers are searching for ways to improve the performance and reliability of their battery management systems as they move into higher volume production.”
“Combining Kreisel Electric’s laser-welded 18650 modules with direct liquid cooling and Linear Technology’s SmartMesh IP wireless mesh and the LTC6811 battery monitoring IC, together with LION Smart’s Open BMS, enabled a unique battery system with record-breaking charge time of just 15 minutes, an energy capacity of over 55 kWh, with a range of over 400 km,” said LION Smart CEO Daniel Quinger.
Source: Linear Technology