Battery Management Systems for Large Lithium Battery Packs

With the boom in hybrid-electric automobiles and advances in solar and other battery intensive technologies, new systems for the management of lithium-ion batteries are in demand. Andrea, an experienced battery systems expert, presents this guide for engineers designing, deploying or maintaining lithium-ion battery management systems (BMS). Outlining battery types and functions, BMS design, procurement, production and deployment, this volume includes step-by-step technical information as well as circuit diagrams and illustrations. Access to additional and updated information, online tools and a discussion forum is included. Annotation ©2010 Book News, Inc., Portland, OR (booknews.com)

A battery management system (BMS) is any electronic device that manages a rechargeable battery pack. The BMS monitors the battery pack's state, calculates secondary data, offers protection, and controls its environment. This timely book provides a solid understanding of battery management systems (BMS) in large Li-Ion battery packs, describing the important technical challenges in this field and exploring the most effective solutions. Professionals find in-depth discussions on BMS topologies, functions, and complexities, helping them determine which permutation is right for their application. Packed with numerous graphics, tables, and images, the book explains the 'whys' and 'hows' of Li-Ion BMS design, installation, configuration and troubleshooting. This hands-on resource includes an unbiased description and comparison of all the off-the-shelf Li-Ion BMSs available today. Moreover, it explains how using the correct one for a given application can help to get a Li-Ion pack up and running in little time at low cost.

Preface		xi
Chapter 1 Introduction		1	(34)
1.1 Naming Conventions		1	(1)
1.1.1 Cells, Batteries, and Packs		1	(1)
1.1.2 Resistance		1	(1)
1.2 Li-Ion Cells		1	(14)
1.2.1 Formats		2	(1)
1.2.2 Chemistry		3	(1)
1.2.3 Safety		4	(2)
1.2.4 Safe Operating Area		6	(1)
1.2.5 Efficiency		6	(3)
1.2.6 Aging		9	(1)
1.2.7 Modeling		10	(2)
1.2.8 Unequal Voltages in Series Strings		12	(3)
1.3 Li-Ion BMSs		15	(3)
1.3.1 BMS Definition		16	(1)
1.3.2 Li-Ion BMS Functions		16	(1)
1.3.3 Custom Versus Off-the-Shelf		16	(2)
1.4 Li-Ion Batteries		18	(15)
1.4.1 SOC, DOD, and Capacity		18	(4)
1.4.2 Balance and Balancing		22	(9)
1.4.3 SOH		31	(2)
References		33	(2)
Chapter 2 BMS Options		35	(16)
2.1 Functionality		35	(6)
2.1.1 CCCV Chargers		35	(2)
2.1.2 Regulators		37	(1)
2.1.3 Meters		38	(1)
2.1.4 Monitors		39	(1)
2.1.5 Balancers		40	(1)
2.1.6 Prelectors		41	(1)
2.1.7 Functionality Comparison		41	(1)
2.2 Technology		41	(3)
2.2.1 Simple (Analog)		42	(1)
2.2.2 Sophisticated (Digital)		43	(1)
2.2.3 Technology Comparison		43	(1)
2.3 Topology		44	(7)
2.3.1 Centralized		44	(1)
2.3.2 Modular		45	(1)
2.3.3 Master-Slave		46	(1)
2.3.4 Distributed		47	(2)
2.3.5 Topology Comparison		49	(2)
Chapter 3 BMS Functions		51	(56)
3.1 Measurement		51	(7)
3.1.1 Voltage		52	(2)
3.1.2 Temperature		54	(1)
3.1.3 Current		54	(4)
3.2 Management		58	(30)
3.2.1 Protection		58	(5)
3.2.2 Thermal Management		63	(1)
3.2.3 Balancing		64	(20)
3.2.4 Redistribution		84	(3)
3.2.5 Distributed Charging		87	(1)
3.3 Evaluation		88	(9)
3.3.1 State of Charge and Depth of Discharge		89	(6)
3.3.2 Capacity		95	(1)
3.3.3 Resistance		96	(1)
3.3.4 State of Health (SOH)		97	(1)
3.4 External Communications		97	(8)
3.4.1 Dedicated Analog Wire		98	(1)
3.4.2 Dedicated Digital Wire		99	(3)
3.4.3 Data Link		102	(3)
3.5 Logging and Telemetry		105	(1)
References		105	(2)
Chapter 4 Off-the-Shelf BMSs		107	(14)
4.1 Introduction		107	(14)
4.1.1 Simple		107	(4)
4.1.2 Sophisticated		111	(6)
4.1.3 Cell Manufacturers' BMSs		117	(1)
4.1.4 Comparison		118	(3)
Chapter 5 Custom BMS Design		121	(108)
5.1 Using BMS ASICs		121	(4)
5.1.1 BMS ASIC Selection		121	(3)
5.1.2 BMS ASIC Comparison		124	(1)
5.2 Analog BMS Design		125	(19)
5.2.1 Analog Regulator		125	(2)
5.2.2 Analog Monitor		127	(11)
5.2.3 Analog Balancer		138	(6)
5.2.4 Analog Protector		144	(1)
5.3 Ready-Made, Digital BMS Designs		144	(8)
5.3.1 ATMEL's BMS Processor		144	(1)
5.3.2 Elithion's BMS Chip Set		145	(1)
5.3.3 National Semiconductors' Complete BMS		146	(1)
5.3.4 Peter Perkin's Open Source BMS		147	(2)
5.3.5 Texas Instruments' bq29330/bq20z90		149	(2)
5.3.6 Texas Instruments' bq78PL114/bq76PL102		151	(1)
5.4 Custom Digital BMS Design		152	(67)
5.4.1 Voltage and Temperature Measurement		152	(23)
5.4.2 Current Measurement		175	(3)
5.4.3 Evaluation		178	(14)
5.4.4 Communications		192	(10)
5.4.5 Optimization		202	(13)
5.4.6 Switching		215	(3)
5.4.7 Logging		218	(1)
5.5 Cell Interface		219	(7)
5.5.1 Nondistributed		219	(1)
5.5.2 Distributed		220	(6)
5.6 Distributed Charging		226	(3)
Chapter 6 Deploying a BMS		229	(28)
6.1 Installing		229	(23)
6.1.1 Battery Pack Design		229	(14)
6.1.2 BMS Connections to Pack		243	(4)
6.1.3 BMS Connections to System		247	(5)
6.2 Configuring		252	(1)
6.2.1 Cell Configuration		252	(1)
6.2.2 Pack Configuration		252	(1)
6.2.3 System Configuration		253	(1)
6.3 Testing		253	(2)
6.4 Troubleshooting		255	(1)
6.4.1 Grounding		255	(1)
6.4.2 Shielding		255	(1)
6.4.3 Filtering		255	(1)
6.4.4 Wire Routing		256	(1)
6.4.5 Nuisance Cutouts		256	(1)
6.5 Using		256	(1)
Reference		256	(1)
List of Acronyms and Abbreviations		257	(4)
Glossary		261	(8)
About the Author		269	(2)
Index		271

Davide Andrea is the owner of Elithion LLC. He has more than 25 years of experience in the electronics industry and is a leading expert in the area of BMS development. He holds a B.S. in electrical engineering and computer science from the University of Colorado.