Battery Management for Monitoring up to Battery Management for Monitoring up to
Six Lead
Six Lead--Acid Batteries at the Individual Acid Batteries at the Individual
Dr. David Liu, PhD Dr. David Liu, PhD PHM Society PHM Society BMS Workshop BMS Workshop Six Lead
Six Lead--Acid Batteries at the Individual Acid Batteries at the Individual Battery and System Levels
Overview Overview
• Why Do We Need a Battery Fuel Gauge?
• Capabilities and Benefits of HDM BFG Technology • BFG Application Examples
• BFG Configurations • BFG Configurations
• HDM’s BFG Dual Tracking Methodology
• BFG Highlights Effects of Unhealthy Batteries on the Bank
Information is Power Information is Power
You would not drive a car without a gas gauge…
Why would you execute a mission-critical operation, such as “silent watch”,
Capabilities of HDM BFG Technology Capabilities of HDM BFG Technology
• Battery Power Usage Information: Diagnostics and Prognostics
– State of Charge (SOC) at 95% Accuracy
– State of Health (SOH) at 95% Accuracy
– Hours Remaining (HR) at 90% Accuracy
– Battery Voltage (V) – Battery Voltage (V) – Battery Temperature (T) – Current (I)
– State of Life (SOL)
• Functionality
– System Interface: CANBUS, RS232, Control Panel-Mounted Display – Real-Time Data and Estimations
Benefits of HDM BFG Technology Benefits of HDM BFG Technology
• Operations
– Alerts crew when re-charging is necessary – Provides Hours Remaining for silent watch – Ensures mission capacity and success
• Maintenance
– Identifies unhealthy batteries for replacement – Facilitates Condition-Based Maintenance (CBM)
• Cost-Efficiency
– Single BFG per system vs. multiple BFGs per system
BFG Implementation BFG Implementation Mobile Application Mobile Application • Customer – Navistar Defense • UK MOD/NATO • Vehicle
– Husky Tactical Support Vehicle – Husky Tactical Support Vehicle
• Application
– Monitors Battery SOC and SOH
Over 1500 HDM BFGs have been installed in Husky
BFG Implementation BFG Implementation Stationary Application Stationary Application • Customer – Raytheon Company • System
– R-Series Regenerator Hybrid Power System
Power System
• Application
– USMC Experimental
Forward Operating Base Phase IV Demonstration in 2010 at 29 Palms, CA
HDM BFG is critical component of intelligent Hybrid Power
Battery Fuel Gauge Configurations Battery Fuel Gauge Configurations
Configuration 1 Configuration 1
System Level Monitoring Only System Level Monitoring Only
12VDC Battery #3 12VDC Battery #1 D C C h a (A lte 12VDC Battery #5 Interface Connection Inline Fuse
Battery Positive Sense Wire
Advantage: SIMPLICITY 12VDC Battery #4 12VDC Battery #2 L o a d a rg e r e rn a to r) 12VDC Battery #6 Batt Neg Load Neg Interface Connection (Display, RS232, CAN-Bus)
Fuel Gauge Sensor Module
Battery Negative Connection Load Negative Connection
Configuration 2 Configuration 2
Cell Level Monitoring Only Cell Level Monitoring Only
12VDC Battery #3 12VDC Battery #1 Batt Neg Load Neg Batt Neg Load Neg D C C h a (A lte 12VDC Battery #5 Batt Neg Load Neg Inline Fuse
Battery Positive Sense Wire
D A T A R E A D IN G S S O H C e ll S O C C e ll V (V o lta g e ) C e ll Advantage: PRECISION 12VDC Battery #4 12VDC Battery #2 Batt Neg Load Neg Batt Neg Load Neg L o a d a rg e r e rn a to r) 12VDC Battery #6 Batt Neg Load Neg Interface Connection (Display, RS232, CAN-Bus)
Fuel Gauge Sensor Module
Battery Negative Connection Load Negative Connection
V (V o lta g e ) C e ll
H R (H r R e m a in ) C e ll
I (C u rre n t) C e ll
Configuration 3 Configuration 3
System/String/Cell Level Monitoring System/String/Cell Level Monitoring
12VDC Battery #3 12VDC Battery #1 D C C h (A lt 12VDC Battery #5 Inline Fuse
Battery Positive Sense Wire
DATA READINGS SOH SOC Cell/String/System V Cell/String/System Cell/System
Advantage: SIMPLE, PRECISE & COST-EFFECTIVE
12VDC Battery #4 12VDC Battery #2 C L o a d h a rg e r te rn a to r) 12VDC Battery #6 Batt Neg Load Neg Interface Connection (Display, RS232, CAN-Bus)
Fuel Gauge Sensor Module
Battery Negative Connection Load Negative Connection
V (Voltage) HR (Hr Remain) I (Current) Temp Cell/System System Cell/String/System System
HDM’s Battery Fuel Gauge Technology: HDM’s Battery Fuel Gauge Technology:
SOC Measurement SOC Measurement
Using Dual Tracking Method Using Dual Tracking Method
60 80 100 S O C ( % )
Fuel Gauge SOC Theoretical SOC Fuel Gauge SOH:82% (at discharging time = 0 min.)
0 20 40 0 10 20 30 40 50 60 70 80 90 100 S O C ( % )
What is Dual Tracking Methodology? What is Dual Tracking Methodology?
Template for
Template for InitialInitial
II--SOC and VocSOC and Voc--SOC EstimationSOC Estimation
Segments Voc AH SOC (%)
1 > 12.8 2 100-98 2 12.80-12.74 2 98-96 3 12.74-12.69 2 96-94 4 12.69-12.66 2 94-92 . . . . . . . . . . . . . . . . 48 11.14-11.08 2 6-4 49 11.08-10.88 2 4-2 50 10.88-10.64 2 2-0
Template for
Template for SelfSelf--Calibrated Calibrated II--SOC and VocSOC and Voc--SOC EstimationSOC Estimation
Segments Voc AH SOC (%)
1 > 12.8 1.8 100-98 2 12.80-12.74 1.8 98-96 3 12.74-12.69 2.1 96-93 4 12.69-12.66 2.1 93-90 . . . . . . . . . . . . . . . . 48 11.14-11.08 1.6 6-4 49 11.08-10.88 1.6 4-2 50 10.88-10.64 1.8 2-0 Total Segments: 1-50 Voc: >12.8 – 10.64 Self-Calibrated Total AH: 90 SOC: 100%-0%
Error from Current
Error from Current--Based TrackingBased Tracking
60 80 100 S O C ( % ) Charge/Discharge Cycling
Fuel Gauge SOC Overestimated Accurate Underestimated
Lack of precise charge and discharge efficiency information results
0 20 40 0 50 100 150 200 250 300 350 400 450 500 S O C ( % )
Error from Voltage
Error from Voltage--Based TrackingBased Tracking
24 25 26 27 V o c ( V o lt a g e ) V o c ( V o lt s ) B (78%SOC) A (100%SOC) 21 22 23 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 time(mins) V o c ( V o lt a g e )
Voc 12Hrs Rest after Full Charge
Voc No Rest after Full Charge
Time (min) V o c ( V o lt s )
Dual Tracking Methodology Dual Tracking Methodology
60 80 100 S O C ( % ) Combined SOC Voltage-based SOC (% )
Voltage-Based Tracking SOC
0 20 40 0 50 100 150 200 250 S O C ( % )
Discharging Time (min) Discharging Time (min)
S
O
C
Configuration 3 Configuration 3
System/String/Cell Level Monitoring System/String/Cell Level Monitoring
12VDC Battery #3 12VDC Battery #1 D C L C h a r (A lte rn 12VDC Battery #5 Interface Connection Inline Fuse
Battery Positive Sense Wire
DATA READINGS SOH SOC Cell/String/System V (Voltage) Cell/String/System Cell/System
Advantage: SIMPLE, PRECISE & COST-EFFECTIVE
12VDC Battery #4 12VDC Battery #2 L o a d rg e r n a to r) 12VDC Battery #6 Batt Neg Load Neg Interface Connection (Display, RS232, CAN-Bus)
Fuel Gauge Sensor Module
Battery Negative Connection Load Negative Connection
V (Voltage) HR (Hr Remain) I (Current) Temp Cell/System System Cell/String/System System
BFG Detection of Unhealthy Battery: Cycle 1 BFG Detection of Unhealthy Battery: Cycle 1
0 10 20 30 40 50 60 70 80 90 100 0 5 10 15 20 25 30 35 S O C ( % ) Battery 1
Battery Monitor SOC Theoretical SOC Theoretical + 5% Theoretical - 5% 0 10 20 30 40 50 60 70 80 90 100 0 5 10 15 20 25 30 35 S O C (% ) Battery 3
Battery Monitor SOC Theoretical SOC Theoretical + 5% Theoretical - 5% 0 10 20 30 40 50 60 70 80 90 100 0 5 10 15 20 25 30 35 S O C ( % ) Battery 2
Battery Monitor SOC Theoretical SOC Theoretical + 5% Theoretical - 5% 60 70 80 90 100 S O C ( % )
Battery Monitor SOC Theoretical SOC Theoretical + 5% Theoretical - 5% 50 60 70 80 90 100 S O C ( % )
Battery Monitor SOC Theoretical SOC Theoretical + 5% Theoretical - 5% 50 60 70 80 90 100 S O C ( % )
Battery Monitor SOC Theoretical SOC Theoretical + 5% Theoretical - 5%
HDM BFG identifies weak battery during
0 10 20 30 40 50 0 5 10 15 20 25 30 35 S O C ( % ) AH Discharged Battery 4 Theoretical - 5% 0 10 20 30 40 50 0 5 10 15 20 25 30 35 S O C ( % ) AH Discharged Battery 6 10 20 30 40 50 60 70 80 90 100 S O C ( % ) Battery System 6 Batteries Combined
Battery Monitor SOC Theoretical SOC Theoretical + 5% Theoretical - 5% 0 10 20 30 40 50 0 5 10 15 20 25 30 35 S O C ( % ) AH Discharged Battery 5 Theoretical - 5% Battery5
BFG Accuracy Established: Cycle 3 BFG Accuracy Established: Cycle 3
0 10 20 30 40 50 60 70 80 90 100 0 5 10 15 20 25 30 35 S O C ( % ) Battery 1
Battery Monitor SOC Theoretical SOC Theoretical + 5% Theoretical - 5% 0 10 20 30 40 50 60 70 80 90 100 0 5 10 15 20 25 30 35 S O C ( % ) Battery 2
Battery Monitor SOC Theoretical SOC Theoretical + 5% Theoretical - 5% 70 80 90 100 Battery Monitor Theoretical SOC Theoretical + 5% 70 80 90 100
Battery Monitor SOC Theoretical SOC Theoretical + 5% 70 80 90 100 S O C ( % )
Battery Monitor SOC Theoretical SOC Theoretical + 5% 0 10 20 30 40 50 60 70 80 90 100 0 5 10 15 20 25 30 35 40 S O C ( % ) Battery 3
Battery Monitor SOC Theoretical SOC Theoretical + 5% Theoretical - 5% HDM BFG achieves 95% accuracy by discharge cycle 3 30 40 50 60 70 80 90 100 S O C ( % ) Battery System
Battery Monitor SOC Theoretical SOC Theoretical + 5% Theoretical - 5% 0 10 20 30 40 50 60 70 0 5 10 15 20 25 30 35 S O C ( % ) AH Discharged Battery 4 Theoretical + 5% Theoretical - 5% 0 10 20 30 40 50 60 70 0 5 10 15 20 25 30 35 40 S O C ( % ) AH Discharged Battery 6 Theoretical + 5% Theoretical - 5% 0 10 20 30 40 50 60 70 0 5 10 15 20 25 30 35 S O C ( % ) AH Discharged Battery 5 Theoretical + 5% Theoretical - 5%
Effects of Unhealthy Battery on Bank 1* Effects of Unhealthy Battery on Bank 1*
String # Battery # Individual Battery Voltage @ End Point Discharge Current From To SOC % SOH % 1 1 11.3V 12A 19A 10 73 2 11.5V 16 78 2 3 11.4V 10A 18A 12 71 4 11.4V 12 73 5 10.8V 0 50
* Battery Bank 1: Optima Batteries
• String 3: Divergence of voltage and reduction in discharge current
cause over-current stress on Strings 1 and 2
3 5 10.8V 18A 4A 0 50 6 12.0V 36 78 Sum 1 - 3 Sum 1 - 6
System Battery End Voltage: 22.8V
System Discharge Current:
Effects of Unhealthy Battery on Bank 2* Effects of Unhealthy Battery on Bank 2*
String # Battery # Individual Battery Voltage @ End Point
Discharge Current From To SOC % SOH % 1 1 11.3V 33A 49A 14 77 2 11.4V 19 80 2 3 10.6V 33A 6A 0 55 4 12.1V 51 93 5 11.2V 12 75
* Battery Bank 2: Hawker Batteries
• String 2: Divergence of voltage and reduction in discharge current
cause over-current stress on Strings 1 and 3
3 5 11.2V 34A 45A 12 75 6 11.5V 22 87 Sum 1 - 3 Sum 1 - 6
System Battery End Voltage: 22.7V
System Discharge Current:
Weakest Battery Threshold Weakest Battery Threshold
vs. Conventional Threshold at 21V vs. Conventional Threshold at 21V String # Battery #
Battery Voltage Discharge Current Charge Current @ End Point 1
(Bat 3 SOC=0%)
@ End Point 2 (Bat Voltage=21V) @ 100% SOC @ End Point 1 @ End Point 2 @ Low SOC 1 1 11.3V 9.9V
36A 51A 20A 20A
2 11.4V 11.1V
3 10.6V 9.6V
By extending the system run-time (e.g. by 30 minutes), would be at
2 3 10.6V 9.6V 30A 6A 65A 3A 4 12.1V 11.5V 3 5 11.2V 9.7V
36A 45A 17A 19A
6 11.5V 11.3V
Sum 1 - 3
Sum 1 - 6
60 70 80 90 100 S O C ( % )
Battery System Battery Monitor SOC Theoretical SOC Theoretical + 5% Theoretical - 5%
System-Level Monitoring During Complete Charge-Discharge Cycles 0 10 20 30 40 50 0 200 400 600 800 1000 1200 1400 1600 1800 2000 S O C ( % ) AH Discharged/Charged
Single BFG at 95% Accuracy Single BFG at 95% Accuracy for up to 6 Individual Batteries for up to 6 Individual Batteries
• Provides breadth and depth necessary for Cost-Effective Battery Management Systems and CBM
• User Level
– Ensures power system reliability and performance – Ensures power system reliability and performance
• Maintenance Level
– Enables precision pinpoint of unhealthy batteries for CBM
• Incorporates theoretically scalable algorithm, for banks
greater than 6 batteries (i.e. important for larger, stationary energy storage systems)
Thank You!
Contact Information:Dr. David Liu, VP of R&D: davidliu@hdm-sys.com
Dr. David Liu, VP of R&D: davidliu@hdm-sys.com
HDM Systems, Inc. 226 Lincoln Street Allston, MA 02134 Tel: 617.562.4054 Fax: 617.562.4013 Web: www.HDM-Sys.com
Appendix Appendix Appendix Appendix
20 40 60 80 100 S O C ( % )
Initial Discharge Cycle (100% to 50% SOC) (2x55AH 12V Batteries, 24V in Series, 10A/40A Alternating Loads)
Fuel Gauge SOC Theoretical SOC Fuel Gauge SOH: 95% at Discharge Time = 0 20 40 60 80 100 S O C ( % )
2nd Discharge Cycle (100% to 50% SOC) (2x55AH 12V Batteries, 24V in Series, 10A/40A Alternating Loads)
Fuel Gauge SOC Theoretical SOC Fuel Gauge SOH: 89%
at Discharge Time = 0 min.
SOC Measured by Dual
SOC Measured by Dual--Tracking Method:Tracking Method: Partial Discharge
Partial Discharge –– Cycle 1 to Cycle 4Cycle 1 to Cycle 4
0
0 20 40 60 80 100
Discharging Time (min)
0
0 20 40 60 80 100
Discharging Time (min)
20 40 60 80 100 S O C ( % )
3rd Discharge Cycle (100% to 50% SOC) (2x55AH 12V Batteries, 24V in Series, 10A/40A Alternating Loads)
Fuel Gauge SOC Theoretical SOC
Fuel Gauge SOH: 86% at Discharge Time = 0 20 40 60 80 100 S O C ( % )
4th Discharge Cycle (100% to 0% SOC) (2x55AH 12V Batteries, 24V in Series, 5A/40A Alternating Loads)
Fuel Gauge SOC Theoretical SOC
Fuel Gauge SOH: 83% at Discharge Time = 0
50 60 70 80 90 100 S O C ( % ) Battery H2 50 60 70 80 90 100 S O C ( % ) Battery System
Partial Charge and Discharge Cycles Partial Charge and Discharge Cycles
of Battery Bank of Battery Bank
SOC accuracy reaches 90-95% after four partial charge and
0 10 20 30 40 50 0 50 100 150 200 S O C ( % ) AH Discharged/Charged 0 10 20 30 40 50 0 100 200 300 400 500 600 S O C ( % ) AH Discharged/Charged
BFG: Water Submersion Test
BFG was submersed in water at 25°C for three hours, and was tested for operational performance