GS Yuasa's 5th Generation
Flooded Lead-Acid Battery Technology
for Stop and Start Vehicles
Satoshi Inagaki, Masaaki Kyo, Susumu Obuchi,
Hidetoshi Wada, Taisuke Takeuchi, Tomohiro Imamura
GS Yuasa International Ltd.
7th Advanced Automotive Battery Conference Europe 2017
Outline
1 History of our EFB technology for Stop and Start
2 Market trend in Japan and failure modes in Stop and Start
3 Concept of 5th generation technology
4 Results of accelerated test and field operational test
5 Conclusion
EFB:Enhanced Flooded lead-acid Battery
Outline
1 History of our EFB technology for Stop and Start
2 Market trend in Japan and failure modes in Stop and Start
3 Concept of 5th generation technology
4 Results of accelerated test and field operational test
5 Conclusion
Objective Technologies
Generation
1st 2nd 3rd 4th 5th
2009~ 2010~ 2011~ 2012~ 2017~
Charge/discharge
performance
Increased number
of plates
DurabilityHigh density
PAM
Charge acceptance
Special additive in
electrolyte
Optimized additives
in NAM with
carbon technology
: Improvement as compared with conventional batteries.
: Additional improvement as compared with .
: The new technology for the 5th generation
History of EFB technology
Outline
1 History of our EFB technology for Stop and Start
2 Market trend in Japan and failure modes in Stop and Start
3 Concept of 5th generation technology
4 Results of accelerated test and field operational test
5 Conclusion
300
320
340
360
380
400
420
440
460
480
500
1990 1995 2000 2005 2010 2015 2020
Ave
rag
e m
on
thly
mil
ea
ge
/
km
Year
Market trend in Japan
Reference)
Japan automobile manufacturers association,
Passenger Car Market Trends in Japan (1995-2015)
Influence on batteries
-Few charging opportunity
-Prolonged non-operational time
under PSoC
Popularization
of Stop and Start
vehicles
Users’ average mileage has been
decreasing, because the main purpose
of car users has been changing from
leisure to daily or even weekly small
business.
Transition of user’s average mileage
Failure modes in the field (1)
Battery : M-42 (4th generation, C20=40Ah)
Cars: 2 of different Japanese car manufacturers’ (shown as A and B)
History: A [2218km/9.8months(226km/month)] , B[2017km/9.3months(217km/month)]
5 Fatal degradation
4
3
2
1
0 No degradation
Short-circuits
Sediment ofdropped active material
Shrinkage of NAM
Sulfation of NAM
Change ofseparator color
Dendrite formation
Softening of PAM
Grid corrosion
Car A
Car B5
4
3
2
1
0
Failure modes in the field (2)
Battery : LN3 (4th generation, C20=70Ah)
Cars: 1 of European car manufacturer’s (shown as C)
History: 30640km/22.2months(1378km/month)
Sulfatuion of NAM should be common also in European market.
Average mileage
in Germany (2013)
:1188km/month
In the literature,
sulfation of NAM under short
mileage in Europe is also shown.S. Schaeck et al., Journal of Power
Sources 196(2011) 2933
Short-circuits
Sediment ofdropped active material
Shrinkage of NAM
Sulfation of NAM
Change ofseparator color
Dendrite formation
Softening of PAM
Grid corrosion
Car C
5
4
3
2
1
0
Description of sulfation
In the Japanese car (short average mileage) In the European car (relatively long average mileage)
SEM images of sulfated NAM
Sulfation : Accumulation of highly crystallized lead sulfates (hard to recharge)
→ Bad fuel efficiency and life performance due to the poor charge acceptance.
Outline
1 History of our EFB technology for Stop and Start
2 Market trend in Japan and failure modes in Stop and Start
3 Concept of 5th generation technology
4 Results of accelerated test and field operational test
5 Conclusion
Theoretical interpretation of sulfation
“Reactable Distance” in charging process
Initial stage
Electrolyte
PbSO4
Pb
Pb2+Pb2+
Final stage
Isolated PbSO4
References)
Y. Arai et al., GS Yuasa Technical Report, 11(1),24(2014)
Y. Arai et al., GS Yuasa Technical Report, 12(2),18(2015)
Y. Arai, 9th International Conference On Lead-Acid Batteries(LABAT’ 2014)
Reactable
Distance
Electrolyte
PbSO4
Pb
Isolated PbSO4 should crystallize and go into sulfation during non-operational time.
To reduce the isolated PbSO4 by enhancing the “Reactable Distance” is important.
New carbon technology for 5th generation
Features of the new carbon
CarbonParticle
Size
Electron
Conductivity
Conventional Small Fair
New Large Good
PbSO4
Conventional carbon particles
(much smaller than PbSO4)
Strategy for improving sulfation
With new carbon, the “Reactable Distance” should be enhanced by its large particle
size and high electron conductivity so that only small isolated PbSO4 will remain.
Pb
PbSO4
Electrolyte
Conventional carbon
Short
Reactable
Distance
Large isolated PbSO4
Pb
Electrolyte
Small isolated PbSO4
New carbon
Long
Reactable
Distance
Conductive endCarbons Carbons
PbSO4
Outline
1 History of our EFB technology for Stop and Start
2 Market trend in Japan and failure modes in Stop and Start
3 Concept of 5th generation technology
4 Results of accelerated test and field operational test
5 Conclusion
Sulfation-accelerated battery test
Battery : M-42 (5th and 4th generation, C20=40Ah)
Test Profile : GS Yuasa original (simulating a short mileage use)
Temperature : 10℃
28A
50s
250A 0.5s
12.85V
80s
Max. 50A
1 cycle
Charge
Discharge
Curr
ent
/ A
14.0V
90s 13.2V
40s
0.1A
2 h
(rest time)
Repeat 2 times
Repeat 10 times
Charge/Discharge
balance in the test:
Almost 100%
Sulfation-accelerated battery test
Results
Sulfation was highly suppressed in the 5th generation battery.
5th
4th8.0
8.5
9.0
9.5
10.0
10.5
11.0
0 200 400 600 800 1000
Voltage a
t th
e e
nd o
f 250A
dis
charg
e / V
Cycles
5th generation
4th generation
x1.4
Field operational test
Battery :M-42 (5th and 4th generation, C20=40Ah)
Cars : 1 of Japanese car manufacturer’s (manufacturer A in the previous page)
History: Same 2200km/10months(220km/month) for each battery
Results
Generation
Before field
driving test
After field
driving test
AC-IR
/ mΩ
OCV
/ V
AC-IR
/ mΩ
OCV
/ V
5 th 5.3 12.73 6.2 12.40
4 th 5.3 12.72 7.2 12.29
The same effect was confirmed in the real field
Water Consumption in over charged test
Battery : M-42 (5th and 4th generation, C20=40Ah)
Test Profile : SAE J240 modified (25A for 1min. 14.8V/25A for 10min.at 75℃)
No bad influence with 5th generation technology
Additional information
Our 4th generation satisfies the W3 level
defined in EN 50342-6.
Temp. Voltage Duration Weight loss
60˚C 14.4V 42days5.6g/Ah
(<8)
Battery :LN3 (4th generation, C20=70Ah)0
500
1000
1500
2000
0 1200 2400 3600 4800 6000
Wate
r consum
ption
/ g
Cycles
5th generation
4th generation
Outline
1 History of our EFB technology for Stop and Start
2 Market trend in Japan and failure modes in Stop and Start
3 Concept of 5th generation technology
4 Results of accelerated test and field operational test
5 Conclusion
Conclusion
GS Yuasa’s 5th generation battery with new carbon technology highly suppressed
the sulfation of NAM in accelerated battery test and field operational test.
Other findings
Sulfation of NAM was the major failure mode in Japanese Stop and Start real
market in which the users’ average mileage has been decreasing.
The new technology has no bad influence on the water consumption.
GS Yuasa’s 5th generation battery is suitable for short-trip users.