Method And Device For Lead-Acid Batteries Operating Under Critical Applications

Boris Shirov, Project Manager R&D, TASC Ltd. BulgariaProf. Vesselin Naydenov, PhD, IEES, Bulgarian Academy of Sciences

TASC Ltd.Bulgaria, 1000 Sofia, 4 Trapesitza Str., Entr. 4tel: +359 887 083394 fax +359 2 9871295e-mail: office@tasc.bg

Contact

1.Patent pending WO2014032128 2.Patent pending WO20140789153.C.J. O'Connor, Magnetochemistry—advances in theory and

experimentation, Wiley Online Library, 2007, Print ISBN: 9780471093701

References

Pravetslab, the R&D laboratory of TASC Ltd., Bulgaria, developed a method and a series of devices for the application of external physical treatments which optimize the chemical, electrochemical, and crystallization processes occurring in lead-acid battery production or operation. The method is based on the application of Low Energy Modulated Magnetic Field (LEIT) in a specific manner. A special modulated magnetic field is created by a specialized electronically controlled device, which has the capabilities to regulate the characteristics of the applied magnetic field. The modulated field is managed by specialized programs, which influence in a controlled way on processes that occur in lead-acid batteries during production and operation.

LEIT

Abstract

Application of LEIT During Operation of Lead-Acid Cells @ -15⁰ C

Performance of Lead-Acid Batteries @ EN 60896-21 with application of LEIT

• Constant application of LEIT on lead-acid batteries during operation at sub-zero temperature increases charge acceptance, improves cycle life and the power output. As a result from the external treatment sulfation on the negative plates was reduced with approximately 20%.

• Constant application of LEIT on lead-acid batteries during operation at high temperatures ensures better cycle life, increased charge acceptance and higher discharge capacity

Conclusions

On the poster are presented the results of research on the effects of external physical treatment on the electrochemical processes of lead-acid batteries that occur during operation under critical applications. Typical for the critical applications are extremely high or extremely low ambient temperatures. The external physical treatment is based on low energy modulated magnetic field (LEIT). LEIT was applied on test cells in two different scenarios:• Constant application of LEIT during operation @

-15⁰ C. Two groups of factory formed cells made series of cycling at -15⁰ C. These cells were also divided into two groups, the first group of cells cycled with constant application of LEIT and the control cycled without application of LEIT. After the cycling the cells were examined with XRD and chemical analysis. Prior to cycling at -15⁰ C all cells performed 5 C10 cycles at 25⁰ C for equalization. The nominal capacity of all tested cells is 30 Ah.

• Constant application of LEIT during operation @ + 40⁰C. Two groups of factory produced UPS batteries with nominal capacity of 7,2 Ah and 38 Ah performed high-temperature deep-cycling test for stationary batteries EN 60896-21.

Figure 1. LEIT applied during operation of a lead-acid test battery.

Capa

city

, Ah

Control Cell

LEIT Cell

Time hhh:mm:ss

Figure 2. C10 cycling @ -15⁰ C

0,8

1

1,2

1,4

1,6

1,8

2

2,2

0 20 40 60 80 100 120 140 160

Volta

ge, V

Time, s

CCA: -18oC; I = 95A

307

1,55 V

LEIT Cell

Control Cell

Figure 3. Cold cranking @ -18⁰ C after 20 cycles C10 @ -15⁰ C

Figure 4. XRD Diagrams of the active masses

Cell %Pb % PbSO4 %PbO

Control 70.38 25.43 2.36

LEIT 93.14 1.99 3.42

Table 1. Chemical analysis

Time for completing 10 C10 cycles:• LEIT Cell – 172:35 h• Control Cell – 388:53 h

Total charged and discharged capacity for the time of 10 C10 cycles of the LEIT cell (172:35 h):• LEIT Cell – 266,68 Ah• Control Cell – 153, 86 Ah

Figure 5. Performance of UPS batteries with and without application of LEIT @ +40⁰ C

• Discharged capacity at the 50th cycle for the 38Ah UPS batteries are:• Battery with constant application of LEIT: 32,42 Ah• Control battery: 20,16 Ah