3. A NiMH HEV battery pack is sized based on the following...

3. A NiMH HEV battery pack is sized based on the following requirements: • 12,000cycles of 70 Wh per year for 8 years. • 8 Ah cell with a rated voltage of 3.2 V. • Index of L = 3. i) What is the BOL battery pack energy storage? ii) What is the total number of cells required? iii) What is the pack voltage if the cells are all in series? iv) If the peak power is 50 kW, what is the P/E ratio of the battery?

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00:01 Hello students, given that nickel nimh hev battery is there, so we need to find out to calculate the beginning of life of the battery pack first.

00:16 So, we also need to find out the number of cells required, packing voltage and the p by e ratio of the battery.

00:27 So, we can use the first is battery pack energy storage.

00:33 Battery pack energy storage bol energy storage is equal to cycles per year times energy per year energy per cycle.

00:47 So, that is equal to 12 ,000 cycles per year times 70 watt hour per cycle.

00:56 So, that will give you 8400 sorry 840 ,000 or 840 kilo watt hour is the total battery pack energy storage per year.

01:16 And the second thing is total number of cells.

01:18 So, number of cells is equal to bol divided by cell capacity.

01:28 Let's call this cell capacity cc times voltage of the cell.

01:35 Okay.

01:36 So, that is 840 kilo watt times 8 ampere hour times 3 .2 voltage.

01:44 So, you get 32 ,812 .5 cells.

01:52 So, the number of cells cannot be fractional.

01:54 So, we need at least 332 ,813 cells minimum.

02:02 Okay.

02:03 Now, the third one is pack voltage with all the cells in series.

02:08 So, pack voltage is equal to number of cells number of cells times cell voltage...

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