Lecture 4 - A bit about batteries

[@VikashVerma-kn7vi]

The way of explaining the concept of electric vehicle is quite good. Thank you so much sir.

[@shreyash8813]

perfect way of teaching. everyone should get a teacher like you. I thank the platform also where I get to learn under these great professors.

[@Ykotb08]

It is clear you are enthusiastic about the topic and you explain clearly, thank you I really like this course.

[@TPF_Vadodara]

Excellent way of explaining the concept

[@rajeevdeshpande9255]

very systematic & step by step explainatin of the concept.Thanks

[@NITINKumare]

Excellently explaining abt battery technology for the India's EV program

[@sudiptapatra2991]

We can use regenerative braking

[@h7opolo]

Answer to HW 1.3 @ 24:25: 1) since the battery is rated for 2 kWh and the depth of discharge (DoD) is only 85%, then the entire discharge will be 1700 Wh which matches the recharge of 1700 Wh. But you only pay for electricity when you charge the battery, so 1.7 kWh multiplied by the electricity rate gives the Rupees cost per full charge, which is repeated 1825 times, giving a total charge cost of 1825 days x 5 Rupees/kWh x 1.7 kWh = 15,512.50 Rupees for five years' worth of battery power. 2) the range of the car is dependent on the battery power capacity multiplied by the DoD, divided by the car's mileage. this yields a range of 1.7 kWh per day divided by 20 Wh/km = 85 km/day. 3) since 85 km is driven every day, the total distance driven is number of days multiplied by the distance per day = 1825 days x 85 km/day = 155,125 km. 4) the total battery cost is equal to the original cost plus the Interest and depreciation payment per year multiplied by the number of years considered. 1825 days divided by 365 days/year yields exactly 5 years. Therefore, we compute the PMT according to the provided formula at 24:25, and multiply the result by five. A = (0.12/year x 5 years x 30,000 Rupees)/1.55 = 18,000 Rupees is the total extra cost of Interest and depreciation over five years. Then we add A to the original battery cost to get the total cost of the battery: 18,000 Rupees + 30,000 Rupees = 48,000 Rupees. 5) Now we have all the factors we need to compute the final answer in units of cost per kilometer by adding up the total battery cost to the total electricity cost and then dividing that by the total number of kilometers driven. This yields: (48,000 Rupees + 15,512.50 Rupees)/155,125 km = *0.409 Rupees per kilometer.*

[@h7opolo]

in step 4) the PMT is multiplied by 5 because the PMT is a per year rate and the length of the term is five years. Thus, the PMT formula is misleading since you can effectively omit the "divided by 'no of unit time'" step.

[@nikunjgujarathi8610]

In pt 4. There is a calculation error. A comes out to be 11612 and not 18000. You have not divided the calculation by 1.55

[@gagandangwal7011]

Please upload assignment solutions 🙏

[@Muzeemkhankamaal]

Detailed explanation. Thanks.

[@m3nalrimawi629]

How can I get the slides of lecture ?

[@indian4307]

Great teaching 👍 👏 👌

[@kunaldeshattiwar7261]

0.06 per kilometre cost for fuel 18000 Rs of electricity it takes as per domestic electricty rate Rs 5 per unit Battery run 270000 life time 150 km at a single charge according to depth of discharge Near about 1600 w/h we used always Does it right sir?

[@theunsoundfeelings9650]

i think 85 km can be driven with single charge and discharge

[@sofyb.varghese5953]

@@theunsoundfeelings9650 I am getting 85km as well

[@harish7176]

@@sofyb.varghese5953 how to calculate this ?

[@h7opolo]

@@harish71761) since the battery is rated for 2 kWh and the depth of discharge (DoD) is only 85%, then the entire discharge will be 1700 Wh which matches the recharge of 1700 Wh. But you only pay for electricity when you charge the battery, so 1.7 kWh multiplied by the electricity rate gives the Rupees cost per full charge, which is repeated 1825 times, giving a total charge cost of 1825 days x 5 Rupees/kWh x 1.7 kWh = 15,512.50 Rupees for five years' worth of battery power. 2) the range of the car is dependent on the battery power capacity multiplied by the DoD, divided by the car's mileage. this yields a range of 1.7 kWh per day divided by 20 Wh/km = 85 km/day. 3) since 85 km is driven every day, the total distance driven is number of days multiplied by the distance per day = 1825 days x 85 km/day = 155,125 km. 4) the total battery cost is equal to the original cost plus the Interest and depreciation payment per year multiplied by the number of years considered. 1825 days divided by 365 days/year yields exactly 5 years. Therefore, we compute the PMT according to the provided formula at 24:25, and multiply the result by five. A = (0.12/year x 5 years x 30,000 Rupees)/1.55 = 18,000 Rupees is the total extra cost of Interest and depreciation over five years. Then we add A to the original battery cost to get the total cost of the battery: 18,000 Rupees + 30,000 Rupees = 48,000 Rupees. 5) Now we have all the factors we need to compute the final answer in units of cost per kilometer by adding up the total battery cost to the total electricity cost and then dividing that by the total number of kilometers driven. This yields: (48,000 Rupees + 15,512.50 Rupees)/155,125 km = *0.409 Rupees per kilometer.*

[@h7opolo]

for starters, you forgot that the PMT is "per year", thus the PMT needs to be multiplied by five, instead of "divided by 'no of unit time'" as shown in the video. @kunaldeshattiwar7261

[@Saurabhkumar-gx2wu]

so as the battery is discharged once every day, then cost of charging it every day is 5*2=10... am i right?

[@Saurabhkumar-gx2wu]

sir, it's all blank after PMT, what do we need to do further

[@bundesligaofficial8690]

Watching this from Bangladesh

[@NITINKumare]

Depth of discharge DOD

[@pranavbelgaonkar8634]

Does this course have a textbook ?

[@ANILKUMAR-nw3su]

there is no specific book for such courses. materials are taken from multiple books and professors knowledge.

[@n.p.9997]

I got 1.1829 Rs/km. Is it correct?

[@h7opolo]

check my other response for mathematical steps. i got .409 Rupees/km.

[@rangarajaniyerswaminathan7025]

So guys we have 2kWhr battery of which only 85% will be used so its 1.7 kWhr available .Daily its charged and unit rate is Rs5 so daily it will cost Rs8.5 and it will be give 85km/Day so in all lifetime total energy cost is 8.5*1825=15512.5 RS and in all it can go 87*1825=15512.5km.Do correct me guys .

[@vijaysarthy6759]

could u pl tell me how did u get this 87. thanks.

[@vijaysarthy6759]

also how did u arrive at 85 km per day. we dont know the energy efficiency,. pl help me clear this...thanks

[@h7opolo]

check my other reply for the mathematical steps. @@vijaysarthy6759

[@manjunathsankolli]

Good teaching

[@NITINKumare]

SoH state of health

[@NITINKumare]

Slow charge, fast charge 1 hr or less

[@girijakumarpuranik4097]

Anyone solved the problem asked at the end of lecture ?

[@girijakumarpuranik4097]

Over the lifetime of battery , the fuel cost is coming only half rupee per km !!!!

[@saketbishnoi]

@@girijakumarpuranik4097 yes i solve it in my case the fuel cost/km is 0.39125 rs /km

[@saketbishnoi]

the answer range is somewhere between .36 and .37

[@akhilspai]

Is the pmt equation correct?

[@gagandangwal7011]

It's coming out around .268

[@NITINKumare]

EOL End of life

[@AdityaChoumal]

[@megaprimegamer1184]

Just goes to show EVs are not viable at all in India until 2030 at the least

[@Saurabhkumar-gx2wu]

just shut up dumbo... we are at it

[@Alive6371]

NPTEL lectures are so boring !

[@akki_the_kid_but_26]

Really? I don't think so.

[@srijeethj3616]

nope

[@akki_the_kid_but_26]

@@srijeethj3616 at least not prof Ashok sir's lecture

[@surajs5913]

No matter how good the lecture is, if you are not really interested or immersed in the problems, you will find the lectures boring

[@Alive6371]

@@surajs5913 I find it boring *period* If you don't, then move on !