Hello,

I have done a comparison of the big car batteries and I am not an physics expert (if I was I wouldn’t probably ask questions here) but based on my calculations, connecting a bunch of AA batteries would end up being cheaper and lighter than connecting the large betteries. Here is my comparison:

[B]Car battery:[/B]

Amper-hour: 40Ah

Voltage: 12V

Energy: 12V*40Ah = 48Wh

mass: 1.6kg

Energy/mass: 30Wh/kg

price: $80

To store 12kWh:

batterries needed: 12000Wh/48Wh = 250

price: $80 * 250 = [B]$20000[/B]

mass: 1.6kg * 250 = [B]400kg[/B]

Therefore, to store 12kWh we need to pay $20,000 and our vehicle will weigh 400kg more.

Now, if we used a bunch of AA NiMH betteries:

[B]AA battery:[/B]

Amper-hour: 2.5Ah

Voltage: 1.2V

Energy: 1.2V*2.5Ah = 3Wh

mass: 31g = 0.031kg

Energy/mass: 3Wh/0.031kg = 97Wh/kg

price: $1

To store 12kWh:

batterries needed: 12000Wh / 3Wh = 4000

price: $1 * 4000 = [B]$4000[/B]

mass: 0.031kg * 4000 = [B]124kg[/B]

Therefore, based on my calculations (tell me if I’m wrong), by connecting 4000 AA batteries together, we would be able to store 12kWh of energy by just paying $4000 and our vehicle will weigh only 124kg more.

Please let me know why AA batteries are not being used (whether I have some error in my calculations or there is some other reason for this)

Thank you