If you ever want to get confused, just start checking into Electric Car batteries. I know that 98% of our population does not know anything about batteries. In this blog, I am going to try to shed a little more light on the subject, but do not expect this to be a total explanation. I have worked with batteries for a very long time. I have even entertained my grandchildren by making batteries by sticking nails into different fruits and vegetables, like potatoes and oranges. The principle is the same as with the batteries you buy at the store. With all the push for electric cars, we all need to know a lot more about batteries.
Most people do not know that the very first automobiles were powered by batteries and electric motors. It was several years later that the first internal combustion engine car came along. Steam engine cars came before internal combustion engine cars too. You all need to know that. In the end, for all kinds of reason, the internal combustion engine car won out and that is where we are today. Now on too batteries.
Energy stored in a battery is measured in "Watts" and "Time". Things like voltage and amperes figure into the calculation, but in the end it is Watts X Time or watt hours or "wh". On your energy bill they will show it in terms of kwh or kilo wh. This means 1,000 wh and will have a cost of about $0.15. Next, Horsepower is one common way to measure mechanical power, but power is still power, all the same. For ref, one horsepower times one hour is equal to about 3/4 of a kwh. I may use this later. With me so far?
Since electric cars depend on energy stored in the battery, let's shift to how we can compare batteries. I blogged while back about the Tesla electric car and their claim to be the leader on the basis that they had a battery that could store a kwh of energy in their battery costing $500. They claimed that this was much better than all the other car companies and thus they were more likely of ending up with the "best" electric car. You know me and that I pride myself in my grasp of 4th grade math. Let's look deeper into this $500 one kwh battery and to do that, let's compare on the basis of the cost on just "one" wh. The Tesla has a cost of just $0.50 per wh.
Next, I checked out Sam's Club to see what their 6volt golf cart battery would cost per wh. They had a deep cycle 6 volt golf cart battery that had a cost of $84.52 that could put out 20 amps for one hour. I do not know if it was their objective to confuse or not, but to make any kind of comparison this has to be converted to wh. Using 4th grade math, it works out to 120 wh. Next we do long division and come up with $0.70 per wh. This is clearly more than the Tesla battery, but Sam's price was retail and Tesla's was "cost". If Tesla expects to make a profit, I would expect their retail price to be about the same. The point is that with all the hoop-la, the fancy Tesla battery is not any more economical than the one from Sam's Club, but there is more.
Just to keep this interesting, I checked with Harbor Freight to see what the numbers showed on their cordless drill battery. It has a retail price of $10.40. The spec's show that it can store 23.4 wh. Again, the 4th grade math and we have a cost of $0.44 per wh. This means that I can buy a battery right now from Harbor Freight that is more economical to power a car or anything else than what Tesla had published as their "goal"!!!!
You have to ask, "Who is minding the store?" when it comes to investing tax money into electric cars when the battery from Harbor Freight at retail has a cost less than that being promised by Tesla. Where are all the electrical engineers that we have graduated in the last 50 years? Why don't they speak up and pull back the curtain?
PS----I checked the latest on Tesla's battery and found that the price of their battery works out to really be $0.75 per wh rather than the $0.50 that I showed above. That still makes the Harbor Freight battery at $0.44 per wh has a cost of almost half that of the Tesla battery. Where is all this Tesla technology anyway? The Tesla battery is made up of 6,831 Lithium-Ion flashlight batteries that each can store 7.75 wh and have a cost of $5.85 each for a total price of $40,000.
