Question on range electric vs petrol cars.....a techical battery question (1 Viewer)

[Mike375]

As many of you will know with a petrol engine in general you use 15 parts of air by weight to 1 part petrol and thus 3 pounds of oxygen to 1 pound of petrol. I know 1 imperial gallon of liquid oxygen weighs a bit more than 10 pounds and about 8 pounds for petrol but just to make things easy we will assume a gallon of liquid oxygen weighs 8 pounds.

So if we make the car's fuel source completely independent then we need a tank for liquid oxygen and that thank will hold 3 times as much as the petrol tank. Thus for a gallon of petrol we need to carry 3 gallons of liquid oxygen.

If the engine is "tuned" to use petrol at the same rate as when it was an air breather then we will need 4 gallons of the Petrol/LOX mix to achieve the same range as 1 gallon of petrol gives us with an air breather engine and of course as every knows the air breather engine gets the oxygen for "free".

Now to my question. From what I can see a battery is a sealed and self contained unit. Does this mean that irrespective of battery technology the range of the car will always be limited when compared to an air breathing engine?

As a side question on batteries are the batteries in tablets/phones the same type as in laptops?

 

[The_Doc_Man]

As a side question on batteries are the batteries in tablets/phones the same type as in laptops?

Mostly yes, they are in the general family of lithium ion batteries. Best performance on recharge "return" lifetimes. I.e. they can be recharged many more times than other "flavors" of battery such as alkaline or lead-acid. They "personalize" less often than other types of rechargeable batteries. Meaning if you do a recharge after a partial discharge, you are LESS likely (but not 0% likely) to damage the battery in a way that prevents it from ever reaching its original maximum capacity.

From what I can see a battery is a sealed and self contained unit. Does this mean that irrespective of battery technology the range of the car will always be limited when compared to an air breathing engine?

This is an OPINION because I would have to do a survey of available batteries. However, if all other factors are equal and only for the commercially available electric cars about which I have read, I believe your answer is yes. Has to do with the weight of the battery and the fact that you need greater battery capacity to get greater range, but that greater capacity means greater weight which makes the electric motor have to work harder to move the vehicle and thus increases power draw to move the greater rate at the same speed, which in turn reduces range.

This is why so many companies are researching new battery technology. It is a matter of the density of the active surfaces (because for most batteries, the generation of power occurs only on surfaces) and how much weight is required to produce X watt-hours.

 

[Uncle Gizmo]

The YouTube video attached is not directly related to this thread. However I think you will find it interesting!

The most interesting comment I note, was the explanation that battery technology is not evolving as quickly as other technology.

My assumption (everyone's) automatically being that battery technology would motor on like most other tech, doesn't seem likely.

Sent from my SM-G925F using Tapatalk

https://youtu.be/9gRS7PK6TP0