Originally Posted by IceThor
I'm from Iceland and this hole idea of EV car is blowing me away.
Nice to see how much life is into this conversion idea and salute to you pioners of ev conversion. With all that said.
You m****s. j/k
Well I've been reading kiwis (NZ) forums and it sounds to my that you guys are just makeing another "who killed the electical car" electrical car!
There is only one way to compair EV car to fuel car and that is by kW's and what do we have in fuel cars 70 - 130kW's . . and you guys are doing 12 - 40 kW's? and fuel car goes like 4-600 km on fuel and your goal is 40 km . . or 60? Common we can do better than that guys . . can't we?
How do we coulculate this? Watts = Amps x Volts, W = A x V
We can find Peek of LA batteries as well as Li-ion batteries.
Some LA (LeadAcid) has max 515 A for 30 sec at 0 C°. 400 Ah Li-ion has 800 - 1000 A continuous and 2000 A max peak? do the math ;-)
My math is 144 x 800 = 115 kW
I'm prolly pissing somebody off here but my goal is to make Huyndai Santa Fe a EV and I want a car that can go 320 km (200 miles) and I want to be able to go no less than 160 km/h (100 mph).
What I need for this is 11 inc motor, 1-2 k zilla converter and 96 - 144 volts 400 Ah Li-ion its ion guys not iron!!!!! ion there is no r there ion.
Yea its expencive but I like to be able to pull my trailer and maby I have to give the trailer extra battery pack to extend the power but I can drive sooo much cheeper so I can pay my bills without any fuel cost!
Now thats what I call EV conversion.
Welcome to the forum, Thor.
First of all, I can hardly believe we are the pioneers of electric vehicles, considering electrics have been around since the late 1800's. Additionally, we are hardly the pioneers of electric vehicle conversions, as this has been happening for at least 30 years.
You have an obvious interest in the subject, and have done some homework it would appear.
PbA (Lead Acid) is limited in energy density, or rather has a high weight to density ratio. They are, however, very resilient, extremely well proven, and quite cost effective.
Other battery technologies, as you mentioned, based on lithium, are lighter and more dense. They are also considerably more expensive, not just for the batteries themselves, but for the Battery Management Systems
and sophisticated chargers.
There are more than one Lithium-based battery technology available, however. All Lithium-based batteries are part of the "family" of Lithium-ion batteries. Perhaps the most common chemistry is known to most of the world is composed of a Lithium Manganese Dioxide (Li-MnO2). Li-MnO2 is a good fit for low-drain, long life and low cost. Another common chemistry is LiFeS or LiFeS2, both of which are used as a replacement for alkaline batteries. These are "Lithium-iron" or "Li/Fe", built with Lithum and Iron Sulfide or Iron Disulfide. The type we all wish we could get a set of are LiFePO4, or Lithium Iron Phosphate. Again, "Lithium-iron". There *is* an r in "iron".
Now, on to some of your other points.
I would like a car that can go 100+ mph, but this is 40 mph above the legal speed on most of the higher-speed freeways in my country. In some places in the country, it is legal to drive as fast as 80 mph, and due to lax enforcement, most of the 60 mph roads also contain drivers going 80 mph or faster. However- just like in an infernal combustion vehicle, if you drive faster, you use more fuel. The faster you go, the more fuel you must throw into the combustion chamber to maintain that speed. The same is true for an electric, the faster you want to go, the more power you will drain from the battery.
Another point was in relation to the power rating of motors- Electric motors behave differently in their power curves to that of an ICE. I've said this for years- people will buy the car with a horsepower number, and drive on the torque curve. Taking my ICE vehicle for comparison, I produce peak torque at 3700 RPM and peak HP at 5500 RPM. How often does the average driver actually drive on the horsepower curve? Not often- most want to reduce their RPMs to run their vehicle more economically. An electric on the other hand produces astounding torque from 0 rpm. Now, the funny thing about horsepower is that it is a number derived from the RPM of a rotating mass and the amount of torque being provided at that RPM.
At the turn of the last century some very impressive engines were designed that could only run around 100-200 RPM, but these were, for example "40 horsepower" engines. At 100 RPM, 40 horsepower is equivalent to 2100 ft-lbs of torque.
Now that this has been said, you will notice that electric motor manufacturers rate their motors for a PEAK horsepower and a CONTINUOUS horsepower. Unlike an ICE, the PEAK horsepower will likely be due to enourmous torque at low RPM, instead of at high RPM. Similarly, CONTINUOUS horsepower will be near the peak efficiency RPM, which is much higher on electric than on ICE.
This is the reason most people find it sufficient to put their vehicle in 2nd gear and drive with it like this. There is ample torque to move the vehicle from a dead stop, and most vehicles' 2nd gear and final drive ratio and tire size permit near-freeway speeds at or near the electric motor's peak efficiency RPM.
You've done some homework. Do some more. You'll find that most people do not have a daily need to exceed the speed limit, or drive half way round the world. In my case, if my conversion only netted me 30 miles range, I could do my entire average daily driving with one charge per day. However, my conversion should net me somewhere between 60 and 80 miles range, which permits me to use it for 90+% of my needs, and never pay a drop to the oil companies (other than transmission and differential fluid changes every 30-50k miles.)
Not telling you it's impossible to design your Kia to operate as you desire- but you will either have to make some compromises in your design goal or shell out enormous sums of money to obtain the quantity and type of battery that it will require to sustain draws of that magnitude for the distance you wish to travel. I couldn't buy enough LiFePO4 batteries to equal my range for less than my entire conversion project will cost with PbA chemistry. And that doesn't even count the BMS or charger systems for use with those batteries. If I wanted to double my range beyond that point, it would still cost more than double the price of my entire conversion project.
You can make it fast, you can make it go far, and you can make it cheap. Pick two.