# Planning Mercedes w202 EV conversion



## lsy388 (Jan 23, 2019)

Hi, I am new and would like to ask favor to guide for my Mercedes w202 EV conversion. I am planning to do the EV conversion at least up to 200hp, kindly advice, thanks.


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## brian_ (Feb 7, 2017)

You're in the right section now. 

But what do you want advice on? No one is going to design your whole conversion for you, so what have you already decided (other than the car to be converted), and what do you want advice on?


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## lsy388 (Jan 23, 2019)

Hi Brain, i am panning to do the ev conversion with around 250hp, wht kits do i need for the conversion?


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## brian_ (Feb 7, 2017)

lsy388 said:


> ... i am panning to do the ev conversion with around 250hp, wht kits do i need for the conversion?


As far as I have seen, there are no useful complete kits. You need to choose each component to suit your car and your requirements, and ensure that they work together.

So knowing that you want 250 hp, you can choose a motor that powerful, a battery that can supply what that motor needs, a controller/inverter compatible with the motor and the voltage, and the many other parts to put them all together.


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## lsy388 (Jan 23, 2019)

Hi, i got my motor and controller as attachment, just need to know what other components do i need for the conversion and also specification to match my motor and controller. Thanks


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## brian_ (Feb 7, 2017)

lsy388 said:


> ... i am panning to do the ev conversion with around 250hp...





lsy388 said:


> Hi, i got my motor and controller as attachment...


You say you want 250 horsepower, but the motor you have chosen can only put out 25 kW (34 hp) continuously and 55 kW (74 hp) at peak.


This appears to be one of a "Alpha" brand series of motors listed in Alibaba. Some much larger models in this series can put out 250 hp, but the APEV10 certainly cannot, and the ones capable of 250 hp weigh five times as much.


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## lsy388 (Jan 23, 2019)

May I know what is the difference in between electric motor HP and gasoline HP? As i thought electric motor HP is higher than gasoline HP.


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## Emyr (Oct 27, 2016)

lsy388 said:


> May I know what is the difference in between electric motor HP and gasoline HP? As i thought electric motor HP is higher than gasoline HP.


The HP is the same, but electric motors give full torque from 0 rpm, whereas combustion engines usually don't have max torque below about 50% of max rpm.

You can run an industrial motor above rating because they're rating it for 24/7 usage. If a motor is advertised as an EV motor, they're probably quoting the rated power for a shorter period of time, because that gives more impressive numbers.


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## brian_ (Feb 7, 2017)

As Emyr said, there's only one meaning of "horsepower". It is just a unit of power, like "watt" is a unit of power. Power is the rate of doing work or delivering energy, but if you don't already know that it's time to do some reading.

Motors and engines are rated under different conditions. That's what the "continuous" versus "peak" difference is about: the electric motor in the link can briefly put out 55 kW (74 hp), but it will soon overheat at that power; it can only sustain 25 kW (34 hp) continuously. Car engines are rated for what they can continuously sustain.

There's also that factor of speed. The charts with the linked motor show a typical characteristic for a high-voltage AC motor: it can produce its maximum torque from zero speed up to a rated speed (3,000 rpm for the smallest motor of this range, the APEV10), then it can produce the same maximum power at any speed from the rated speed to nearly the maximum speed. Other types of electric motor (such as the brushed DC "forklift" motors) have much less useful speed ranges. Engines produce their peak torque over some part of the middle of their speed range, and need to run faster than that to produce maximum power.

The extra speed flexibility of a suitable electric motor (which the right battery) means that the motor can produce maximum power over a wide road speed range without changing transmission ratios. Since modern automotive transmissions have 8 to 10 ratios and shift automatically, this isn' a performance problem for engines; however, people comparing poorly driven cars with engines and manual transmissions find that the speed flexibility with an electric motor appears to give them more impressive performance.

So, for an example, if an engine can produce at least half of it's rated power over a wide speed range, and it doesn't have a good transmission or a good driver, it might perform about as well as an electric car of the same weight with an electric motor rated at about half of the engine's rating.

For practical examples
the Chevrolet Bolt has an electric motor rated at 200 horsepower, and is about as quick as a modern engine-driven car of similar weight and perhaps slightly higher rated engine power - not advantage to the electric.
Tesla Model S Dual-motor cars are rated at several hundred horsepower, and are about as quick as gas engine cars rated at several hundred horsepower

So if you want the performance of a 250 horsepower gasoline engine, you need an electric motor which can produce almost 250 horsepower (at least peak, if not continuous). In the series of motors in the link, that's the APEV80-12, which needs 540 volts and weighs 260 kg. But you are not building a truck...


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## brian_ (Feb 7, 2017)

Emyr said:


> If a motor is advertised as an EV motor, they're probably quoting the rated power for a shorter period of time, because that gives more impressive numbers.


The linked APEV motors are claimed to be for "Bus, Truck, Passenger car", but appear to be suitable only for industrial vehicles (in the smaller sizes) and buses and trucks (in the larger sizes). Duration for peak ratings is not provided.


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## lsy388 (Jan 23, 2019)

Is it bothering if my car is running with automatic transmission?


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## DrGee (Aug 22, 2018)

lsy388 said:


> Is it bothering if my car is running with automatic transmission?


In a word, yes. Don't use an automatic transmission, as you will lose power in them. Much more preferable to use a manual transmission or if you can find a motor large enough, you can skip using a transmission altogether. The professionals on this forum can tell you a lot more about this than me.


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## Yousef (Dec 13, 2021)

Hello everyone 
I'm a novice with no knowledge on EV, but an electrical engineer in the field of PV solar power plants. I love this exact car model, and I love EV conversion. I have an end goal to make an EV conversion business in my home country Jordan.
the goal of this business is:

making affordable EVs for the lower class, in terms of income, as these people can't afford the starting price of a new car in my country, and they deserve to drive a good car and be able to save money.
helping the transition in my country to greener alternatives.
the end goal is to make EV conversion so popular and easy that I can see competition everywhere.
but as I already said I'm still a newbie, so can some one point me to where to start and if you are interested in keeping in touch so am I.
have a wonderful life every one.


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