# Hybridize existing EV (range extender)



## KrisBendix (Aug 28, 2017)

Hi.

How would you add a range extender to turn the EV into a hybrid? I will need it for my idea. Existing EV or DIY built/converted.

What I'm thinking is: Range extender -> Ultra-caps -> Motor -> and batteries, if having surplus electricity.
The idea is to use ultra-caps as temporary storage to avoid unnecessary recharging for batteries. Save them a bit.
I don't think existing controllers have that kind of option. Would you use some kind of additional controller there?

I can't specify too much what I need since my idea will adapt to what is possible.


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## Duncan (Dec 8, 2008)

At the moment ultracaps are a white elephant
They need to go down in cost by a factor of 20 and up in energy storage by a factor of 10 to be of any use at all


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## KrisBendix (Aug 28, 2017)

Duncan said:


> At the moment ultracaps are a white elephant
> They need to go down in cost by a factor of 20 and up in energy storage by a factor of 10 to be of any use at all


Even as a small temporary storage? I just wonder about the long term cost savings when it comes to reducing small charging/discharging for batteries. Not sure how much batteries like partial discharge.
Ultracaps could serve as temporary storage for both brake regen and range extender.
So even if they cost more now, maybe in the long run it is worth.


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## Duncan (Dec 8, 2008)

Like I said a cost factor of 20!

You will pay *more* than 20 times as much for the caps

If the batteries last 5 years that is 100 years

Even if the batteries only last 1 year it's 20 years and there will be something much better available well before then


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## KrisBendix (Aug 28, 2017)

Looks like it then, yes.
What about the range extender, anyone has done it? What would be the easiest way to make it work on an existing system?


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## Duncan (Dec 8, 2008)

A number of solutions

Trailers 
- with a load of batteries - used for home power when not behind the car
- with a generator (this is not very efficient)
- pusher trailer - the front end of something like a diesel golf/rabbit that pushes the car along

Batteries or a generator in the car - not normally much room!


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## Karter2 (Nov 17, 2011)

KrisBendix said:


> Looks like it then, yes.
> What about the range extender, anyone has done it? What would be the easiest way to make it work on an existing system?


 What is the planned battery range, and How far do you think you want to "extend" the range ?...20%, 100%, or unlimited range ??
In most cases, its simpler, cheaper, and more efficient to simply increase the battery capacity to "extend" the range, but if you are thinking of having a range extender that can maintain performance once the battery is flat , until the fuel is empty,....then you want to be thinking of a Plug in Hybrid drive instead.
Google the BMW i3 REX.


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## PStechPaul (May 1, 2012)

This was discussed recently in the "over unity" megathread, and I think a reasonable low-cost (and reasonably green) option is a propane powered generator that can be used to recharge the EV's battery pack overnight or during an 8-hour work shift where other charging sources are unavailable. A 4 kW generator is about $400 and will run for eight hours or longer on a 20 pound propane tank. That will give you 32 kW-h of charge or over 100 miles of range, only adds about 150 pounds, and may fit in a good size trunk or a small trailer. A little portable 800 watt generator will give 6 kW-h in 8 hours, or 18-24 miles of range.


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