# AC Conversion VW Beetle ?'s



## Travdude (May 11, 2009)

Have not seen any kits, but there is this AC beetle:
http://www.evalbum.com/1901


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## EVfun (Mar 14, 2010)

The last couple of motor controller packages over at EVparts look interesting. These motor imitate the business end of an ADC 9 inch motor so commonly available adapters can be used.


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## tavish (Apr 25, 2010)

after reading about that other AC conversion, the range and speeds seem no better at all, isnt AC supposed to improve that? 

saying i was to use this motor/controller
http://www.evparts.com/prod-MT1963.htm
along with t-105 batteries in a 108v config (max for motor) what do you think i could get for range and or speed with regen braking?

if there is not that much advantage i may as well use DC


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## EVfun (Mar 14, 2010)

I'm going to guess you can go about 50 city miles. The old Beetle has the aerodynamic qualities of a brick, so freeway will be noticeably worse (rough guess, 35 miles.) You won't get this range unless the batteries are warm, the terrain is relatively flat, and things like tires suspension and alignment are all correct. 

The AC part of this may add as little as a couple miles to the ideal case, but in hilly terrain where range may drop to 35 miles it could add as much as 10 miles. The VW transaxle was not designed for efficient regen. All AC stuff is a WAG (wild @$$ guess) on my part because I've only read others reports on it. All my work has been with DC motors.


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## tavish (Apr 25, 2010)

mayhap i should switch to a different donor vehicle then? (if so whats nice and cheep, but not that ugley)
or thought 2 is to create a hybred using a generator on a dc system, but how many watts would it take for a 72-120 volt dc system? (or do i need to get more specs?)

thanks


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## Tesseract (Sep 27, 2008)

tavish said:


> after reading about that other AC conversion, the range and speeds seem no better at all, *isnt AC supposed to improve that?*


No, AC only cures cancer and hunger... future versions in development right at this moment may bring about world peace. 

Obviously I am being facetious... More seriously, an AC motor/controller system will, at best, only be a point or two higher in overall efficiency compared to an _equivalent power_ DC system. The only real range advantage you can get from an AC system comes from the ease with which it can do regenerative braking, and that only provides enough of a boost to notice if you have to accelerate and decelerate a lot (ie - stop and go traffic, lots of hills, that sort of thing). If most of your driving is on flat ground and/or at constant speeds (ie - the highway) then regen won't put enough energy back into your battery pack to even notice.

That said, everyone seems to lust after AC anyway, despite it costing several times more per kW delivered than DC. Don't think we at EVnetics are ignoring that peculiarity.


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## EVfun (Mar 14, 2010)

tavish said:


> mayhap i should switch to a different donor vehicle then? (if so whats nice and cheep, but not that ugley)


Well, if efficiency is your primary concern the Geo Metro is hard to beat. They where designed for fuel economy. It's was all about sticking 2 big numbers on the EPA rating tag. I've owned one of them, drove a bit like a Bug even (like a big go-cart that goes where you point it, but not to quickly.) We don't have a lot of economy cars in the USA and I don't think any would be easier to convert than the simple old Beetle. I've owned 4 of them (converted 1 to EV.)


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## tavish (Apr 25, 2010)

okay well now i'm totally in indecision. Thanks  lol. But I really dont know the beetle seems soo straight forward (and can seat 4), and im a bit of a herbie fan too . (i know old movie) But i just dont know. I have a more limited budget so to me simple = cheaper (yeah coming from a guy who wanted to do AC). 

So i guess I would be doing DC then, but here is my question. 

What motor/controller setup to use and what volt configuration, and batteries. Most likely the t-105 (these are better as in range than the 100mah thundersky right?) and range estimate for suggestion on motor. (thinking bout the AXE-7245 for a controller but only 72v max)

And finally thinking along the lines of hybrid and adding a generator (just for some longer trips) what wattage would be required to power the suggested motor?


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## EVfun (Mar 14, 2010)

I would suggest looking at either an ADC 8 inch motor or Impulse 9 (a shorter version of the Warp 9.) The least expensive controller that is suited to the job is probably the Curtis 1231 series. These choices should work in either the Beetle or Metro, though I too am partial to the Beetle. They can prove very efficient at city speeds, the poor aerodynamics really only comes into play above around 40 mph.

If budget is your primary concern golf cart batteries are certainly the cheapest. You will have the added cost of beefing up the suspension (60 to 65 lb. per golf cart battery.) I would suggest looking into 8 volt golf cart batteries. More voltage for the same number of batteries, and that is more suited to building a freeway capable EV. You are correct, one T-105 will get you as much or slightly more range than 2, 100ah ThunderSky lithium batteries.


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## tavish (Apr 25, 2010)

thanks man you have been alot of help !

could you recommend an 8v battery? also range? (arent golf cart batteries most efficient most Mah per volt? or am i incorrect?)

how would i calculate how many watts of power the motor would consume? or im i complete screwed up with the math of electrics lol?

could you direct me to a decent place to get a impulse 9?

and is there a list of components required for a DC conversion? ( i know most just want to spec out everything before going in too deep)


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## EVfun (Mar 14, 2010)

I would recommend one of the Trojan 8v golf cart batteries. Others will likely prefer USBattery, but I have found Trojans to be reliable and consistent (important when you want to string a bunch together.) Exactly which model is an availability thing. Usually, the cheapest way to get golf cart batteries is to contact places that sell and service golf carts. Let them know how many you want, new and from one pallet (matched set for easiest charging), and see what models they are using and what kind of deal they can make. Golf cart lead is the cheapest way to buy range. Range comes down to watt hours, how many amp hours you got times your pack voltage. It is likely the heaviest way to buy range too. 6 volt golf cart (GC) batteries are even cheaper, but low voltage tends to limit motor rpm and so speed. Few freeway capable cars have less than a 96 volt pack.

There are a couple of places where I buy most of my big EV parts. EVparts is where I bought my last motor, but they sell Advanced DC motors instead of NetGain motors. I also buy quite a bit of stuff from EVsource and they NetGain motors instead of Advanced DC.

I think the 8 inch would be a better choice for a Geo Metro because it is possible that a 9 inch motor would have CV joint clearance issues. I would prefer the Impulse 9 for the Beetle because motor length is the first to get in the way. The Impulse has been designed to be a short 9 inch motor. Both have similar continuous power ratings but the 9 may handle even higher peak amps due to a larger commutator and brushes. The last motor I purchased was an 8 inch motor from EVparts for my '66 Datsun. A 9 inch motor was not even an option as it wouldn't clear the front crossmember.


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## tavish (Apr 25, 2010)

hmm is there a vehicle u could use a 48v system in efficiently? (just thinking a li-ion 400mah config) i doubt it would be efficient in a beetle


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## Tesseract (Sep 27, 2008)

tavish said:


> how would i calculate how many watts of power the motor would consume? or im i complete screwed up with the math of electrics lol?


I like this site - HP and Aero Calculator - because the power requirements it predicts match very well with real world data collected from the Soliton1 (disclaimer - I make). Use 0.48 for the Cda and 19.4 ft² for the frontal area of the old Beetle. 




tavish said:


> could you direct me to a decent place to get a impulse 9?


Any NetGain dealer in good standing should be able to get you the Impulse 9. A couple of examples are our sister company, Rebirth Auto, and EV-Propulsion. 

You should also consider Kostov for a motor. Their 9" is a little less powerful than a WarP 9 but lighter, and less expensive. Kostov motors are wound for a higher voltage so need less current for the same power output. The NetGain Impulse 9 is a solid choice, though, so either way you are good.



tavish said:


> and is there a list of components required for a DC conversion?...


I suppose there is somewhere here. The guys at either Rebirth Auto or EV-Propulsion will be glad to help. There is a wide range of parts depending on your performance and convenience goals, but at a minimum you will need:

Motor (w/ tailshaft if you want to use the stock alternator, power steering pump and A/C compressor)
Adapter Plate
Controller
2/0 welding cable (for battery and motor connections)
Fuse(s)
Throttle assembly
Emergency Stop switch and battery disconnect contactor
Batteries
Charger
Hardware to mount batteries!

Good luck. Lots of help available here, and lots of good info archived - just search!


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