# "StealthBus" - 1973 VW Bus EV conversion



## chivey (Jun 18, 2009)

First wheels up test of the complete controller / drive train - very excited.






Many more EV grins (and evil laughs...!) to come I think...

-Chivey


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## Guest (Oct 26, 2009)

Excellent. Nice to see another VW conversion. Did you go with the clutch? I assume you did as the VW is not the best for shifting without one. 

Pete 

Waiting for more video and some wicked laughs


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## chivey (Jun 18, 2009)

Hey Pete

Yes I did use a clutch, I decided use one more from a "what if something shorts out and I have 100kW motor trying to beat my right foot on VW bus brakes" perspective. 

Nice Ghia by the way. I'm planning to hot-rod black the bus and drop it to frame (w/airbags) once the major EV engineering is road tested for a couple of months.

-Chivey


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## chivey (Jun 18, 2009)

Road Test !!! - Very big EV grins....!


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## Guest (Dec 1, 2009)

Excellent job. Another VW on the road. Super sweet.

Pete


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## DavidDymaxion (Dec 1, 2008)

It's uncanny to see a VW van moving without the clatter of the air cooled motor!


gottdi said:


> Excellent job. Another VW on the road. Super sweet.
> 
> Pete


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## DONEAL (Sep 10, 2008)

Great build? I always thought the VW bus was cool. (got to be careful, I’ll give away my age)
I do have one question, What kind of vacuum pump are you using? It look like you was a block away and could hear you coming, or was this some kind of back ground noise in the video? Even with the pump noise It’s still a lot quieter than the old ICE they had in them. I really like your EV VW Bus and you did a great job documenting your steps in the build.


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## chivey (Jun 18, 2009)

The vacuum pump is the kit from EVsource, and wasn't actually wired up for the test run... so yes just background noise - it was the shop compressor decided it needed to recharge right at that moment


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## chivey (Jun 18, 2009)

Connected the vacuum pump up, now it stops even better!

Did first major on road test - 25 miles from the workshop to home.

No issues! - Grinning all the way. Video coming soon.
Started at 156v, read 143v back at home - that's right around 50% DoD
Did start to notice serious voltage sag on the last 2 miles or so (down to 100v on the gauge when really pushing it - i.e. over 200A), the moment I let off the needle jumps back to 135v-140v ish. guess that is normal???

- Pete (aka chivey)


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## chivey (Jun 18, 2009)

Video of trip home - 25 EV (s)miles

- Chivey


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## Guest (Dec 14, 2009)

Chivey,

Sweet. Thanks for the video. Smiles by the Mile  What was your average speed on that run? 

Pete


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## chivey (Jun 18, 2009)

Hi Pete,

I was averaging 30-40, mainly due to traffic. Got to a top speed of 60. Was really trying to be gentle to the motor/batteries, I kept the amps under 200 most of the time and stopped every couple of miles to make sure nothing was hot or loose.

Just need to figure out my PFC-30 charger setup, I think the CI volt cutoff is OK at 172.8 (14.4 x 12), just trying to gauge the CV timer, I think is it set to 15 minutes initially (factory default), I'm going to try moving it out a bit longer 45 minutes 

- Chivey (also another Pete!)


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## rctous (Jun 18, 2008)

chivey said:


> Hi Pete,
> 
> I was averaging 30-40, mainly due to traffic. Got to a top speed of 60. Was really trying to be gentle to the motor/batteries, I kept the amps under 200 most of the time and stopped every couple of miles to make sure nothing was hot or loose.
> 
> ...


check with the battery manufacturer but most deep cycles want to see at least 15 vdc per battery for a full charge. 14.4 may not be giving you 100% charge. 180vdc is normal for 12 x12 vdc batteries in series ( max charge voltage) some "boiling" needs to occur to reduce build up on the plates,, ( now I did not see if you are using AGM cells or something) that is different

Brian


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## chivey (Jun 18, 2009)

Brian,

The batteries are AGM (C&D Technologies MR12-490) 138Ah.
The datasheet states "Equalization and Cycle Service Charging Voltage = 14.4 to 14.8v", so I was starting with a conservative approach. But I understand the risk of undercharging, so would like to try and get the best setup.

I did start a thread asking this question on the battery and charging forum, but either I didn't understand the response or it was just interesting background article:-

http://www.diyelectriccar.com/forums/showthread.php/pfc-30-newbie-charger-question-39569.html

Many thanks,
Chivey.


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## EV-propulsion.com (Jun 1, 2009)

here are some _general_ charging / discharging voltage numbers:
never charge AGM batteries higher that 14.7 each, in your case never charge over 176 volts.
100% charge= 12.65+ volts ea = 152 volts in your case
75% = 12.45 = 149
50% = 12.24 = 147
25% = 12.06 = 144
0% = 11.85 = 142

these are slightly conservative numbers, based on 0% charge (11.85v) being really 80% discharged (which you dont really want to go beyond anyhow) 
I think you were more than 50 % discharged. Closer to your max range.
These are at rest voltages, no load on them.
But always check with your battery manufacturer, as they may have a different max voltage for charging. Generally these are good, safe #'s

Mike
www.EV-propulsion.com


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## rctous (Jun 18, 2008)

chivey said:


> Brian,
> 
> The batteries are AGM (C&D Technologies MR12-490) 138Ah.
> The datasheet states "Equalization and Cycle Service Charging Voltage = 14.4 to 14.8v", so I was starting with a conservative approach. But I understand the risk of undercharging, so would like to try and get the best setup.
> ...


Makes sence now,, as I said follow manufacturers directions, Great project!!!!!!!!

Brian


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## chivey (Jun 18, 2009)

Brian / Mike,

Thanks for your feedback. I'll give C&D a call, and from there figure the best numbers. I'm guessing from the feedback is it will probably a tweak up on the equalization up a bit

And I'll keep an eye on the voltmeter! 

Thanks again,
Chivey.


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## chivey (Jun 18, 2009)

Did my first electric commute today 

Maintained 55mph for 4 miles, hit max of 400A (avg about 150A). Still running default settings on the Logitech controller. At one moment I could smell that tell-tale "electrical hot smell" - which for now putting down new components off gassing... this was the first sustained run at higher current draw.

My commute is 9 miles one-way. The morning run I was at full charge leaving home (measured 155v) and arrived at 149v (I'm estimating about 75% DOD).

My workplace has just installed 2 charging points (110v/20A) so I can recharge at work. Full recharge took about 3 hours (pulling only a modest 12A from the 110v outlet).

Evening run as more or less identical, without the electrical hot smell 

Laterz,
Chivey.


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## Guest (Feb 10, 2010)

Excellent. Glad to hear from you again. Been awhile. That is actually pretty good. Nice work. 

Pete


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## chivey (Jun 18, 2009)

Was rather cold here in GA this morning (27oF), but it was bright and I was keen to drive. Very similar performance to Monday, end voltage of 148.8v (at the office) - slighty different route this morning. Again I did maintain 55 again on the way to work and actually hit 70 taking the longer interstate route home. Very impressed with stablity of the system - no scary noises or arcing... The acceleration could be a little better, I might venture a +1/8 to +1/4 turn on the current limit adjust. Just hit 150 EV miles... and lovin' it.

Chivey.


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## tawright (Dec 30, 2009)

chivey said:


> Did my first electric commute today
> 
> Maintained 55mph for 4 miles, hit max of 400A (avg about 150A). Still running default settings on the Logitech controller. At one moment I could smell that tell-tale "electrical hot smell" - which for now putting down new components off gassing... this was the first sustained run at higher current draw.
> 
> ...


Chivey,
I have a couple of questions. My compute is 32 miles one way all highway (55 - 60 mph) ( my place of work has outlets that I can use to charge from whne at work). Do you think your setup would make this? And can you explain the 75% DOD. I know it was explained somewhere else on the forum but I cannot find it again. 

I plan on converting my 98 Ford Escort so I'm not sure if it weighs less than a VW bus or not.

Thanks
Tom


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## chivey (Jun 18, 2009)

Hi Tom,

75% Depth of Discharge (DOD) for me, based on the generic AGM numbers means each of my batteries is measuring 12.45v or 149v for the pack. i.e. I have consumed 25% of my total available power.

From what I've researched the ideal would be to never go below 50% - for longest battery life.

So that would put me at 18 miles -ish. Now I only maintain 55mph for 4 miles each way, and range inversely proportional to speed as drag is major consumer of your energy.

Now.. the Ford Escort is much more aerodynamic than a VW bus (a house brick is more aerodynamic than a VW bus  )

My best advice would be to look on EValbum and in the DIYelectriccar garage for similar cars and see what kind of range @ 55mph people are getting. Also this calculator page is excellent for evaluating system configuration options: http://www.evconvert.com/tools/evcalc/

For my setup the combination so far the performance is spot on for my needs, in a smaller car if you can handle the battery weight the performance should be much better... but since you need 55mph all the way check the theoretical numbers then compare at with others practical experiences.

Best of luck!
- Chivey.


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## chivey (Jun 18, 2009)

The StealthBus is officially an Alternative Fueled Vehicle!

The official tag arrived in the mail:-


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