# [EVDL] Anyone done an upgrade on a Citicar/Commutacar??



## EVDL List (Jul 27, 2007)

Lee mentions that the Citicar was near 1300 lb, nearly double the weight of=
the ICE Berkeley (680 lb.) But that's the Citicar with what-- 8 lead ac=
id batteries, each weighing close to 70 lb? Take out that and you have a ba=
sic platform-- alu frame and plastic panels-- that's 800 or a bit less. =
The reason I'm asking if anyone has done an upgrade incl lead- to-litjhium =
is to find out what makes sense for a car that will weigh well under a half=
-ton incl. batteries. Esp whether 60 works well enough, or 72, or even 84Vo=
lts. Anyone done such an upgrade?

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## EVDL List (Jul 27, 2007)

I've owned a CIticar for a number of years, and at 48 volts it will do about 37 
MPH on a flat road. It doesn't seem to make much of a difference in top speed 
to have somewhat more weight (a passenger) or somewhat less weight (four 12v vs. 
six 8v vs. the stock eight 6v batteries). IMHO the top speed in the Citicar is 
mostly limited to the amount of speed you can get out of the motor considering 
rolling resistance and aero drag. Another (but of equal importance) 
consideration is the gearing you have. 


The current weight of my Citicar is 1,160 lbs, using six US8VGC 8v batteries. 
This is slightly less than the stock 1,300 pounds or so.

If you want to get to 60 MPH, you'll have to determine if your gearing and 
motor can ultimately go as fast as you want it to go, regardless of the voltage 
you decide to use.

The absolute top speed is then limited by the gearing of the direct-drive rear 
end. In my CIticar, with a 7.125:1 axle (stock) the motor is turning about 
3,200 RPM at 30 MPH. At 45 MPH, the motor is turning about 5,000 RPM, which is 
probably the limit for this old motor. 


I performed a test at 64 volts (actually 66 - added three 6v batteries in 
series) and the Citicar woke up considerably compared to 48v. Although other 
problems prevented me from getting to top speed during the test (brush link 
insulation gave out, melting the link at about 41 MPH...) it was still 
accelerating well up to that point, and could likely have met the maximum @ 45 
MPH.

Weight does make a difference in acceleration. Acceleration went from about 7.2 
seconds to 25 MPH, to about 5.4 seconds to 25 MPH. This includes the extra 150 
lbs of batteries I was carrying. One of the Citicar owners on the Citicar list 
has done a Lithium conversion to 60 volts, and is happy with the result.

If you have a newer Citicar with a Spicer/Dana rear end, the gear ratio is 
probably 5.17:1, allowing an ultimately higher top speed. 


In my Citicar, higher voltages (keeping the amps the same) will result in faster 
acceleration, but the top speed will always be limited to the maximum RPM the 
motor can handle.

The vehicle itself may or may not be particularly happy above stock speeds, 
however!

Tom Keenan




----- Original Message ----
From: L. Chris Hager <[email protected]>
To: [email protected]
Sent: Tue, April 26, 2011 8:19:53 AM
Subject: [EVDL] Anyone done an upgrade on a Citicar/Commutacar??

I'm not doing one myself, but am considering a conversion to electric of a 
similarly light car, a '50s 2-seat Berkeley, an English sports car weighing 
under 700 lb complete with its I C motorcycle engine, or about 550 without motor 
and tranny. I'm aiming at a 60+ mph car for short runs with a 40 mi mixed-speed 
range. Seems like the city/commutacar, with 36 or 48 v (except the van version 
with 72) would have a similar empty (lead-free) weight. So I'm wondering if 
anyone has done (or can point me to an article on) a conversion to Lithium, at 
72, 84 or 96 v? All advice that comes of experience will be appreciated. 
-Chris in Virginia-- the DC 'burbs

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## EVDL List (Jul 27, 2007)

> On 26 Apr 2011 at 17:21, Tom Keenan wrote:
> 
> > The vehicle itself may or may not be particularly happy above stock speeds,
> > however!
> ...


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