[EVDL List]

[EVDL List]

It has been suggested to me by more than one knowledgeable EV builder that
it's often best to pick your batteries first, then design the rest of the
EV around them. Would you like to go far or fast? Your battery choice will
determine how much energy (range) and power (acceleration) you have
available. It will also allow you to determine what type of vehicle would
be appropriate for a given battery pack size (cost).

Unfortunately, the only two readily available options are flooded
lead-acid and sealed lead-acid. Neither would perform particularly well
for 100km range. Especially with hills or in cold weather.

Consider this:

I have a VW Cabriolet using 19x 6V Trojan T-105 batteries. According to
the "rules of thumb", I should have a range of about 75 miles at 30-45MPH.
In reality, I live in a hilly area and can manage about 30 miles IN THE
SUMMER. When temps drop below 35F at night my range decreases to 15-20
miles.

Average current draw @ 30MPH: 60A
On a slight grade: 125A
On a moderate grade: 200A
On a steep grade: 300A+

While my batteries would last over two hours at 60A, that time drops to
about 40 minutes at 150A and 13 minutes at 300A. It's pushing the 3,400
pounds of car up the hills that eats into my range.

Look at the EV Album (www.evalbum.com) and search for trucks/pickups.
You'll see what typical conversions are capable of. And remember that
completely draining a battery will greatly shorten its life

-Adrian

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[EVDL List]

> Donor vehicle: Suzuki Vitara 2door 4X4
> Batteries: The big question...seems to be the X factor...probably decide

How much room for batteries does this vehicle have? To get the daily
range you are talking about is going to require about 3/4 ton worth of
lead-acid batteries. If you choo$e to go with Lithium batterie$, how deep
are your pocket$?

> Just a couple of other questions...
> 1. Do the DC motors/controllers (ie the parts chosen above) provide regen

No. Series wound motors (like the Warp) don't do regent very well, and
the 'zillas don't do regen at all.

> 2. Researching the debate about DC-DC vs alternator, I think I prefer to
> drive an alternator off the tailshaft of the DC motor,

The alternator is simpler, but incredibly ineffficient. At best it might
be 45% efficient, but most of the time will be running at even lower
efficiency. Compare that to a DC-DC that is at worse maybe 80%.

Plus with an alternator, you voltage drops every time the traction motor
stops. So while driving you voltage might be 14V, but as soon as you come
to a stop it drops to 11.8V or so. Your headlights dim, wipers slow down,
etc.
If you can live with these issues, then go for it.

> 4. I notice some contollers seem to be very noisey (high pitched whine)

The Curtii do this at very low RPMs because they change to a slower
switching frequency. Curtis does this to help keep the controllers from
frying when trying to start up the larger DC motors.

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