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Discussion Starter #1
This is my first EV. This is what I have.

1991 Isuzu pickup
Warp 11
Curtis 80v 600amp controller
20kw battery bank
I am trying to do this on a budget.

1. I can upgrade controller now or later.
I would like to get up to 75mph and its 40miles round trip to work. And
yes there are hills.
2. So I have to choose a charger voltage in order to buy a charger. So what
would be a good voltage to run at in order to get to work and back? I can
enlarge my batteries in order to go further. (I was hoping to use my
current controller and then up the voltage later, but I want a charger.
Seems they have to be reprogrammed. So whats the cost of
reprogramming it.
3. I was looking at getting an elcon pfc4000 or elcon tc 6.6kw Charger.
I work 12hr shifts so, I need it to charge within 11 hrs. I have a 220 plug.
Are these good, or do you have something else that dosent cost 2k$

So, if you could give me some direction, I would appreciate it.
David S
DiyDave
 

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1. I can upgrade controller now or later.
I would like to get up to 75mph and its 40miles round trip to work. And
yes there are hills.
This does not mesh with...

2. So I have to choose a charger voltage in order to buy a charger. So what
would be a good voltage to run at in order to get to work and back?
... that.

The charger, how fast you charge, what voltage you run at, etc, have no zero impact on your range (unless you're saying you'll be charging at work?).

Your range is determined by the capacity of your battery pack and the rate at which you use it. The faster your travel, the more power you use per mile.

You want 40 miles of range on a 20kwh battery.

20,000wh/40 miles = 500 watt-hours per mile.

If you can build a vehicle that only uses 500 watt-hours per mile at 75 mph, you're fine. If not, you won't get there.

75 mph is signficantly more power hungry than 60 mph.

At 60mph... if it's one of those really small trucks, you might get away with 500 watt-hours per mile, but it'll be close. 75 is probably not going to get the range you want.

I can enlarge my batteries in order to go further. (I was hoping to use my
current controller and then up the voltage later, but I want a charger. Seems they have to be reprogrammed. So whats the cost of reprogramming it.
I don't know what it costs to reprogram a charger, but again it seems you're equating a charger to better range.

3. I was looking at getting an elcon pfc4000 or elcon tc 6.6kw Charger.
I work 12hr shifts so, I need it to charge within 11 hrs. I have a 220 plug.
Are these good, or do you have something else that dosent cost 2k$
Well if you're adding 20,000 watt-hours to a charger in 11 hours, then it requires a charger that is: 20,000 watthours / 11 hours = 1818 watts. That's almost exactly a maxed out 120v circuit. On a 220v circuit, your'e fine.

That's a small battery pack and small power demands. Any 2kw charger designed for that output voltage should be fine. A 6.6kw charger would charged up the battery in 3.5 hours.
 

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Discussion Starter #3
Very grateful for answering.

So, I really want to know what voltage I should run at in order to get up to 75, 80 mph. I didnt know what the consumption of current the motor would be, at the higher voltage.

1.what voltage do I need for 75,80mph (1991 isuzu pickup, 3500lb)
2.what capacity approximate will I need for 40miles to work and back,
no charging at work for now. figure 60 miles to be safe. we have hills in
chattanooga tn. I will get more know and buy more later when I can afford
them, if thats ok to add.
3 is elcon pfc 5000 good, ok, bad? I do have 220v ac power.

Thanks for the help. I should have said this first.
diydave
 

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1.what voltage do I need for 75,80mph (1991 isuzu pickup, 3500lb)
It depends on the motor. 80mph is going to take, rough guess, 20-25kw. And double that to climb a steeper hill (which you wouldn't spend on the drive home, but which you would need the power available to climb).

But, doesn't matter. The controller will feed the motor whatever voltage you tell it to, up to the battery voltage. At battery voltage it's on 100% of the time, so there's no way to boost it higher (unless it's designed for that, which, without even looking, I'm pretty sure it wouldn't be).

Your controller you say is 80v max, 600A. (80x600 = 48,000 watts).

So, I would build an 80v pack. No reason not to build it to the max, the controller can always feed the motor less (that's what it does).

The Warp11 is rated for 192v, so, if you had a different controller you could go as high as that, but, you don't, so, 80v it is.

Your motor and controller are probably fine.

2.what capacity approximate will I need for 40miles to work and back,
no charging at work for now. figure 60 miles to be safe. we have hills in
chattanooga tn. I will get more know and buy more later when I can afford
them, if thats ok to add.
I sort of answered this above. You won't know until you measure, but, I'd say 20kwh is barely enough to get you 40miles at 60mph, if it's a smaller truck. If you want 60 miles (1.5x as much as 40) then you'll need a 30kwh pack (1.5x as much as 20kwh).
 

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Discussion Starter #5
Thanks Matt
I am willing to upgrade to a newer controller.

1. I can upgrade controller now or later.
I would like to get up to 75mph and its 40miles round trip to work. And
yes there are hills.
With my inexperience, I just dont know voltage it will take to get up to 80.
So, my question is what voltage will it take.

Thanks

I guess I could get a voltage stretcher.

David S
 

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Hi Dave

With a Hitachi 11 inch motor and 130 volts I was limited to 100 kph (60 mph)

At that voltage the controller was 100% but it would only push 200 amps through the motor - with my Device's dubius aerodynamics that was 100 kph

If you want 75 mph then you will need over 150 volts
 

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If you want 75 mph then you will need over 150 volts
Couldn't he just gear it harder so it pulls more amps, has lower counter-emf from the slower motor speed, and get it working that way?

Like, the controller has enough power, the motor has enough power, shouldn't it just be a matter of forcing the motor to work as hard as it needs to to pull the right amount?

80v in general is... low for an EV. Even for an old lead-acid EV from 10 years ago.
 

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Couldn't he just gear it harder so it pulls more amps, has lower counter-emf from the slower motor speed, and get it working that way?

Like, the controller has enough power, the motor has enough power, shouldn't it just be a matter of forcing the motor to work as hard as it needs to to pull the right amount?

80v in general is... low for an EV. Even for an old lead-acid EV from 10 years ago.
You need the 150v if you are using normal automotive gearing - I'm using a 4.1:1 diff and 15 inch wheels - 17's with the sticky tyres

Going significantly lower than 4:1 is difficult and the bits are expensive
 

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Hi there, the guys who have answered you so far are correct. But, the two answers need to be combined.
Your top speed is completely controlled by the gearing and rear axle ratio, and the tire diameter you will be using. You keep mentioning the truck you have so you can find all that info easily.
Keep in mind that tire size can be chosen to reduce or increase your final ratio by a few percent if needed.
I assume you are not using any gears, ie; a direct drive connection to the tail shaft.

Standard WARP11 Specs
Continuous RPM: 5,000
Max RPM: 8,000

The way I read this you want to keep your RPM to 5000 or less, and that works really well with your stock rear end gears and tire size. (because the old ICE engines usually redline at about 5000RPM) It should give you something like stock speeds. That should be approaching your 75mph goal. The down side as was pointed out earlier, the faster you go the faster you use your battery up. You may find that you can make the 40mile roundtrip by going a slower speed. If you want fast then you need more battery and a controller that can push the volts and current. The motor will do it, it just needs the juice.

And the juice is the expensive part. So you need to make a decision, fast and more battery and bigger controller with a large charger or
the battery and controller you have with a lower speed and a smaller charger.

Pretty much what you didnt want to hear I guess. Want speed? then show me the money!

As for motor voltage and current, you will have to look them up based on the part number of your motor. You will get a voltage current graph and a max voltage before you exceed the motor insulation. I am not sure but I think the WARP 11 max V is 190volts. The more volts you feed her the faster she will spin. The current you feed her produces the torque. You need lots of torque to go really fast. So, if you want to go fast, with a poor aerodynamics, heavy truck, then you need lots of volts and lots of current.
cheers, Mick
 

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But, the two answers need to be combined.
You're right on the rest of it, but this part I disagree. They are separate problems that can be solved separately and independently.

1 - Range is exclusively a battery issue. It's solved 100% by using enough batteries.

2 - Top speed would be a motor power issue, except that it's not, we know the motor's plenty powerful. Top speed might be a controller power issue, except that it's not, we know the controller is plenty powerful. The only remaining issue is gearing, which, as Duncan points out, is hard to solve using standard automotive stuff. Which means he probably should solve it electrically by changing the voltage. Motor is fine for higher voltage. Batteries can be reconfigured to just about any voltage. But controller is already maxed out.

So, controller or gearing has to change.
 
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