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Discussion Starter · #1 · (Edited)
Hi guys,

I really want to get into EVs and do it pretty cheaply. I was thinking of picking up a Electrica with a GE 9" motor. Basically these are ideas:

SLA batteries are completely shot so I'd figure out someway of converting it to lithium(hopefully cheaply with like a used Leaf pack??)
Also...the batteries are 100% shot, what would be the best way to test the electronics to make sure the controller and motor work?

Comes with a 9" DC series wound...claims 40hp. Would it be possible to get more peak power out of it, nothing crazy but at least a tad zippy? Guy said it has a new controller so maybe that can be a source there?

Not a daily driver...just a project car. I'm both electrically and mechanically inclined so I don't see this as a huge deal.

What do you guys think?

-TP4by3
 

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Re the motor

40 hp continuous is probably OK - but it's the controller that sets the power - I would have no worries at feeding that motor over 100 hp

The basic P & S controller is 500 amps and 150 volts = 75 kW or 100 hp

I'm feeding my Hitachi 11 inch motor about 500 hp

I like Chevy Volt batteries - about $2000 for 16 kWh
 

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The basic P & S controller is 500 amps and 150 volts = 75 kW or 100 hp
Just to be clear, that's a peak power which will only be delivered at one motor speed (what speed depends on the motor characteristics). Below that speed, the controller limits current and the voltage needed to drive that current is roughly proportional to speed, so power drops off in proportion to speed. Above that peak-power speed, more of the voltage is needed to overcome back EMF so the as the speed increases current drops off, and so power drops.
 

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Discussion Starter · #4 · (Edited)
Re the motor

40 hp continuous is probably OK - but it's the controller that sets the power - I would have no worries at feeding that motor over 100 hp

The basic P & S controller is 500 amps and 150 volts = 75 kW or 100 hp

I'm feeding my Hitachi 11 inch motor about 500 hp

I like Chevy Volt batteries - about $2000 for 16 kWh
The motor seems to be a GE 9", but its from the early 80s so I can't find any info on it. Can I safely assume its pretty close to a Netgain Warp9 in terms of what it is capable of?

The stock car said it came with 23HP(with stock controller), the guy says it makes 40 now(some controller from the 90s...from the images its says Curtis PMC). I'm guessing thats continuous power? I'd think about 150HP for like 7-8 seconds so that it can be fun to 60 and decent for short on-ramps.

Chevy volt batteries are pretty much the ideal packs, thanks for the suggestion! What is the best place to source these, preferably local pickup. It's a 120V system, so supposedly I can take the individual 48V packs out and rewire into a 3s config, probably 3s2p? Given its a project car, range is not super important but like 50 miles would be nice to take it somewhere. Maybe throw in more cells when I need/want them.

It seems I can get a 2012 pack within local pickup range for 1500$, is this a good idea?
 

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Chevy volt batteries are pretty much the ideal packs...
It's a 120V system, so supposedly I can take the individual 48V packs out and rewire into a 3s config, probably 3s2p?
"120 V" is presumably the nominal voltage for a 60-cell (e.g. 10 "12 volt" batteries, or 10S(6S)) lead-acid pack. There is no nominally 48-volt module in a Volt pack; you're probably thinking of the 12S modules, which are nominally 45 volts (at 3.75 V/cell), so three would be 135 volts. Just consider the extremes of the pack voltage range, which would be about 148 V for that 3S(12S3P) Volt combination (at the 4.11 V/cell assumed by GM), while a nominally 120 V lead-acid pack would sit at about 127 V fully charged, and make sure that's within the controller's allowed range.

VOLT_BATTERY.pdf
 

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Discussion Starter · #6 · (Edited)
"120 V" is presumably the nominal voltage for a 60-cell (e.g. 10 "12 volt" batteries, or 10S(6S)) lead-acid pack. There is no nominally 48-volt module in a Volt pack; you're probably thinking of the 12S modules, which are nominally 45 volts (at 3.75 V/cell), so three would be 135 volts. Just consider the extremes of the pack voltage range, which would be about 148 V for that 3S(12S3P) Volt combination (at the 4.11 V/cell assumed by GM), while a nominally 120 V lead-acid pack would sit at about 127 V fully charged, and make sure that's within the controller's allowed range.

VOLT_BATTERY.pdf
I don't have specifics on the controller pasts its an aftermarket Curtis PMC unit. I will have to check that. I was talking the 12s modules. Aren't there are also 6s ones too? That might work better depending. 5x6s would be 123V max but then the lower extreme would be pretty weak. 99V instead of 108V on the SLA pack.

Also...under heavy power draw, wouldn't the pack voltage drop....so it shouldn't it be advantageous to have a few volts overhead for internal resistance?
 

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I don't have specifics on the controller pasts its an aftermarket Curtis PMC unit. I will have to check that.
Curtis Instruments posts lots of technical information, and there are lots of copies online from other sources... but you need the specific model number.

I was talking the 12s modules. Aren't there are also 6s ones too? That might work better depending. 5x6s would be 123V max but then the lower extreme would be pretty weak. 99V instead of 108V on the SLA pack.
Yes, the first generation Volt pack has seven 12S modules and two 6S modules; as long as they are all in series, you can mix and match to reach your desired pack voltage. Since there are only two of the 6S modules per pack, and the usual source is to buy salvage packs, 123 VNOM / 123 VMAX would be more practical to get as 2x12S + 1x6S. You could even assemble two of those strings, then parallel double the energy capacity, using all but one 12S module from a complete Volt pack.

Also...under heavy power draw, wouldn't the pack voltage drop....so it shouldn't it be advantageous to have a few volts overhead for internal resistance?
Yes, voltage will drop under load, but less than with lead-acid. More voltage is generally more useful than less... as long as the controller can handle it. :)
 

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Discussion Starter · #8 ·
Curtis Instruments posts lots of technical information, and there are lots of copies online from other sources... but you need the specific model number.
From my guest guess it appears to be a Curtis PMC 1231 or 1221 controller, which exactly I don't know. Claims to be either a 96V-144V 500amp or 72V-120V 550amp system. Does this rule out using higher voltage batteries? Of course I can always get another controller but that adds to the cost... Also, is it a good controller?
 

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Hi
The volt battery is a number of modules - a 2012 will be seven 2kwh 12S modules and two 1kwh 6S modules

The 12S are 42v - 49v - (Empty to full) - sensible range - you can go a bit higher and lower
The 6S are 21v - 24.5

It's easy to mess with at "module level" - at "cell level" it's very difficult

So mix and match!

Look on the Curtis site for the MAX voltage that they are happy with

You could use two strings of three 12S - which will give you 147v (max) and 12 kWh
Which would leave one 12S and the two 6S modules left over
 

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Discussion Starter · #10 ·
Hi
The volt battery is a number of modules - a 2012 will be seven 2kwh 12S modules and two 1kwh 6S modules

The 12S are 42v - 49v - (Empty to full) - sensible range - you can go a bit higher and lower
The 6S are 21v - 24.5

It's easy to mess with at "module level" - at "cell level" it's very difficult

So mix and match!

Look on the Curtis site for the MAX voltage that they are happy with

You could use two strings of three 12S - which will give you 147v (max) and 12 kWh
Which would leave one 12S and the two 6S modules left over
12kwh would be likely good enough for the meanwhile. Really its probably not going to be much more than a car show project car and maybe take people for some nice electric pedal mashing highway pulls! Maybe later if I need it, I can buy another volt pack and add another 3s2p for 3s4p.
 

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I used to have a Jet electrica. I had the one that was based on the Mercury lynx / Ford escort. Mine had a Curtis 1221 c controller. I had the 96 volt version and while it was slow it actually drove very well. The 120 volt versions have a lot more pep. If you go with lithium batteries you'll lose approximately 800 to 1000 lb. The performance and the range will increase a good bit.
 
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