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Jet Electrica?

2K views 10 replies 4 participants last post by  M640x 
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.
 
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
 
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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