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414 Posts
Our cells are for real high power to weight ratio OR low heat build up. "Long course" land speed racing is a lot like hill climbing... long sustained high power.
We would be competitive if weight or volume was THE issue. As true long course racing is not really that weight sensitive, it will be a close call. At 1.5 mile and shorter it truly is a drag race, ask Frank "200mph club" John.
I would suggest 4P108S about 128lbs about 1.5 cubic feet.
Remember to account for motor plus controller efficiency. I hear some folks quote me the motor output power of say a YASA P400 at 160kW which you will note it only makes at about 1/2 peak rpm and the motor efficiency is about 84% at that point. counting controller and cabling, contactors, fuses, efficiencies can hit 80% even on a AC motor system. So the 160kW becomes 200kW at the battery. That's why I always quote "batteryhorsepower".
Also another common mistake is to use the motor peak kilowatts and assume it will make it at peak rpm.
Another common mistake is not comparing sag voltage
A 3.2V 5C cell pulling 20C might sag to 2.0V
Whereas one of my cells pulling 20C would be nearly 3.8V
I admit I don't test to 90 seconds a lot because we were melting Derek's load bank. But we could test them for performance if you need. Here are a few test curves out to near 100seconds. That's high current from second zero BTW.
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Lastly, as far as safety, a 1000lb tesla battery inside an armored case impervious to road debris takes about two fire trucks of water to "put out" and burns all night long without it. A 100lb plastic cover pack on the other hand while a little more dramatic, can be cooled directly if built properly with 10 gallons of water (I know).
You guys going to have a transmission? I would be happy to sharpen the pencil.
We are thinking about trying to be first to 300mph on the Texas Mile LSR course. I have a plan.
We would be competitive if weight or volume was THE issue. As true long course racing is not really that weight sensitive, it will be a close call. At 1.5 mile and shorter it truly is a drag race, ask Frank "200mph club" John.
I would suggest 4P108S about 128lbs about 1.5 cubic feet.
Remember to account for motor plus controller efficiency. I hear some folks quote me the motor output power of say a YASA P400 at 160kW which you will note it only makes at about 1/2 peak rpm and the motor efficiency is about 84% at that point. counting controller and cabling, contactors, fuses, efficiencies can hit 80% even on a AC motor system. So the 160kW becomes 200kW at the battery. That's why I always quote "batteryhorsepower".
Also another common mistake is to use the motor peak kilowatts and assume it will make it at peak rpm.
Another common mistake is not comparing sag voltage
A 3.2V 5C cell pulling 20C might sag to 2.0V
Whereas one of my cells pulling 20C would be nearly 3.8V
I admit I don't test to 90 seconds a lot because we were melting Derek's load bank. But we could test them for performance if you need. Here are a few test curves out to near 100seconds. That's high current from second zero BTW.
Lastly, as far as safety, a 1000lb tesla battery inside an armored case impervious to road debris takes about two fire trucks of water to "put out" and burns all night long without it. A 100lb plastic cover pack on the other hand while a little more dramatic, can be cooled directly if built properly with 10 gallons of water (I know).
You guys going to have a transmission? I would be happy to sharpen the pencil.
We are thinking about trying to be first to 300mph on the Texas Mile LSR course. I have a plan.
