So... 691HP. That's 515,278.6 watts assuming 100% efficiency.
Assuming a fully charged pack, and no voltage sag (impossible!), that would be roughly 1300A. Realistically, this would be closer to 1500A.
Either way, the main pack fuse on the 85kWh pack is 630A.
Looking up this part number, this is a fast acting fuse. So, I would think that much over 630A for multiple seconds would pop this fuse.
630A at nominal voltage of 355V is about 225kW, even less than the current P85 draw.
Originally spec'd P85 was 416HP. So, 310kW. That's already 85kW over this fuse's rating.
The P85D, that's 290kW over... more than double even under ideal conditions.
Now, in my testing for my off-grid solar project using the Tesla pack (see thread on this forum for details), I've run this fuse at 410A. It gets *hot* quick. FLIR cam registered it at over 250 degrees fahrenheit. Not enough to pop it, but I'm pretty certain that over 630A would do it.
So, this doesn't add up, for the P85 or the P85D especially. Reaching for explanations...
One might be that the extra juice comes from the precharge capacitors. From my pack tear down, I know there is a precharge resistor, which means there are capacitors somewhere in the inverter/drive unit. Would these be enough to make up for the full power acceleration? Math time...
I've done a top speed run in my P85....... shhhh.... and a manual count was at least 7 seconds of the bar around 320kW. That means 2240000 watt seconds, or about 622Wh for that period. Assuming the pack is delivering the max fuse rating, or around 225kW, that leaves 185Wh that is needed to make up the difference.
OK, so maybe there are 185Wh worth of capacitors somewhere? That's 666,000 joules. That would be about 8.33 farads at 400V... 3333 coulombs.
The best ultracapacitors I could find setup for this would weigh over 100 lbs, and cost somewhere in the $10,000 range... so, this is doubtful.
So... how are they pulling this power out of the pack without popping the main pack fuse? :cursing:
Assuming a fully charged pack, and no voltage sag (impossible!), that would be roughly 1300A. Realistically, this would be closer to 1500A.
Either way, the main pack fuse on the 85kWh pack is 630A.
Looking up this part number, this is a fast acting fuse. So, I would think that much over 630A for multiple seconds would pop this fuse.
630A at nominal voltage of 355V is about 225kW, even less than the current P85 draw.
Originally spec'd P85 was 416HP. So, 310kW. That's already 85kW over this fuse's rating.
The P85D, that's 290kW over... more than double even under ideal conditions.
Now, in my testing for my off-grid solar project using the Tesla pack (see thread on this forum for details), I've run this fuse at 410A. It gets *hot* quick. FLIR cam registered it at over 250 degrees fahrenheit. Not enough to pop it, but I'm pretty certain that over 630A would do it.
So, this doesn't add up, for the P85 or the P85D especially. Reaching for explanations...
One might be that the extra juice comes from the precharge capacitors. From my pack tear down, I know there is a precharge resistor, which means there are capacitors somewhere in the inverter/drive unit. Would these be enough to make up for the full power acceleration? Math time...
I've done a top speed run in my P85....... shhhh.... and a manual count was at least 7 seconds of the bar around 320kW. That means 2240000 watt seconds, or about 622Wh for that period. Assuming the pack is delivering the max fuse rating, or around 225kW, that leaves 185Wh that is needed to make up the difference.
OK, so maybe there are 185Wh worth of capacitors somewhere? That's 666,000 joules. That would be about 8.33 farads at 400V... 3333 coulombs.
The best ultracapacitors I could find setup for this would weigh over 100 lbs, and cost somewhere in the $10,000 range... so, this is doubtful.
So... how are they pulling this power out of the pack without popping the main pack fuse? :cursing: