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Hey folks,

This morning traveling over the Altamont Pass here by Livermore, CA, I was re-generating the battery thanks to the massive downhills. When I left my house, my battery showed a range of 41 miles. When I ended up in downtown Livermore, the battery showed a range of 55 miles. It was fluctuating between 52 and 55. Vehicle Car Mid-size car Toyota prius

I've never seen it that high before!

Is there a theoretical max of what the battery range can actually show? Anyone know?

Thanks!

P.S. Sorry about the crappy picture. I couldn't figure out how to turn the flash off on my new phone... :)
 

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Since we are talking theoretically, if the software is using a byte integer data type (8-bit) for the battery range, then it could show 127 miles. An unsigned byte could show 255 miles. If they used a short integer, then 32,767 miles (or 65,535 miles unsigned).
 

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That is interesting..

I think the real question is by how much can you overcharge the battery. On its face, you did that with regen input, going above the wall cutout SOC. The system normally allows an increase of 10kWh from a wall charge and ends the charging..disconnects the inverter.

Some other members have gone well over 50 miles in a downhill run, but I don't know what their estimated range was during the run.

But, IF you could get to the full capacity that would be 13.6kWH above the lower buffer. At that point you would be at the battery's full 16kwh capacity and the input would heat the battery but not increase charge. I am going to guess the software would cut off the regen before the battery got hot.

Alternatively it was bouncing off the programmed SOC limit, reseting, and raising the estmate.

If it kept charging its not good for the battery. To make it worse, regen can get up 17kw which is a high charge rate.

I have never seen more than a 50 mile range on mine. The SOC PID is a byte 0 to 255 covering 0 to 16kwh.

Was your 41 miles a full charge when you left?
 

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I don't think we've determined what is the max estimated range displayed on 2013's yet.

Shiranpuri is correct that the computer in 2011's and 2012's would cap it at 50 miles. I've gotten my 2013 as high as 54, and your reported 55 is the highest I've heard of otherwise.

Maybe there's a crazy hypermiler amongst us that regularly gets more per charge than that and can let us know if the display goes higher. :)
 

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Whar are the limits o regen charging?
 

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There should be two parts to the range projection equation, 1) amount of energy stored in the battery, and 2) rate of energy consumption (energy used per mile driven). I'm pretty confident that the amount of energy that can be pushed into the battery through regen is capped. So the higher range projection numbers may be heavily flavored be the low energy consumption rates as you descend long grades.

VIN # B0985
 

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There should be two parts to the range projection equation, 1) amount of energy stored in the battery, and 2) rate of energy consumption (energy used per mile driven). I'm pretty confident that the amount of energy that can be pushed into the battery through regen is capped. So the higher range projection numbers may be heavily flavored be the low energy consumption rates as you descend long grades.

VIN # B0985
Any idea how and at what level the regen is capped?
 

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Any idea how and at what level the regen is capped?
Depending on what you're looking for, there are two caps. Instantaneous regen is capped at 60kW, which the car protects by switching to the mechanical brakes. Total regen is capped by the battery's upper SoC limit. When the car hits that, it stops doing regen. If you're still descending a hill in L, the car will do a power cycle between MG A and MG B to dissipate energy as heat (MG B regenerates 30 kW (using ~35 kW of potential energy to do it,) and MG A pushes those same 30 kW back to the road ( generating ~25 kW of kinetic energy,) thus dumping ~10 kW as heat in the motor and PEM cooling systems. I haven't seen it myself - you need a long steep hill below you with a full battery to get into it, and so the exact numbers I made up, but it works like that. People saw it isn't as powerful as normal L regen.)
 

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There should be two parts to the range projection equation, 1) amount of energy stored in the battery, and 2) rate of energy consumption (energy used per mile driven). I'm pretty confident that the amount of energy that can be pushed into the battery through regen is capped. So the higher range projection numbers may be heavily flavored be the low energy consumption rates as you descend long grades.

VIN # B0985
Yeah, that's gotta be right.
 

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Saghost,

Thanks...I would never have guessed the means. The 17kWH for sustained regen I used came from someeone using a dashdaq in L...does that sound right? Wish GM would publish more details.
 
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