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Discussion in 'Video' started by fiksegts, Oct 15, 2015.
So basically no difference with max power in ready mode which is pretty much what we were expecting.
Perhaps this mode is useful if you're in a really cold climate and you need to bring the temp up faster than normal driving around would.
Not much difference at all.
The 0-60 in 3.08 was good to see though.
The difference you will see in in situations where you want the power from a cold start. Like if you could do a 0-60 out of your garage or if Brooks was doing this testing on the road outside his house.
I don't know what the power consumption is if you let it sit and warm, although it would be an interesting test, but it will certainly be less than driving to warm it up. Once it is warm enough if you hit the option it will be Ready right away. I've used this in a couple 0-60 tests to see if I would really get optimal performance and it was ready immediately after hitting the button because I had done several launches and drove for a while
I couldn't find any references to it in the manual though.
It's been suggested that Max battery Performance primarily improves the 1/4 mile times, and not 0-60. It would be interesting to see if there is any difference in that area for the P85D.
Yeah, I saw this on my P85D and was going to try and see if it made any difference. I've been figuring it wouldn't. I'm thinking, like others, that it may be more for prepping the pack for max power if it's cold soaked.
I'm probably just going to leave it alone, personally. Doesn't make any sense for me to use it as I keep my cars is a garage that doesn't really get below the 50s F.
It's not just about a cold soaked battery, but just a battery that isn't at optimal temperature. From the data we have, the option is for heating the battery to a temperature for optimal performance, and even in warm and sunny CA on a warm day ~80F, it will take a while to hit optimal temperature. Once you launch at optimal temperature several times the cooling will kick in pretty heavily.
So AFAICT from the tests I've done, you will have less than 100% performance, but still in the high 90% performance without the option on, but if you want 100% performance you can either turn it on, or wait for the temperature to rise naturally.
Warmer cells of this chemistry will always put out a little more power than colder cells at the same SoC, through the entire operating temperature range with almost linear gains. Definitely diminishing returns though, since it's not a significant gain by any means. The problem is, doing this accelerates other chemical reactions in the cells, especially at high SoC. A hot battery at near 100% SoC is probably the worst thing you can do to the batteries as far as degradation goes. That's what I was getting at. So I'd rather let my battery stay at a low temp and warm as it gets to lower SoC levels to keep the pack healthy.
It was 58 degrees in my garage this morning and at 90% I still put out 413KW within 2 minutes of starting out which was the first time I gunned it.
It's clear that at least under these circumstances the 1300 amp fuse is the limit and not the battery's ability to to draw current even when cold. This may change with the 1500 amp fuse and it may be necessary to get the batteries good and warm to reach that fuse's limit but as it stands now, this feature doesn't really seem to do anything all.
Maybe if the pack were close to freezing then it would be another story.
Quick correction. The amperage limit generally won't matter with temperature. It's that the internal resistance drops a little with heat, so A*V = W will yield slightly higher watt output due to the slightly less sagged voltage while the cells are warm. You could still pull 1300/1500A regardless, but the power will be a little different based on temperature.
I honestly am not even sure this increase in power output will be measurable in the performance vs a room temperature pack, though.
In that case, I wonder if the max power mode even makes a difference for the the P90DL at temperatures varying from that of my garage this morning to fully warm. Has anyone with a P90DL logged the max power at SOC X where X is the same for cold in the morning vs max power saying it's ready?
I thought that it had already been established that max power mode made no difference in the P90D's performance figures.
If it did, well then surely by now someone would have run at least something close to a 10.9 second quarter mile.
If we couldn't say before, that max battery power mode, made no difference, well then we ought to be able to say it now.
The numbers I logged before were with it on. It was 455 without and 457 with. The 455 was max after several runs, and when I had enabled the mode to get 457 the fans turned on after that run. So as I've mentioned it's just about getting the heat up, which can be done by just launching several times or driving hard. The difference being that launching is going to pull way more power than turning on the heater. If I hadn't launched several times to get the heat up, the first max would have been lower I'm sure.
Honestly at this point it seems like a fairly pointless feature unless there is something we don't know or it is going to turn on some other magic in the future.
You're in a warm area though, if it's just battery heating that would explain it.
Just tried Max Power Mode on P85D few days ago, feels quicker. Perhaps is much cooler in Seattle