dgpcolorado wrote:I'm puzzled by what you mean by "precise SOC" and how it differs from GID% or Ah%. [I just assumed that the %SOC display on the 2013 LEAF is a GID%, is that not the case?]
Regardless, any of the usual measures discussed plus your current in/out display and battery temperatures would be of great interest to me. I am especially curious to see how the temperature changes as I climb and descend hills, a routine part of my driving. (The utility of the voltage display I don't really understand, need to think about that some more...)
I like it!
Thanks! Having the temperature info has sure been enlightening to me in the last few weeks.. For example, parking in the sun for a few hours isn't as bad as parking on hot pavement.. The car absorbs more heat from the ground beneath it than the hot cabin above it..
I haven't played with the SOC on the new 2013s but I have seen photos of 100% at "full".. I presume it's 0% when the car stops? Or at low power turtle mode?
It turns out that active polling of the CAN bus (ie asking for info rather than just listening to the other controllers talk to each other) can get a precise (XX.XXXX%) SOC reading just like the passive 0x55b message discovered a while back but with much more precision (3 more decimal places worth!.. although I'm only displaying 2 decimal places, the less significant digits move too rapidly to be useful.. You can still see the full precision on page 2 of the display if you wish).
So the raw precision SOC will be a number that (regardless of your car's battery capacity) will charge up to about 94.50% to 96.20% (in most cases). Incidentally you will find days with higher GID counts that also had the car charging to a higher SOC... ie some days 272 Gids @ 94.6% and some days at 274 Gids at 95.4% (for a reasonably healthy car with about 64Ah capacity..)
As others have pointed out the only true marker for LBW and VLBW is Gids.. When you go from 50 to 49 that's Low Battery.. When you go from 25 to 24 that's Very Low Battery. As for turtle and absolute dead stop that's harder to say.. usually around 4-8Gids. It probably has more to do with absolute cell voltages than anything. Page 3 on the LeafDD shows all the cell voltages as well as minimums and maximums..
Gid% (Gid*.356) is just provided for those who prefer to see Gids converted to a percentage but note due to space constraints on the screen the LeafDD can't display more than 99.99% So any new cars with 282Gids still get 99.99%. I'm merely providing this option for people with older vehicles who have grown accustomed to seeing Gids this way.
I think the 4th option, Ah% or Ah capacity * precision SOC will be most interesting. It's very much like Gids in that the units are constant with respect to the capacity of your car but with more precision and less hysteresis so you can see the regen you're getting going down a hill..
A new 2012 Leaf has about a 66Ah capacity and will charge up to 278-281Gids.. Such a car would show something like 62.96 when full (66.00*95.40).
A sun baked Phoenix car might have a 52Ah capacity (maybe 220Gids full?) but still charge to the same 95%.. so on wake up they might see about 49.40.
I was hesitant to add yet another energy number to the mix but it's really just two existing numbers in the raw data multiplied together (Capacity * SOC) with no additional constants added. I'd recommend people unfamiliar with this stuff just start off with the raw Gids (easy to digest) or the precision SOC which is fun to watch but keep in mind that unlike Gids, the units will change with the capacity of your pack.. The 66Ah new car and 52Ah sun baked car will both charge up to about 95% but the latter will have proportionally fewer Gids (and Ahs).