Turbo3 wrote:When you hit a certain gid level the car gives you a low battery warning or very low battery warning. So the amount of Gids you have left is of some importance to the car and should be to the driver.
Jim, I really appreciate all the work that has gone into WattLeft and the ELM327 project, and I don't want to open another unnecessary discussion, since I know how hard it is to get consensus here. It took a lot of effort to get an agreement on 21 kWh usable and on 24 kWh rated capacity a while back, for example. There will always be folks with some kind of bias or a personal opinion. It's just the way it is with these things. That said, Nissan has not indexed the instruments in the LEAF to some imaginary values. No, they have been calibrated to certain levels of stored energy.
Take the low battery warning, for example. It comes up at 4 kWh stored energy remaining, which is a constant and does not change over time as the battery degrades. The very low battery warning comes up at 2 kW stored energy remaining. This is not just my opinion, these design decisions are a matter of public record. Since we are essentially reverse engineering the car, it takes effort and sometimes even faith to bridge the gaps in our understanding. Gids are units of stored energy, and not SOC, as was originally assumed. They represent watt-hours and kilowatt-hours, which are universally understood as units of energy.
WattsLeaf is an excellent product, and you might not want to redesign it. That said, before the next revision of the LEAF platform and before a different battery pack is released, it would be good to agree that it's beneficial to find a way to express stored energy in universal units of measure. It won't help matters if a certain group of LEAF owners was looking at raw CAN bus values, which meant one thing, and another group of owners would use something different, because their LEAF had a new battery pack and new software.
Going from an old LEAF to a new LEAF would be a big transition, since these aftermarket devices would use different raw values from the CAN bus. If kilowatt-hours were used, then the transition would be seamless. Besides, isn't one of the goals that Nissan should show kWh directly on the dash? It would be good if the strong engineering community we have here set the right tone at some point in the not-too-distant future, and demonstrated that this approach can work.