Dsinned wrote:
Looks like a neat gadget Tony. Are you planning to share you knowledge on how to make such a thing with the forum members here, or is this something you plan to sell on Ebay or something commerically? Will it be easy to install?
The first one pictured, "LEAFscan", will be available soon at
http://www.EVSEupgrade.com, however it has not been adapted (yet) to the Rav4.
There are several models and one kit on the market for a "Gidmeter" (the second picture in the post above). They all just plug into the OBD2 port, and you can put it anywhere you want. The port on Rav4, unfortunately, is in the left rear corner of the car. So, we either need to route one twisted pair from there to the dash area, or find the signal for pin 6 and 14 somewhere in that area to tap into. Since I plan to run a dedicated 12v to the trailer lights which will also power the fuel filler door light, I'll run a twisted pair with it.
The meter will show the usable energy in a percent, which will be particularly helpful in the Rav4 with no "fuel gauge" indications for anything above 80%.
Yes, we share all knowledge. We even encourage folks who are tech savvy to help us find and identify signals. What we do is download all the data streams (with a current Gidmeter), then using a program written specifically to do this called "CANDO", we try to match up the hundreds of signals to the various pieces of information.
Obviously, one of those bits of info that we want first is the Tesla report of battery capacity (which we may have already found). That will be the basis for our fuel gauge. In the Nissan LEAF, that information is based on an inductive coulomb counter, and reported in 80 watt/hour units. Therefore, a 24kWh LEAF battery would show 24k/80 = 300 "Gids".
Like the Rav4, it doesn't use all that 24kWh capacity, so at 100% charging, the LEAF shows 281 Gids multiplied by 80 = 22.48kWh stored. Therefore, we make 281 = 100% on the Gidmeter. Turtle mode comes on at about 3%, and the relay opens at 2% to disconnect the battery (dead on the road). So, the real formula for usable percent should be 281 Gids - 8 Gids at the bottom = 273 usable Gids.
There is energy expended to pull that energy out of the battery that will make the the total usable in a LEAF at 21kWh for a new condition, 70F or greater temperature battery. As the battery degrades, or is cold, the usable energy will be less, and reflected in the Gidmeter.
These are many of the same things I expect with the Rav4.