Online Forum for the 2012 Rav4 EV

Using the GOM to estimate anything is meaningless unless you have the computer reset the mi/kWh used for display. Then you can use it to compare the usable capacity from one time to another. The simplest way to reset the mi/kWh is to disconnect the 12V battery. However, the usable energy reported by the BMS also varies with temperature and time since charging if it is balancing the battery.

As the battery degrades, the Extended Charge energy will gradually reduce until it doesn't add any energy to the battery beyond the Standard Charge. This is because Toyota wanted the Standard charge to represent a constant amount of energy. As the battery ages and degrades, the Standard Charge will charge up to a gradually increasing percentage of usable energy in the battery pack. Once the Standard Charge reaches 100% of the usable energy, the Extended Charge setting won't do anything.

Long story short, it's very unlikely that the battery would degrade 20% in the first three years and then not at all in the following three years. It's more likely that your understanding of the actual battery degradation over time was inaccurate.

Yes lithium degrades on a curve. Fast at first and then it slows down. This includes several factors including usage, time, heat, average charge level and probably more. The fact that the curve has flattened is actually expected. This is a battery, not brake shoes.

I really expect the 5 miles gained is based on your current driving style, general driving conditions and temperature as the primary factors. The 5 miles gained does not reflect actual battery capacity change. DTE meter changes based on conditions and is an estimate of range only not a battery capacity meter as then it would read energy units not miles.

Thanks all for the info on battery degradation. This my understanding of the several responses:

I shouldn't complain that my 7 year old 60K mile EV still gets 65-75 GOM (& actual) range. I rarely drive more than 25 miles a day, so who cares what the GOM says.

Like taking my blood pressure, I can "feel" when I using a lot of juice (85mph+ freeway, love the Sport button!) and my internal GOM adjusts the range pretty accurately.

I don't know how the first 35k miles were charged/driven; I drive hard, short runs.

While a declining capacity curve is the norm, the 3 year curve & followed 3 year flat line is uncommon, regardless of prior & current use & driving style.

Most likely my charging system is fine.

As the motor whine gets louder, I'll bring the car in for replacement (under warranty) and hopefully get a Techstream or Tesla diagnostic readout having some battery capacity info.

Thanks again to all. I think we can put this thread "to bed". Really appreciate all the responses & info.

Mark

You can know, for example,


Do you have a record of sound of motor whine?

No recording.

Seems I would have to put the car on a lift and get some recording equipment.
Or I would hang out the door and hold the cell phone under while moving (sounds scary).

Any info on how to get a recording of the motor noise would be appreciated.

Mark

For example (without a sound finders),
https://youtu.be/dEYsYZo8Oz8

Unrelated to your original post, but thought it a fun coincidence that yours came off the line right before mine did (VIN 1655).

1655: ... (VIN n/a)
1654: Production Date: 04/08/2013, Date of First Use: 10/22/2013, Exterior Color: 08V5, SHORELINE BLUE PEARL