HV discharged while driving.

good question. and how to determine if the battery is changing, or if the computer decided the engine wasn't up to snuff and used more battery for some reason?

 

Sounds kind of like the recalibration behaviour of Honda's IMA system, which the car's computer invokes when it doesn't trust it's perception of battery charge percent. The computer vicariously keeps track of how much charge has been deposited and withdrawn, bases it's perception on this. With an ailing battery it'll find the "books" not balancing, and reacts by first showing charge as minimum, then going through a forced charge regimen, and finally declaring the best it can do as "fully charged".

 

I mostly try to drive similar to the "battery-sparing" way you describe. My battery state-of-charge indicator shows exactly 6 segments most of the time, never 8 except after major descents. Occasionally it inexplicably drops to 2, much as you described, then may not do that again for several months. Those drops typically seem to occur when I'm in an unfamiliar area, distracted, and not observing usual habits.

 

The main time I'll see 2 bars is on very flat roads at lower speeds, and extended crawl pace driving, say around a parking lot, or in a traffic jam.

 

Ours will still fill up all the bars, given a steep/long enough hill. It's had the inverter recall.

 

The traction battery delivers about 200V. The cars inverter can make out of those 200V, 600V. For me this usually happens when driving slow and delicate like you. If the petrol engine is still working (warming up) and you are going slow the inverter sometimes kicks in with the 600V lowering petrol consumption but understandably increasing battery usage. Thanks to that your battery charge will drop really quick, usually to 2 bars.

 

This "boost" does not happen only when warming up. To get this boost you only need to be going bellow 40 miles/h and have your petrol engine working for any reason.