Battery Confused?

Looks pretty normal to me.

 

OK, think of a toilet with the ball slightly misadjusted.*



As it fills all is fine and it comes to a stop RIGHT at the top of the overflow tube and shuts off. Then a tiny bit over water goes down the tube and it restarts filling. Over and over.

The Prius computers treat your HV battery the same way. All is well while you fill the battery until it get to the point the computers are happy it is full. (For my Prius, this varies by day, it wants to be fuller when cold) Now that it is full, the Prius tries to use some power and immediately decides it needs re-filling. Over and over again.

This is normal, and means your computers are happy with the battery level.

*I am certain there is a classier analogy, but I don't know what it is.

 

I would add an explanation of what appears to be a normal condition,
the flickering of the yellow electrical power flow arrows, from a
different perspective.

First, some things to remember:
* the Hybrid Synergy Drive's (HSD) operating algorithms are
maximized for minimum pollution and then minimum fuel usage.
* the accelerator, the "go-pedal," transmits requests for torque to the
HSD. Torque at the wheels results in speed across the ground.
* the electrical power flow display is only an approximation of what's
really happening. The clearest example of this is that there are really
two motor-generators (MG) not the single one shown. The interplay
between the two is quite complex and is not shown.

The HSD is constantly doing a balancing act between most efficient
operation of the internal combustion engine (ICE) and requests for
torque that are outside it's limits for efficiency. For small ICE torque
excesses, the HSD uses the power split device (PSD) to send excess
torque through MG1 via the PSD, now converted to electricity and onto
the HV battery. If there is a small torque deficit, the HSD adds torque
by way of electrical power from the HV battery via the MGs.

From an efficiency point of view, it would be best to drive with no
power being dumped to or taken from the HV battery; no yellow arrows
and no mechanical->electrical->chemical->elec->mech conversion
losses. This condition is hard to get, and harder to sustain. There are
numerous really small changes in conditions that play havoc with the
HSD's providing the exact torque to the wheels that is asked for: wind
speed and direction, road undulations, small go-pedal position changes,
to name a few.

The bottom line is that the dancing yellow arrows are the HSD
balancing ICE and HV battery power inputs to meet your instantaneous
torque request. The HSD's found an ICE output that's really close, but
it's tweaking ICE/HV battery inputs for max efficiency and min
pollution.

What's not to like?

 

Are you passively aggressively calling the Prius a piece of crap with this toilet analogy?

 

Normal.

 

Hey, at least it was a toilet tank analogy not the toilet bowl.