Just had to replace the Main Battery in my 2001 Prius - Page 2

 



I would appreciate your taking your case to Toyota and asking them to
engineer a fall-back to the ICE for future models.  I'd do it myself, but
having evidence of a failed battery and having endured the consequence of
it's failure to fall-back gives you more credibility.

 


Bill wrote:

I really doubt they would do anything for the 2001 version of the
Prius, they may of already addressed the problem in the new model.

 


Not functional at all if the electrics fail; the electrics provide the
"ECVT" transmission action. It makes sense the ICE would rev freely under
those conditions. It is interesting that without the battery operating the
HV system is basically inoperable, but it's not terribly surprising.


Like most of the other battery failures I've read about (mostly in the
Yahoo! forum), this one is almost certainly a failed connection inside the
battery pack. This is the first sudden total failure I've heard about,
though.

Mike

 


Michael Pardee wrote:

To further describe it.

This is how "neutral" works.  Since the gears in the tranny/diffy are
always engaged, neutral is achieved by disconneting all power from both
electric motors.  This is why the batteries will not charge in neutral
- no power goes in or out of the MGs.  In neutral, the ICE spins but
delivers no torque to the wheels as MG1 freewheels backward.  Losing
the HV battery system will create the same condition - like putting the
selector in "N".

On the other hand, if you run out of gas, or the ICE otherwise fails,
you can "limp" around for a short time on MG2 until the batteries die.

 

   The reason that the ICE just revs up with no power being delivered when
the main battery fails, is because the delivery of power to the ring gear of
the Power-Split-Device (and to the wheels) is dependent on there being power
delivered to MG-1 to counter the torque of the ICE.  Otherwise the Sun gear
just spins and no torque is delivered to drive the car.

Dick