96
PRIUS PRIME_OM_OM47C77U_(U)
2-1. Plug-in hybrid system
■If the vehicle is not used for a long time
●The 12-volt battery may discharge. In this event, charge the 12 -volt battery. 
( P. 595)
In  order  to  prevent  the  hybrid  battery  (traction  battery)  from  becoming
extremely  low  in  charge,  charge  the  hybrid  battery  (traction  ba ttery)  from
external power source or start the hybrid system at least once  every 2 or 3
months,  and  turn  the  power  switch  off  after  the  gasoline  engine  has
stopped  automatically.  (If  the  gasoline  engine  does  not  start  up  even  after
approximately 10 seconds have pass ed since the “READY” indicator came
on, the power switch can be turned to off without any further action.)
● When  the  vehicle  is  left  with  the  charging  cable  connected,  the   electricity
consumption  amount  of  the  12-volt  battery  increases  due  to  cont rols,  such
as the system checking, operating. When the charging cable is n ot needed,
immediately remove it from the vehicle.
■ Sounds and vibrations sp ecific to a hybrid vehicle
There may be no engine sound or vibration even though the vehic le is able to
move with the “READY” indicator is illuminated. For safety, app ly the parking
brake and make sure to shift the shift position to P when parke d.
The  following  sounds  or  vibrations  may  occur  when  the  hybrid  sy stem  is
operating and are not a malfunction.
● Motor sounds may be heard from the engine compartment.
● Sounds  may  be  heard  from  the  hybrid  battery  (traction  battery)  when  the
hybrid system starts or stops.
● Relay operating sounds such as a snap or soft clank will be emi tted from the
hybrid battery (traction battery), behind the rear seats, when  the hybrid sys-
tem is started or stopped.
● Sounds from the hybrid system may be heard when the back door is open.
● Sounds  may  be  heard  from  the  transmission  when  the  gasoline  engine
starts or stops, when driving at low speeds, or during idling.
● Engine sounds may be heard when accelerating sharply.
● Sounds may be heard due to regenerative braking when the brake  pedal is
depressed or as the accelerator pedal is released.
● Vibration may be felt when the gasoline engine starts or stops.
● Cooling fan sounds may be heard from the air intake vent. ( P. 99)
■ Vehicle proximity notification system
In  the  following  cases,  the  vehicle  proximity  notification  syst em  may  be  diffi-
cult for surrounding people to hear.
● In very noisy areas
● In the wind or the rain
Also,  as  the  vehicle  proximity  notification  system  is  installed   on  the  front  of
the vehicle, it may be more difficult to hear from the rear of  the  vehicle  com-
pared to the front.