DO-IT-YOURSELF MAINTENANCE Electrical components -> Checking 12 volt battery condition for Your Toyota Prius 4 Door Second Generation (2004-2009)

Checking 12 volt battery  
condition—  
—Precautions  
—Checking 12 volt battery  
exterior  
EMERGENCY MEASURES  
CAUTION  
If electrolyte gets in your eyes,  
flush your eyes with clean water  
and get immediate medical atten-  
tion. If possible, continue to apply  
water with a sponge or cloth while  
en route to the medical office.  
12 VOLT BATTERY PRECAUTIONS  
When the 12 volt battery must be re-  
placed, use the Prius designated bat-  
tery.  
The 12 volt battery produces flam-  
mable and explosive hydrogen gas.  
If electrolyte gets on your skin,  
thoroughly wash the contact area. If  
you feel pain or burn, get medical  
attention immediately.  
Do not cause a spark from the bat-  
tery with tools.  
Do not smoke or light a match near  
the battery.  
If electrolyte gets on your clothes,  
there is a possibility of its soaking  
through to your skin, so immediate-  
ly take off the exposed clothing and  
follow the procedure above, if nec-  
essary.  
Open the back door. Remove the lug-  
gage storage box and 12 volt battery  
cover.  
The electrolyte contains poisonous  
and corrosive sulfuric acid.  
Avoid contact with eyes, skin or  
clothes.  
If the back door does not open, see “If  
you cannot operate back door opener” on  
page 376.  
Never ingest electrolyte.  
If you accidentally swallow electro-  
lyte, drink a large quantity of water  
or milk. Follow with milk of magne-  
sia, beaten raw egg or vegetable  
oil. Then go immediately for emer-  
gency help.  
Wear protective safety glasses when  
working near the battery.  
Keep children away from the bat-  
tery.  
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After you reconnect the 12 volt battery,  
shift the shift lever to “N” and confirm the  
shift position is “N” when the “IGON”  
mode is enabled.  
Holddown clamp  
Ground cable  
NOTICE  
z Be sure the hybrid system and all  
accessories are off before perform-  
ing maintenance.  
After connecting the cables, the hybrid  
system may not start by pushing the  
“POWER” switch. In that case, push it  
once again.  
z When checking the battery, remove  
the ground cable from the negative  
terminal (“–” mark) first and rein-  
stall it last.  
z Be careful not to cause a short cir-  
cuit with tools.  
Terminals  
z Take care no solution gets into the  
battery when washing it.  
Check the battery for corroded or loose  
terminal connections, cracks, or loose  
hold−down clamp.  
If the 12 volt battery is disconnected or  
run down, the power window and back  
door may not operate automatically and  
the jam protection function will not func-  
tion correctly and does not open the back  
door after you reconnect, replace or re-  
charge the battery. In any of these cases,  
you should normalize each system. To  
normalize them, see “Power windows” on  
page 43 and “Back door” on page 42.  
a. If the battery is corroded, wash it off  
with a solution of warm water and bak-  
ing soda. Coat the outside of the termi-  
nals with grease to prevent further cor-  
rosion.  
b. If the terminal connections are loose,  
tighten their clamp nuts—but do not  
overtighten.  
Before you disconnect the 12 volt battery,  
confirm the shift position is “P” and apply  
the parking brake completely.  
c. Tighten the holddown clamp only  
enough to keep the battery firmly in  
place. Overtightening may damage the  
battery case.  
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