What are the things i should do if i didn't start engine for around 6 months?

The battery might be dead...you'll know when you attempt to power it on. ;-)

 

Nothing I can think of...but I'll let some more experienced Hybrid drivers/tinkerers answer that definitively.

 

I am not sure about the HV battery being flat after 6 months - it might well be. But if the 12v is flat you must be very careful how you jump start the car! You are probably best taking the 12v off the car and charging it that way or maybe even replacing it if it has been allowed to fully discharge - they're not that expensive.

If the 12v is OK and the HV battery is flat (they do slowly lose charge over time without use) then I think you need special equipment to charge it back if the car is unable to do it.

 

I was referring to the 12v battery, yes. Trickle-charging that battery (if the vehicle doesn't start) surely shouldn't cause anything untoward to happen.

 

if the 12v sat for 6 months i would just buy a new one. the HV battery should be fine.

 

Unless the car was shut down with a very low HV battery (unlikely) then it is fine. the self discarge rate is something like 2% a month. If the car was shut down with 2 bars on the battery, it had about 45% charge. 9 months later it would have ~27% charge. This is low enough that the car will be angry, and will want to spend a while charging when started up (and will take a while to get to six bars), but it will certainly run.

If it went into storage with 6 bars on screen it had about 65% charge, and now has about 47%. that is completely within the entirely normal range and the car will operate normally immediately.

 

If the car really sat unused for 6 months, I would change oil and filter. Also, I would check tire air pressure. As far as the rest of the car, I think it should be fine. I think the hybrid batteries would be okay. The gasoline might need to be replaced if it's been in the tank for 6 months.

You might drive the car as if it were brand new; easy accelerations, no excessive high speeds for long periods. Maybe a new car break-in for a couple thousand miles.

 

And use 0w20 oil in a gen3/2010 Prius

 

Check fluid levels, engine oil, coolant (two systems), and brake fluid. Check tire pressures and fill washer bottle.

Put in some gas (gas may have been drained prior to shipping) and try to start it. 12V battery will probably be dead so you can either jump it or put a charger on it for a while.

Go for a long drive.

After it is completely warmed up and has run for a while I would suggest changing oil and filter. If it has over 20K miles you should consider changing transaxle fluid also. As previously mentioned most of us use 0W20 engine oil but if you can't find it 5W20 or 5W30 should be fine; transaxle must have Toyota ATF type WS (no substitutes).

 

If they did it right ALL fluids will be drained. I recently had to send a piece of rebar processing equipment to Colombia and it had to be dry.

So check ALL fluids: coolant, brake, steering, transaxle, oil, washer etc... before driving. Car companies might have waivers for this but individuals might not...best to be safe and check.

 

if battery is charged the rest should be fine.. just disconnect charger before start..

On old cars which were sitting for much longer you have to worry about bore rust/old gas/carb cleaning.. but 6mo only plus EFI shouldn't be issue.

If you planning to store car for prolong time adding gas stabilizer and putting battery on trickle is all you need..

 

Go very easy on the brakes for the first drive too: the disks will likely have built up rust.