Will my battery drain?

[dbascher]

Just got my 2005 Prius! I travel a lot, sometimes for weeks at a time, so I was sure to ask the dealer if this would be a problem. He said the hybrid battery "was really big" and "wouldn't be a problem" even if the car wasn't started for weeks or even amonth.

But the manual states that the battery will deplete after two weeks of no driving!!

Anybody have any knowledge to share?

[V8Cobrakid]

it's probably refering to the small 12v battery the car uses for acc and starting the system. if you have the se/ss (smart entry/smart start) system, it constantly looks for your key fog.. and after a week or two it can drain the system. there is a button under the steering column to disble it.. just i case you go for a trip or something.

[efusco]

Just got my 2005 Prius! I travel a lot, sometimes for weeks at a time, so I was sure to ask the dealer if this would be a problem. He said the hybrid battery "was really big" and "wouldn't be a problem" even if the car wasn't started for weeks or even amonth.

But the manual states that the battery will deplete after two weeks of no driving!!

Anybody have any knowledge to share?

Yes, remember there are 2 batteries. The large Traction Battery (aka HV battery or NiMH battery) will tolerate sitting unused for 6 months to a year from a full charge. It should not be a concern to you at all.

The small 12v PbAcid battery is smaller than the ones used in most 'regular' cars. Add to that that if you have the SKS and it is active (ie. doors locked) it will continuously sense for you key fob which drains the battery. Some have reported as little as 7 days, others have gone over 2 weeks without incident.

If you know you will be away for more than 10 days AND you plan to leave the vehicle locked AND you have the SKS then you should disable the SKS by pushing the button under the steering column...this is covered in your owner's manual. Anything at a week or less, or if you don't have SKS, or if you don't leave the car locked you probably don't need to worry about it unless you'll be gone for more than 2 weeks.

If you will be gone for more than 2 weeks you may want to consider pulling the master fuse or having someone start the car for a few minutes once a week to allow recharging of the 12v battery.

[dbascher]

Thanks for those great replies! I hate Navigation systems, so I got the "Package 1" on the 2005 which does NOT include the Smart Key System, so I think I'll be okay.

Thanks again...and I LOVE THIS CAR!

[bruceha_2000]

I hate Navigation systems, so I got the "Package 1" on the 2005 which does NOT include the Smart Key System, so I think I'll be okay.

Oh, but you would have LOVED the SKS. :-)

[mspencer]

I thought the HV battery was NiMH.

http://www.batteryuniversity.com/partone-4.htm (near the bottom)

[efusco]

I thought the HV battery was NiMH.

http://www.batteryuniversity.com/partone-4.htm (near the bottom)

It is, that's what I said...Traction battery = HV Battery = NiMH battery...all the same thing.

[Chickie Chicksworth]

I have a 2005 Prius and was driving about 5 minutes, going uphill when the car went dead and started rolling downhill. The only explanation I can come up with is that I had the heater up as high as it can go. Anyone experience this?

[bruceha_2000]

Chickie - First, you didn't run out of gas, right?
If not, did you get the ugly exclamation point in the triangle? I think you want to take it to your Toyota service people and have them pull the codes.
I don't think the heater on full should cause ANY problem.

[efusco]

I have a 2005 Prius and was driving about 5 minutes, going uphill when the car went dead and started rolling downhill. The only explanation I can come up with is that I had the heater up as high as it can go. Anyone experience this?

Never ever heard anything of the sort, and frankly find it incredibly hard to believe. Did it go into neutral? That's the only way the car could roll backwards even if it was totally dead.

You need to give us a LOT more details...batter SOC, warnings/alerts, pre-dead behavior, did it restart? Did you take it to the dealer and have it towed or did it start right back up and run normally?

What was the fuel level? How many miles on the car and how many miles.

I can assure you that if this did occur as you described and is not due to you hitting neutral on accident or running out of gas or something like that then Toyota will be extremely interested in testing the vehicle to try to find out what went wrong as they build in multiple redundant fail safes to prevent just that kind of problem.

Also, how the heck did it start rolling down the hill...you had forward momentum, right? When the car died and started slowing didn't you pull to the side of the road and apply the brake to stop and park it? Who would just let it roll to a stop then roll back down the hill...and if you...then why?