12v Battery for Prius automatic 1.5 T Spirit 2008

[karen0305]

Hi,

I've been having problems with my 12v Battery, it went dead on me yesterday due to me having the boot open for about half an hour while I was cleaning out the car. The breakdown recovery man jump started it but said I'd need a new Battery. Does anyone know if they are a special one or can they give me a link to a reasonably priced one, as Halfords have quoted me £220, which seems expensive.

Thanks,

Karen.

[FROSTYBALLS]

£120 from a Toyota dealer - see https://www.toyota.co.uk/owners/service-mot-maintenance/repairs.json

[PeteB]

According to the Toyota web site, their fixed price service includes Battery replacement:

Battery (Petrol) £120

their web site is here:      https://www.toyota.co.uk/owners/service-mot-maintenance/repairs.json

I can't see it mentioned on the site, but you used to get a 3 year warranty with the new Battery,

Some have found cheaper ones, but you need to get the right size and type, as it lives in the boot and you don't want gasses from it in the car.  Some people have made some minor modification to the battery they bought to get a vent pipe to fit it.

For my money, I'd prefer to stick with my dealer (mine in Norwich is particularly reliable).  Looked after they can last well - on a 2002 first generation Prius I owned for 9 years, the 12v battery was still ok when I sold it.

[PeteB]

Ah, Frosty beat me to it while I was typing!

[karen0305]

Thanks all, I rang them today but no-one could help me, I'll ring them in the morning. I thought they would be more expensive at the dealers to be honest. 

Pete - my 12v Battery isn't in the boot as far as I know as the breakdown guy stuck the jump leads on one under the bonnet at the right hand side.

[PeteB]

3 minutes ago, karen0305 said:

... my 12v battery isn't in the boot...

It's under the boot floor, right side as viewed from behind.

Since the boot opener is electric and wouldn't work with a flat Battery, there are jump start terminals under the bonnet on the Mk 2 & 3 Prius.

Only the Mk 4 has the 12V Battery under the bonnet. 

[karen0305]

Oh I see. Thanks for that Peter. I've only had my Prius for a year, never even had a Toyota before, but I do really like the car, I just don't know anything about the mechanics of it. 

[Rav4ster]

Hi Karen, done my last year at Toyota dealer.
Fixed price includes installation (plastic tray needs to come out) and three years warranty.
Took an hour to do and they washed the car as well

 

[PeteB]

Hi Karen.  Will be interested to hear what you decide and how you get on.  Regards, Pete

[karen0305]

Thanks for that Andy, sounds brilliant... my car needs a wash as well!

Pete - When I decide I'll comment and let you know. The Battery seems fine at the moment, so I'm hanging fire for now but will go to Toyota if it lets me down again.

[PeteB]

1 hour ago, karen0305 said:

...Pete - When I decide I'll comment and let you know. The battery seems fine at the moment, so I'm hanging fire for now but will go to Toyota if it lets me down again.

Thanks, Karen.

Just in case you're not aware, the 12V Battery is a slight weakness in Toyota Hybrids.  Since it doesn't have to start the car (the big HV Battery does that), Toyota put a low capacity (and lighter) Battery in.  However, it does mean it's sensitive to leaving lights on, or sitting with ignition on but not 'READY'.  (When in 'READY' state, the HV battery charges the 12V battery, even when the engine is not running).  Also, when you open a door, the 12V battery runs an electric motor to pressurise the brakes, which drains it a bit more, as does the alarm and remote door lock sensors.

If you don't start a Hybrid for a few weeks, on a long holiday for example, (4-5 weeks on a Gen 1 or 2 Prius) the battery can flatten even if nothing is left on.  If the battery is weak, it can flatten more quickly.

You may find it needs replacing before next winter, even if it's fine for the summer.  But as you say, just need to keep an eye on it.

You can help by turning off the boot light by the switch on the light, and turning off the interior lights during the summer as you're not likely to need them much.  

[karen0305]

Thanks for the info Pete. Before it went flat I had the boot and back car doors open for about 40 minutes. The light in the boot must have been on, I didn't know you could turn it off actually, so I will do now. I had an operation a month ago and couldn't drive for a week though and it started straight away when I drove it after that.

My plan is to get a new Battery for the winter actually (providing it lasts that long). I will be extra careful and take your advice above for now :-)

[barrycoll]

Karen, the reason that the AA chap jumps started the car from under the bonnet, is that there are specific extra terminals conveniently situated there, to allow for this, and stop you having to struggle in the boot space.

It is worth knowing just where they are, for future reference

[karen0305]

Thanks Barry,

Pete did tell me that earlier in the thread. I was sure I could see a Battery that the guy put the jump leads on though, shows how much I know about car parts 

[cybervic]

Hi Karen, My prius recently had a 12v Battery, I bought an Varta Blue B33 Battery online (recommended by Prius taxi drivers) for £45 and fitted it myself, you can get a trusted local mechanic to fit it for you around £20-£30. It has 5 years warranty as apposed to toyota's 3 years and slightly bigger capacity because I uses dash cam and 2 in-car phone chargers.

 

The Battery never give me any trouble but when I found that voltage remains constant low at 9.5v from hidden menu on the display, I couldn't stop worry about it. After the battery replacement, fuel efficiency when from 42mpg to almost 50mpg. so the earlier you have it changed the earlier you start to save fuel money really. 

[karen0305]

Hi Vicky, thanks for the info, I've just checked out these batteries and the reviews are great. Mine does around 50mpg now but any more would be good, and it's worth it for the extra warranty. I'll definitely think about it. Thanks again.

[Yorkshire Lad]

Karen and others... in the later models - around 2018,onwards the 12 volt Battery is definitely under the bonnet on the right hand side looking from the front.  I've just been in there trying to work out why it went flat overnight.. I had a similar experience on the previous Prius - no obvious cause although the dealer tried to pretend that the that the interior light had been left on.  It hadn't, but Honest John see Saturday's Daily Telegraph - said that he and other had experienced  faulty interior light switches, and advised making very sure that they were fully 

Ian

Edited July 7, 2020 by Yorkshire Lad
New data - 2016 year cars have battery under the bonnet

[Catlover]

Those Prius with the Battery in the boot, just be aware what type of Battery is standard. Apart from batteries giving off fumes, which Toyota sort by venting the Battery via a tube through floor, there is also another serious consideration.  With the battery being in the cab area of the car, if in a crash that bursts a battery open which is a standard acid battery, it is likely the acid will be thrown around the cab area causing serious injury to passengers/driver. The battery Toyota fit at factory is an AGM type, which stands for Absorbent Glass Mat. This type of battery was developed 40 years ago for military aircraft (in case they crashed I suppose).