Is the 12v battery or hybrid battery problem

[spidey]

Hi, 

I have a first gen Prius running well except for the last two months when I've had four occasions of flat Battery. No doubt the constant snow and COVID travel restrictions have contributed.

The last two times, the remote key wouldn't work and had to get the proper key to even open the car and raise the hood.

I've been told there isn't an alternator in my Prius. Does that mean it could be just a Battery replacement needed ( although the breakdown guy said the Battery was not bad ) or is there a possibility of the hybrid battery being a problem :(. Are the symptoms indicative of a hybrid battery problem ? 

I am trying to avoid paying the £120 for a routine check at the Toyota Garage. Any help welcome. Thanks.

[Catlover]

Go to a (12v) Battery specialist and ask for your Battery to be checked. If it is a 12v Battery problem then if you buy a relacement off them I would not expect to pay for the check up.

Its true, you dont have an alternator. The 12v battery is charged up from the Hybrid battery.

How old is your 12v battery??? If its more then 4 years old it could be wonky. The older it is the more sure that statement is. You in a very cold area. Even down here in Cheshire the 12v battery in mine and the wifes hybrids have been it by the cold although recovered, but mt battery is just over 4 year old and the wifes battery not yet 3 year old. Get yours checked. If your battery is in the boot it maybe an AGM battery which are usually more expensive then a fully wet acid battery. Toyota charge about £125 for an AGM battery, which is about the best price to be found. OK, just seen in your post and seen "you raised the hood" - if the battery there you probably have a wet battery (normal), dont skrimp on the power of the battery, get what Toyota recomend as a minimum, I will guess at £75 max. You cant beat a good battery.

[john p williams]

Can the Prius be put into a READY STATE twice weekly to power the 12v Battery from the Hybrid system as my Lexus can ?

[Duffryn]

Flattening the Battery (multiple times) will affect it's longevity too.

[john p williams]

Just now, Duffryn said:

Flattening the battery (multiple times) will affect it's longevity too.

Why will it flatten the Battery ?

[spidey]

Thanks Catlover, 

Hoping for the 12v Battery. Halfords check said it wasn't bad. The hood was raised to charge the flat Battery although it's in the boot. 

Just a bit anxious that it isn't anything like the hybrid Battery !

[flash22]

It's the Battery, a charge off the car can take up to 48 hours  as it needs a low and slow charge - buy the correct Battery for the car, it's an AGM type  if it's in the boot

 

Gen one Prius, its done well if it's on its original 12V Battery it maybe on its second tho - Average life is 7-12 years

Yes, the problems you are having is related to the 12V battery without it, you can not start the car, treat the Traction battery as its own system

@Catlover you can access the POS and NEG terminals under the bonnet save having to climb through the car

[Catlover]

13 minutes ago, flash22 said:

 

@Catlover you can access the POS and NEG terminals under the bonnet save having to climb through the car

I not conversant with Gen1 (nor Gen2) so I don’t know where the Battery is, that’s why I said “if the Battery there”, that is under the hood. As it is confirmed it’s in the boot then I agree it’s an AGM and possibly around the £125 mark. But a good Battery is a must.

[spidey]

Thanks Guys! Thanks for the help. Will sort it out tomorrow ! 🙂

[TonyHSD]

You can check if all is good by yourself with simple multimeter. Measure Battery before start the car should be above 12V, then start the car and measure again while car in ready mode, does not matter if engine is running or not, voltage should be 14V and above up to 14.9V wait around 30-40 , turn off the car and measure Battery again, should be slightly better figures than before you start, keep measuring for about 2-3 minutes and watch the voltage dropping and stop make a note at what exactly voltage stops and does it hold stable. If stops let say at 12.5V and doesn’t go down further your Battery is good. This is what I have done yesterday, here the last post you can compare figures for reference. 

https://www.amazon.co.uk/Multimeter-Resistance-Transistor-Continuity-Electrical-Black-Yellow/dp/B07BMQ578Z/ref=sr_1_1_sspa?crid=3PHYBD8ASAR9G&dchild=1&keywords=multimeter&qid=1613067732&sprefix=Multim%2Caps%2C669&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExRDVQME5TNUtUOUZZJmVuY3J5cHRlZElkPUEwOTE2Mjg5MTk0SEQyQjE3QUNKSiZlbmNyeXB0ZWRBZElkPUEwMjMzNjQ3MUpVTkUwRTUwOERPNCZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

[PeteB]

5 hours ago, john p williams said:

Can the Prius be put into a READY STATE twice weekly to power the 12v battery from the Hybrid system as my Lexus can ?

Yes.  The Gen 1 Prius had quite a severe parasitic drain.  A really strong Battery, fully charged when left, would be lucky to last much over 3 weeks without regular driving.  A half hour in READY Mode every week or so should be enough to keep it topped up as long as it's in good condition.  These very cold days this week will make matters a bit worse too.

A Gen 1 Prius I had from 2002 to 2011 still had the original 12V Battery in it when I sold it, so they can sometimes last a fair while.

Locking with the key instead of the remote will help the charge last slightly longer if, for example, the car is locked in a garage and you're not concerned about the alarm being deactivated.

Every time a 12V lead-acid Battery is allowed to go flat it is likely to degrade the plates inside and it will hold a little less charge each time this happens.  Leaving it flat for several days (or longer) may kill it completely.

[BhxTrev]

Firstly Catlover Joe, I never realised the 12v Battery was charged by the hybrid Battery & that my Prius doesn’t have an alternator.

I was cleaning my 2016 Gen4 Prius a couple of weeks ago. It started as normal but when I tried to blow the tyres up with my tyre inflator, the car went completely dead. I didn’t think it could be the Battery as my previous Prius battery was the best part of 7 years old & I sold it with the original battery.

I called the Toyota breakdown out & he immediately identified it was a flat battery! He checked it out & said the readings he was getting were showing that the battery was only 55% efficient & needed replacing. Like most people, I’m not using my car much at the moment but I never risk anything with any car I’ve ever had. I believe if it needs fixing it has to be done ASAP, preferably by as in this car’s case by a Toyota garage. However, on this occasion since my garage is now 40 miles away, I nipped to our local Halfords who verified the battery needed changing & it was all sorted within an hour.

The guy fitting the battery said I was lucky the battery lasted over 4 years but reassured me I had a 5 year guarantee with the one he sold me. I have to say this is the only time I’ve called out Toyotas breakdown service in all the times I’ve ever owned a Toyota & it actually rates as just about the only problem I’ve ever had with both of my Prius cars. Not bad going really.

[BobR]

Just for info.  I had exactly the same problem with a nearly 4 year old Prius just two weeks ago.  It was replaced by the local dealer under the Toyota 5 year warranty FOC- no issue, which was great and very much to my surprise.  I had assumed at least it would be a pro rata replacement based on its age.

The replacement was a Toyota Battery -  28800-YZZZE which is a higher capacity than the original, 52Ah.  It is maintenance free so I think it may be an AGM type.

[Harters]

I was pleased that mine went through its 4 year service last weekend with no mention of any problems with the 12v Battery.

Not using my car much at all at the moment, so I am hooking it up to a smart charger which is obviously doing its job 😀

[PeteB]

I had an email from my dealer a few days ago with details (but not prices) of a couple of smart charges they are now offering.  It invited me to call them to discuss.

[BhxTrev]

Hi Pete, that’s interesting. Please let me know what these ‘smart charges’ are & any pricing. I guess I was a bit swift changing my Battery especially as it was the first time it had let me down & I’d hardly used the car for weeks, due to the lockdown. However, I wasn’t going to risk anything & I got a new Battery straight away. I’ve also got the peace of mind that it’s guaranteed for 5 years which I’m quite happy about!

[PeteB]

Hi Trevor.  They don't mention specific brands or prices, and I've not made any enquiries.  This is the relevant page of the email:

I do keep a mini jump starter in the car, which is discussed here:  https://www.toyotaownersclub.com/forums/topic/190773-low-voltage-12v-battery-failure-gen4-some-advice-please/?do=findComment&comment=1516994

I've also used it a couple of times to help out people with 'ordinary' petrol cars and they've been astonished something so small starter their car.

The brand I have isn't listed by Amazon any more, but in case it's of interest, they have this one:  https://www.amazon.co.uk/BIUBLE-Battery-Starter-12800mAh-Charge/dp/B08X4XGR68/ref=sr_1_1_sspa?crid=1JMFSDFAG9F9U&dchild=1&keywords=ravpower+jump+starter&qid=1614175144&sprefix=RAVPower+Jump+Starter%2Caps%2C203&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExMERVQThGQ0VGV0xVJmVuY3J5cHRlZElkPUEwMjQwODA1MjlPVzlBT0dPTFpLJmVuY3J5cHRlZEFkSWQ9QTAxOTkyNjBQWUgxVjY1Mjc5Wkwmd2lkZ2V0TmFtZT1zcF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl

 

 

[john p williams]

I have the BIUBLE too and it`s great !

[Harters]

This is the smart charger I have and its working well for me, great price too.

https://www.amazon.co.uk/gp/product/B009A83P1E/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[john p williams]

34 minutes ago, Harters said:

This is the smart charger I have and its working food for me, great price too.

https://www.amazon.co.uk/gp/product/B009A83P1E/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

If it works satisfactorily then at that price, every vehicle owner should have one.