Toyota hybrid 12v battery draining constantly.

yagan

Hi, we're an elderly relatively who has owned toyotas/lexus without issue for almost four decades but a few years ago she bought her first hybrid corolla.

She doesn't drive much, ten minute trips to the shop/church every second day mostly, so initially when the car wouldn't start I assumed it was because she might not have locked it properly and the battery drained searching for her fob key.

She was badly let down recently when it went flat again and so I did a bit reading up to see if this was a common issue. I didn't realise that along with the hybrid battery there's also a 12v starter battery. It just seems very convoluted and unnecessary, and most importantly it has completely undermined her decades old confidence in the brand.

She's driven toyota/lexus cars for decades without such an issue so I think it's entirely fair to expect the newest versions to not be so flawed.

We're currently helping her pick something else suitable for her needs that just has a straight forward one battery set up, but she's sworn off the brand and it has put us off ever switching to it ourselves.

But I surprised I haven't heard about it much in Irish media just as a consumer issue. Surely it's a reasonable expectation to buy a new toyota without having to worry about this issue.

Have I missed coverage of this specific issue in Irish media?

DublinDilbert

The car has a fault, nothing wrong with the toyota hybrid design, it is tried and tested. I've owned 2 of them, and know lots of people with them.

12v battery just needs to unlock the doors and allow the main contractors to close, doesn't start the car. Not complex at all.

If the 12v battery is flat, the battery is bad or something is draining it (more than likely). Any after market electronics in the car?

elperello

The car doesn't need to be replaced the fault needs to be diagnosed and rectified.

It's under guarantee so the dealer will fix it free of charge.

As the other poster says those cars have a reputation for reliability.

freddieot

Nothing wrong with the brand. Probably a Monday battery. Just get a new battery on warranty from the dealer.

FintanMcluskey

Toyota is the most reliable brand on the road.

As above something needs to be rectified, Toyota are usually excellent for back up

denismc

It wouldn't be unusual for the 12v battery to go in a car that's a few years old, especially one that is being driven infrequently.

The battery is not getting charged enough from infrequent driving, so they need a new battery or the battery needs to go on a trickle charger for a few days.

There's probably nothing wrong with the car.

Daveq

My wife's aunt has a 232 Yaris Cross. She had the same issue. The first time was within about 3 months of ownership, there was a bit of back and forth but after going back to Toyota the third time they admitted there was a fault and replaced the 12V battery, she thinks they said they did something else too but doesn't know what. Problem never came back, and that's close to a year now.

I'd be bringing it back to them.

Rows Grower

It could be as simple as your aunt has a habit of leaving her keys in the door panel of the car without locking it when she goes to mass or the shop. I know one friend had a habit of doing that and it would drain the 12V battery.

blue5000

Having similar issues with a 2.0L diesel 2016 rav4. It cranks the engine but won't start. Over 200k kms on the car now, wife is well fed up of it. It's like as if the car immobiliser or fuel pump is faulty. Tried a new battery and it was ok for a few days, won't even start with a jump start now. Anyone got any suggestions? Have tried swapping around the ignition/lights/fuel pump relays, but no joy.

It has the stop start system for traffic lights, but we turn that off for fear of being stranded in the middle of a busy junction.

hoodie6029

So your elderly relative will eat thousands of euro in depreciation for the sake of a new battery and possibly a couple of hours in a garage for investigation? Since all other types of cars being perfectly reliable, yep, this logic checks out….

‘These new-fangled hybrids, they’re only on the mass market for 25 years. They’ll never catch on’

User1998

Very strange to feel that way because of a faulty 12v battery. Just get it fixed and move on with life

yagan

https://www.boards.ie/discussion/comment/122571655#Comment_122571655

She got it serviced last year and I made sure to ask that they checked the battery, but they said there was nothing wrong.

I've seen a youtube video from a guy in England who installed a solar charger recommended by his Toyota dealership to avoid the same problem.

https://www.youtube.com/watch?v=o8MkFUPfdvQ

I can't see her wanting to put up with doing this. Anyway she found a few non hybrid options over the weekend so the corolla will be passed on soon.

hoodie6029

Is it still under warranty?

Buffman

Ye, it's not an uncommon problem on HEVs that don't get much driving.

The main problem being that they are designed/supplied with very small capacity 12V batteries as they are only designed to run the 12V ancillaries and so they can drain to unusable levels much faster if not used when compared to their ICE cousins with larger capacity 12V batteries required to start the engine.

Always on items like the alarm/immobiliser etc. are constantly draining power. It's a bit ironic when you think back to Toyota advertising all their HEVs as 'self-charging'.

You've already posted one possible solution with the solar maintainer OP, another would be sourcing the largest possible Ah capacity battery that will physically fit in the car.

yagan

https://www.boards.ie/discussion/comment/122574101#Comment_122574101

I was assuming it would be but when I talked with my local Toyota dealer they said I'd have to pay for the 12v battery replacement.

I guess they see the car being under driven as use outside it's design parameters, which makes zero sense considering it was never as issue with Toyotas in the past.

I'd imagine short distance use would be designed for in a petrol car. For example no dealer would recommend a diesel body for short distance driving.

hoodie6029

https://www.boards.ie/discussion/comment/122574780#Comment_122574780

I’d imagine the investigation of fault would be covered under warranty? Something in the electrical system of the car is causing it drain more than likely. If Toyota fitted a faulty battery from new, also their fault to fix.
It is a thing with the older generation of people that once ‘the lose confidence in a car’ nothing will change their mind about it. I can see why she wants to change even though I’d advise a less rash course of action.

yagan

https://www.boards.ie/discussion/comment/122574853#Comment_122574853

What's interesting is in the video link I posted earlier Toyota Poland recognise that there is a problem in some cars with this issue, and the battery is replaced for free, however I can imagine each national francise might be very reluctant to admit it until it becomes a common consumer complaint.

She bought that car in the belief that it may be her last drive before having to hang up the keys, and she's got a good few more years in her as her eyesight for her age is excellent. As I said she's had either a Toyota or Lexus for over three decades and she's never encountered such a problem but as her first hybrid it's been a huge let down.

My take on it is while there's still plenty of Corollas from the pre hybrid age on the road I doubt todays Corollas will be as long lasting.

Esel

^ I wonder why many other manufacturers pay to use Toyota's hybrid technology then?

The 'solution' here is a classic example of throwing the baby out with the bath water.

hoodie6029

https://www.boards.ie/discussion/comment/122575028#Comment_122575028

I remember in the early 2000’s their red colour cars suffered terrible lacquer peel and they denied responsibility until a big group of owners in the UK got together and forced them to fix it under warranty. Not surprising if this drain is a widespread issue that they’ll try to avoid it.

Their history with honouring warranty calims and recalls isn’t great.

yagan

https://www.boards.ie/discussion/comment/122575064#Comment_122575064

Even in Japan Toyota saw sales drop after the Daihatsu debacle.

yagan

https://www.boards.ie/discussion/comment/122575114#Comment_122575114

I remember seeing those red cars all over Ireland but hadn't realized that there'd been a court case in the UK over it.

Bigus

With such little use ,just stick a brand new 12v battery in it every 12 months, or less if necessary. Will cost €120 per annum if you don’t recoup some money selling the old battery. A tiny tiny fraction of replacing the car . Would be no harm to run the fuel out of it too and only 1/4 fill due to modern fuels going off quickly.

PADRAIC.M

The auxiliary battery needs to to be charged, same as all the other cars with traditional Altenator systems. Small journeys and idle time add up to the battery being discharged more than charged and the general health of the battery depleting over time, there is quite and easy was to fix this issue. Put the car into “Ready” for 1 hour every 2 weeks.

yagan

https://www.boards.ie/discussion/comment/122575628#Comment_122575628

If it were my car then maybe, but she just gone off it now most probably because she never had such a problem having Toyota/Lexus for 30 years.

Now she wants a straight no fuss single battery car that doesn't need to be driven more than she needs to drive.

Such cars do still exist.

mikeecho

I've skipped thru all the comments..

Neighbors elderly parents have the same issue with a 2021 Toyota hybrid.

The main dealers solution was to give it a good drive of 60km every week.

yagan

https://www.boards.ie/discussion/comment/122575972#Comment_122575972

They really should tell customers that their cars require such attention.

I'm really surprised more people aren't making noise about this.

elperello

https://www.boards.ie/discussion/comment/122576086#Comment_122576086

Probably because most owners drive their cars more.

How often is the Corolla in question actually driven and how much mileage per month ?

User1998

https://www.boards.ie/discussion/comment/122576086#Comment_122576086

Its a non issue for most people. Majority drive their cars for more than 30 minutes a week. And the batteries in petrol/diesel would be prone to going flat too after long periods of non use. Particularly after 5 years when the battery gets a bit older.

elperello

https://www.boards.ie/discussion/comment/122576158#Comment_122576158

I remember a relation bought a low mileage Lexus LS400.

Previous owner was an elderly lady who only drove it once a week to the shops.

The car was always garaged and had a trickle charger installed under the bonnet which she kept plugged in.

yagan

https://www.boards.ie/discussion/comment/122576148#Comment_122576148

It should be stated upfront!

Her millage was never an issue in her previous non hybrid Toyota products. They moved the goalposts and didn't tell her.

elperello

https://www.boards.ie/discussion/comment/122576308#Comment_122576308

I get your point.

Presumably the dealer knew her usage requirements.

Still someone is going to get a good car when she trades in.

What is she getting ?

yagan

https://www.boards.ie/discussion/comment/122576336#Comment_122576336

I don't know yet, my wife took her looking at the weekend.

kirving

https://www.boards.ie/discussion/comment/122574690#Comment_122574690

Does a Corrola Hybrid use an alternator even? If not, then the HV system should be charing the 12V system even when the car is off. I know the below part isn't necessarily in the Corrola, but it's a mature tech, in lots of HEV, PHEV and BEVs today.

https://www.toyota-industries.com/products/automobile/electronics/converter/index.html

https://www.boards.ie/discussion/2058367097/toyota-hybrid-12v-battery-draining-constantly

Almost all automotive electronics today use 12V. Toyota, and their suppliers don't make door locks, windows switches and windscreen wipers, etc. specifically for hybird or electric cars. The easiest, cheapest and safest thing to do is to also include a 12V battery.

Changes are coming down the tracks, slowly but surely, but there won't even be an EV on the market for 10+ years which has just a single high voltage battery.

In general, Toyota Hybrids are the most reliable cars on the road. They are the benchmark. Don't let a single bad battery fool you into thinking otherwise.

As a counter point - I had major trouble with a PHEV (moreso the labour cost than the actual issue tbh, but it had 3 batteries HV, 12V and a Stop/Start), and I now have a straight Petrol car, 3.5yrs old with a single battery.

It was doing some funny things like losing my settings on the radio, but I put it down to crappy software on a new car. I went to hardwire a dashcam recently, and found while testing it that in fact the 12V battery is very weak. The very same could happen on a car you switch to.

yagan

https://www.boards.ie/discussion/comment/122576737#Comment_122576737

It's not just a bad battery that's my predicament though.

We have a straight forward single battery petrol and I dropped into the dealership we bought it from and they confirmed that a hybrid would not suit the average driving my aunt does. He did say though she shouldn't have any low usage problems with a mild hybrid.

The whole point of this thread was to ask for other experiences for older drivers with hybrids whose weekly drive might be a ten minute round trip to the shop maybe twice a week, with an even shorter round trip to her local church, and the conclusion seems to be that that's too little for a lot of modern hybrids.

Her driving habits were the same when she owned a non hybrid lexus and she never had these problems. I do think Toyota should inform customers that there a minimum usage threshold under which the car will have issues.

denismc

It could be that the battery in her previous car was of a better quality and had more Ahs.

Manufacturers trying to cut costs are starting to skimp on batteries, we just just replaced a battery in our Hyundai after 2.5 years due to it dropping below 12V.

The new battery is 65 Ah compared to the fitted 60Ah, seems to be ok so far but time will tell.

yagan

https://www.boards.ie/discussion/comment/122577878#Comment_122577878

We dropped her car into the local Toyota dealship for a check, and they say there's nothing wrong with any of the cars batteries.

As another poster said other Toyota dealerships have at least warned that the new hybrid need a 60 min spin once a week to keep them happy. Our aunt doesn't want to liability, she wanted a Toyota that would start the few times a week she needed it.

She had no problem with pre hybrid toyotas so I feel they she should have been advised that she'd have to change her driving with the newer models just to keep them working.

Tabnabs

We have a family member with a 2021 Rav 4 with little enough usage and the 12v battery is a constant bane for them. they had to get the car jump-started recently and the call out service guy told them that it's a very regular issue with Toyota. Great car, well engineered, but the 12v battery is absolutely the Achilles heal of the Toyota hybrid set up.

yagan

https://www.boards.ie/discussion/comment/122578621#Comment_122578621

I've seen a YouTube clip this afternoon by a UK road side assist responder who demonstrated how the factory battery on Yaris's since 2019 are simply too weak.

He recommends a stronger battery like they used to install pre 2019 but Toyota won't pay for this change.

kirving

https://www.boards.ie/discussion/comment/122577788#Comment_122577788

Which non-hybrid Lexus did she have? It's likely not terribly new. You still haven't said how old this car is either, or if it's still under warranty. I'm happy to be proven wrong, but I think the car is a few years older than we're being led to believe and simply needs a new battery. One deep discharge can effect a battery forever.

Newer cars, in general, will drain their 12V batteries more quickly than old cars, because they're never truly off. Phone app connectivity, EU mandated Emergency Call systems, keyless entry, etc. all draw small amounts of current even when the car is parked.

Did her last car have those features?

That said, 10 minutes to the shops every second day should be fine to keep the battery topped up, as the ECU will recognise the low state of charge, and charge the battery more aggressively for that 10 minutes.

I can guarantee you that Toyota will never, ever stand over minimum driving periods in writing, even if the mechanic is correct, and they see it from time to time. I work in automotive electronics, and while I can't post the full quote, I can say that I'm looking at a spec here from a major OEM which states "…consideration must be given to customers who drive vey little…"

Is the car being manually put into ECO mode? This can/will deo everything it can to save fuel, and may limit the battery charging, and is for when you know you'll be doing a log drive say, and don't want to unnecessarily waste fuel charging the battery as quicky as possible at the beginning of your journey.

You could try and take out the keyless entry fuse, and if there is one for a telematics unit (E-Call / Phone), to see if that helps, but again, these will be a feature of newer cars too and may cause error codes on the car depending on how they're powered and monitored.

Again, think it's simply a bad battery, but an elderly person I know uses a trickle charger to keep their second which they really never use, topped up. A simple magnet charging adapter makes life very easy. https://www.amazon.co.uk/ChargeSafe-Magnetic-Trickle-Charger-Adapter-Black/dp/B0CV3DLFRX

yagan

https://www.boards.ie/discussion/comment/122579054#Comment_122579054

Her current Toyota is 2019.

Her previous Lexus was mid 2000s I think. I only drove it once but we never heard about it failing with anything.

There's no point talking with her about trickle feeders etc. she just doesn't understand why Toyota would allow this to happen.

As I said previously I took it to a Toyota dealership to get batteries tested and they said nothing was wrong.

kirving

https://www.boards.ie/discussion/comment/122579074#Comment_122579074

Adding a couple of months for manufacture, delivery, etc - the car is between 5 and 6 years old now.

It is on it's original battery? If so, it's time for a new one.

There is only so much testing that a dealership will be willing and able to do in the time allocated for a service. The dealer isn't going to admit that their testing capacity is limited, and advising a long dirve every so often is really just trying to save her a few quid as they don't want to dump a bill for a battery "just in case" on her.

The fact is though, the car isn't starting, and without an other obvious fault - the default course of action is to swap the battery.

Again, her older car is very unlikely to have some of the features of the new car which can and do cause some battery drain - that's not necessarily an issue with Toyota Hybrids, and so any new car could, and likely will have the same issues.

tabby aspreme

The 12v battery for Toyota hybrid's is a 35AH AGM battery, the one in the picture came from a 2017 Auris and lasted about 6 years before it needed to be replaced, 180 euro from Toyota, the battery was unable to start the car a few times when the ignition was on and the fan or wipers running, but when the car was switched off for 10 minutes or so it would have regained enough power to start it, sold the car recently with 280k and bought another Toyota as it was totally reliable.

yagan

https://www.boards.ie/discussion/comment/122579160#Comment_122579160

The Toyota dealer tested the battery and said it's fine.

I don't know know how many ways I can tell you the same but of information.

Other posters have said Toyota dealerships are telling people their car needs an hours drive each week.

This didn't happen with her previous Toyotas and Lexus cars. My 15 year old wreck doesn't need a weekly drive. Ive left iit in an airport carpark for a month and it fired up on first turning.

User1998

https://www.boards.ie/discussion/comment/122579527#Comment_122579527

Surely replacing the 5 year old battery first instead of spending thousands upon thousands to change cars is a better option? You might get another 5 years out of it before it goes dead again. And if not you can come back and say I told you so. It will have saved you thousands in depreciation even if it only lasts a year. But if money is no object then best of luck with the new car.

kirving

https://www.boards.ie/discussion/comment/122579527#Comment_122579527

You say that the battery is "fine", but the fact of the matter is that it doesn't start the car every time.

A full test of the battery would include leaving it sitting idle for 2-3 days as your aunt does between drives - which wouldn't be in the interest of most dealers, and I seriously doubt was done. Do you have a copy of a report from a dedicated battery tester, or did a mechanic just say it was "fine"?

You didn't know yourself that the car even had a 12V battery, or why it has one in addition to the HV battery, so with the best will in the world I don't think you're the one to be advising her to change away from probably the most reliable car on the planet, costing thousands in depreciation, to solve a problem she will most likely have in a different car of the same age too.

I've explained in detail why a newer car will drain batteries faster than an old one, and I (and other posters) have tried to be helpful in suggesting that the battery is replaced which in all likelihood will solve the problem, but you're more interested in an entirely new car.

How many times has this happened? You said "initially" and then "again", is that twice, or more?

You also said "newest version" and "new Toyota", but you have since said it's a six year old car.

Daveq

My wife's aunt was the same, 3 previous Toyota hybrids, 2 with keyless. No change in driving style, distance or duration. But her latest Yaris Cross let her down 3 times after only a few months old, Toyota said drive more. The 3rd time it wouldn't start on her way home from shopping and she had enough, Toyota eventually replaced the battery and she thinks they said they done something else but not sure what. Nearly a year later and again no change in driving but 0 problems. So whatever was done, larger battery capacity or whatever, it fixed it.

yagan

https://www.boards.ie/discussion/comment/122579675#Comment_122579675

She shouldn't have to drive it more than what she was used to with her pre hybrid Toyota.

yagan

https://www.boards.ie/discussion/comment/122579675#Comment_122579675

If they're not putting in decent batteries at the start it makes me wonder else are they skipping on.

selectamatic

https://www.boards.ie/discussion/comment/122577788#Comment_122577788

It's nearly too little for most modern cars. The amount of tech that now sort of runs in a standby yet always on mode while the car is off is the issue. It's a big issue in the Toyota hybrids because the 12v battery is small.

Simpler older cars had less of this and also had in general 12v batteries that were a size or two bigger than the car would even need to simply start. So it wasn't really an issue.

My advice would be get the measuring tape out and find and fit the largest Ah battery you can to the car. I see it mentioned online that some are putting 52Ah batteries into the Toyota chr in place of the factory 45Ah. I'd be seeing if you could even go a size bigger If at all possible. If ya can't do this then bring the car to a regular mechanic and explain the situation. Dealers won't do this and would be way dearer anyways.

You're going down a blind alley on the Toyota hybrids being unreliable in general thought process.

They're literally one of the most reliable family of cars on the road.

Just last week a stat on the top 3 highest cumulative mileage yet still on the road cars in the UK came out.

1. VW Passat's

2. Toyota prius'

3. Skoda Octavia's

yagan

https://www.boards.ie/discussion/comment/122580038#Comment_122580038

Look Toyotas may be reliable, but obviously the new ones aren't reliable in the same way her old nom hybrid Toyota Lexus were.

From what I've read on Toyota owner forums upgrading the battery like you suggest from what Toyota installed one is the best solution.

The best problem for aunt is that her favourable opinion of Toyota is tarnished. She wanted this to be her last car before she hung up her keys. She would not have chosen if the dealer had explained that it would need weekly attention. She visits relations for weeks/months at a time and the car wouldn't get used, but restarting had never been a problem with her previous Toyotas.

They're making a different product from what they used to.

selectamatic

https://www.boards.ie/discussion/comment/122582276#Comment_122582276

Ya everyone is making a different product for the European market compared to what they used to unfortunately or fortunately depending on how ya look at things. It's the level of tech in modern cars now.

Changing/upgrading a 12v battery to hopefully fix a problem is trivial in the grand scheme of things when you compare it to some of the possible repair bills you could be landed with in other alternative cars.

But look if she's hell bent on changing the car and willing to absorb the financial hit then there's nothing wrong with that, after all it's her decision and whatever makes her happy should be the priority.

Realistically she should go for a full electric car considering the miniscule amount of driving she does although you'd need to be sure it has features built in to insure the 12v battery can hack the super short trips. As far as I know this scenario was an issue on some electric cars before.

Failing that a simple bog standard exceptionally low on tech automatic naturally aspirated petrol car should be the target. Not exactly the easiest thing to find these days.