Toyota Hybrid 12V Battery Issues
Discussion
Just watched a report on The Morning Show about Toyota 12V batteries failing if the vehicle isn’t driven enough. Their recommendation is to do a 2 hour drive weekly to keep the battery charged!
Speedqueen has a 2023 Yaris hybrid and does ~2000 miles per annum.
Twice I have pumped up the tyres using an electric compressor, and the car has failed to move afterwards. It’s frustrating, because unlike a conventional starter motor, you get no warning.
Thought I’d check to see if there was already a thread and found this one from 2017!
https://www.pistonheads.com/gassing/topic.asp?h=0&...
Staggered that Toyota, being a leader in hybrid technology, hasn’t solved the problem in the last decade.
The motion battery is fully charged, so there are plenty of electrons available, just in the wrong place. It appears that there’s no alternator, so keeping the engine running is not a solution. That’s why you can’t use a hybrid Yaris to jump start another car.
There is apparently an uprated battery. Does Toyota fit those FOC on cars > 3 years old? Are the solar charging thingys good enough? Time to invest in a trickle charger?
Does anyone have any similar experience, particularly how to resolve the issue. Buying a footpump today 😊
Speedqueen has a 2023 Yaris hybrid and does ~2000 miles per annum.
Twice I have pumped up the tyres using an electric compressor, and the car has failed to move afterwards. It’s frustrating, because unlike a conventional starter motor, you get no warning.
Thought I’d check to see if there was already a thread and found this one from 2017!
https://www.pistonheads.com/gassing/topic.asp?h=0&...
Staggered that Toyota, being a leader in hybrid technology, hasn’t solved the problem in the last decade.
The motion battery is fully charged, so there are plenty of electrons available, just in the wrong place. It appears that there’s no alternator, so keeping the engine running is not a solution. That’s why you can’t use a hybrid Yaris to jump start another car.
There is apparently an uprated battery. Does Toyota fit those FOC on cars > 3 years old? Are the solar charging thingys good enough? Time to invest in a trickle charger?
Does anyone have any similar experience, particularly how to resolve the issue. Buying a footpump today 😊
This is a known issue with the Yaris Cross. Too many electric gizmos apparently. Recommended Toyota to a friend. Failed to start after 2 weeks. Solution offered by the Toyota was a trickle charger that they would supply. They told him it was a known issue. I told him to reject it as that was not really a solution.Toyota agreed with no pressure needed. He bought another Mini Clubman for his wife
This issue is more widespread on the Yaris due to Toyota specifying a stupidly small 35Ah battery - it looks like something you'd see on a motorbike! The issue with Toyota hybrids is that they use an inverter to charge the battery, which doesn't run continuously like an alternator would, so you need to drive it for a certain amount each week to keep the battery at minimum charge. You can use trickle chargers or solar chargers to get around this.
Also worth noting if the battery has gone flat once or twice it will go flat more regularly as the cells have degraded and lose capacity, and will need replaced.
My Corolla hybrid was bought 2nd hand and came with a bad battery, probably from sitting on the forecourt for too long. Toyota replaced it with a bigger 52Ah battery under warranty and I've not had any issues since.
TBH, if you're only doing 2000 miles a year a Toyota hybrid is not the ideal car. Better with either a BEV or a small pure petrol engine.
Also worth noting if the battery has gone flat once or twice it will go flat more regularly as the cells have degraded and lose capacity, and will need replaced.
My Corolla hybrid was bought 2nd hand and came with a bad battery, probably from sitting on the forecourt for too long. Toyota replaced it with a bigger 52Ah battery under warranty and I've not had any issues since.
TBH, if you're only doing 2000 miles a year a Toyota hybrid is not the ideal car. Better with either a BEV or a small pure petrol engine.
Always,always have a decent quality jump pack to hand. And also know the procedure for getting into, and accessing the 12v battery if the car is dead on its feet. Just something additional to add to the mental checklist if you claim to be a car enthusiast ( yeah, I know it’s electric etc etc)
We had a 2025 Premiere Edition.
The car does alert you via the My Toyota app before the 12v battery is too low to start the car.
Even the 'upgraded' battery goes flat. Eventually you will be opening it with the emergency key blade too.
The official 'fix' is to waste fuel running the car on your drive for at least an hour every week.
The thought of fannying around with solar or trickle chargers on a brand new shopping car is insulting.
I was at the point of having to use a NOCO jump pack if it was left for more than 2 days.
Unless you do lots of miles, get rid.
The car does alert you via the My Toyota app before the 12v battery is too low to start the car.
Even the 'upgraded' battery goes flat. Eventually you will be opening it with the emergency key blade too.
The official 'fix' is to waste fuel running the car on your drive for at least an hour every week.
The thought of fannying around with solar or trickle chargers on a brand new shopping car is insulting.
I was at the point of having to use a NOCO jump pack if it was left for more than 2 days.
Unless you do lots of miles, get rid.
Edited by Shinysideup on Monday 12th October 12:03
ashenfie said:
Who knew batteries go flat. For sure my old school weekend SLK had a solar charger attached during the winter months, else the battery got killed. I can't see long period of inactivity doing much of the life of any Battery hybrid or not. All car benefit from being driven regularly.
You honestly think, "do a 2 hour drive weekly to keep the battery charged!" - is reasonable?Hm, I'm surprised they don't have a link of some sort between the high voltage battery and the 12V one.
I've been googling a bit about it as I was getting random errors which screamed "12V battery low" to me. Sure enough, any hybrid or EV can suffer from this if you're only doing short journeys. Fortunately, many hybrids and EVs can charge up the 12V battery via a DC to DC link even if you just sit in "idle" with the car switched "on" and ready to drive (so not just in ACC) eg in a Golf hybrid, it will say "READY" rather than having random amber lights on because you haven't turned the key fully.
So to solve my low battery, I just sat in the car for 30 minutes with it ready to drive while I played on my phone (to clarify: the petrol engine was off, 0 revs; if I had put it into D or R it would have rolled forwards under the electric motor). Errors like "WARNING: PUT IN P AND ALERT WORKSHOP" (or similar) stopped randomly flashing up during my next few journeys.
Also, apparently, on the Golf at least, regularly charging it up will top up the 12V battery via the charger as well. Meanwhile, i8 owners are recommended to just keep their cars tethered to maintain the 12V battery. (This may or may not be a valid thing for non-i8 owners who have a different hybrid car - I think the VAG hybrid system can drain the 12V battery if you leave it connected for days once it's topped up as it goes into standby mode? Can anyone confirm?)
Edit: more and more, I think ICE are easier to manage. Just drive it at least once a week, no need to plan where you're going to fill up or faff about with managing your home battery energy or who's using the charger today. Fill up, go, job jobbed. If you have a busy life and earn a stack of money, just buy a V8 and enjoy life.
I've been googling a bit about it as I was getting random errors which screamed "12V battery low" to me. Sure enough, any hybrid or EV can suffer from this if you're only doing short journeys. Fortunately, many hybrids and EVs can charge up the 12V battery via a DC to DC link even if you just sit in "idle" with the car switched "on" and ready to drive (so not just in ACC) eg in a Golf hybrid, it will say "READY" rather than having random amber lights on because you haven't turned the key fully.
So to solve my low battery, I just sat in the car for 30 minutes with it ready to drive while I played on my phone (to clarify: the petrol engine was off, 0 revs; if I had put it into D or R it would have rolled forwards under the electric motor). Errors like "WARNING: PUT IN P AND ALERT WORKSHOP" (or similar) stopped randomly flashing up during my next few journeys.
Also, apparently, on the Golf at least, regularly charging it up will top up the 12V battery via the charger as well. Meanwhile, i8 owners are recommended to just keep their cars tethered to maintain the 12V battery. (This may or may not be a valid thing for non-i8 owners who have a different hybrid car - I think the VAG hybrid system can drain the 12V battery if you leave it connected for days once it's topped up as it goes into standby mode? Can anyone confirm?)
Edit: more and more, I think ICE are easier to manage. Just drive it at least once a week, no need to plan where you're going to fill up or faff about with managing your home battery energy or who's using the charger today. Fill up, go, job jobbed. If you have a busy life and earn a stack of money, just buy a V8 and enjoy life.
Edited by Hoofy on Monday 12th October 12:32
Griffith4ever said:
ashenfie said:
Who knew batteries go flat. For sure my old school weekend SLK had a solar charger attached during the winter months, else the battery got killed. I can't see long period of inactivity doing much of the life of any Battery hybrid or not. All car benefit from being driven regularly.
You honestly think, "do a 2 hour drive weekly to keep the battery charged!" - is reasonable?Griffith4ever said:
ashenfie said:
Who knew batteries go flat. For sure my old school weekend SLK had a solar charger attached during the winter months, else the battery got killed. I can't see long period of inactivity doing much of the life of any Battery hybrid or not. All car benefit from being driven regularly.
You honestly think, "do a 2 hour drive weekly to keep the battery charged!" - is reasonable?My Yaris does this...if I leave it for a while the battery goes flat, and mine is not a Hybrid, funny enough my Porsche does this too, both are on optimizers when they are not getting used much.
But shock horror...not driving your car and the battery goes flat, this has been going on since cars were invented.
Just drive them now and again...its not rocket science.
But shock horror...not driving your car and the battery goes flat, this has been going on since cars were invented.
Just drive them now and again...its not rocket science.
Long running issue for sure, The two CHR's that my dad has had both did it, to the point where he bought a battery booster and trickle charger. He does a very low mileage and it rarely gets a run.
Our 2020 Yaris Hybrid has never done it, and the Toyota dealer said 'these ones are not affected by it'. but I don't know what the details of the difference are.
I believe that Hyundai hybrids have a way of back feeding the 12v battery from the traction battery to prevent the problem. I also find it astonishing that Toyota has this issue.
Our 2020 Yaris Hybrid has never done it, and the Toyota dealer said 'these ones are not affected by it'. but I don't know what the details of the difference are.
I believe that Hyundai hybrids have a way of back feeding the 12v battery from the traction battery to prevent the problem. I also find it astonishing that Toyota has this issue.
They've known about this issue long enough to have put a plan into action, what were you thinking Toyota/Lexus ruining your reputation as The most reliable vehicle make you can buy for the sake of a decent battery, which in the volumes you buy them has to be just about the cheapest voluntary recall/fix any maker could wish for.
Hopefully now national news has picked it up someone responsible at Toyota will make some calls.
Many models have the battery in the boot, in the event of a flat battery you may not be able to get in the boot, so if you have the good sense to own a jump pack keep it in the car itself.
There are jump points under the bonnet, a flip over-red cover (inside the fuse box) reveals the positive contact, use a suitable earth point for the negative lead.
High performance jump pack isn't required, you only need enough current to fire up the various relays and ECU's, the hybrid battery starts the engine.
My Prius PHEV has failed to start once, mostly my own fault due to faffing about with vehicle settings for ages, but the main issue by mistake the dash cam was on permanent parking record mode, jump starting was simplicity itself.
I also give the battery an overnight condition charge every couple of months.
Hopefully now national news has picked it up someone responsible at Toyota will make some calls.
Many models have the battery in the boot, in the event of a flat battery you may not be able to get in the boot, so if you have the good sense to own a jump pack keep it in the car itself.
There are jump points under the bonnet, a flip over-red cover (inside the fuse box) reveals the positive contact, use a suitable earth point for the negative lead.
High performance jump pack isn't required, you only need enough current to fire up the various relays and ECU's, the hybrid battery starts the engine.
My Prius PHEV has failed to start once, mostly my own fault due to faffing about with vehicle settings for ages, but the main issue by mistake the dash cam was on permanent parking record mode, jump starting was simplicity itself.
I also give the battery an overnight condition charge every couple of months.
Edited by Smint on Monday 12th October 13:28
Left my car a RAV4 PHEV for 4 months on the drive not plugged in, came back from work and it fired up first time.
I have a solar trickle charger on my dash and plugged into OBD port, keeps the battery fine. It lies flat and you can hardly see it. Also use it when camping etc to charge phone and battery packs etc.
I have a solar trickle charger on my dash and plugged into OBD port, keeps the battery fine. It lies flat and you can hardly see it. Also use it when camping etc to charge phone and battery packs etc.
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