Flat Battery

Faults and Technical chat for the Toyota Yaris Cross
Cuddles
Posts: 21
Joined: Fri Nov 17, 2023 8:10 pm

Post by Cuddles »

Yesterday I bought a voltage meter that plugs into the cig lighter. It showed 12.6v when the battery monitor 2 (BM2) was showing 12.3 before starting engine so close enough. It shows 14.5v when driving so is charging OK. Between that and the BM2 I should be able to judge when to put it onto the CTEK for a few hours.
Don't forget that after 1 year of allowing the battery charge to drop the sulphor build up between the lead plates will have grown and thus making charging and maintaining charge worse so the CTEK will keep those plates clean on steps 1-2 by removing the sulphor and keeping the battery as new. I will put it on the CTEK every 2-3 weeks whatever the monitors say.
My GR Yaris is now 3 years old and just fit a BM2 and is on full charge. The CTEK after a run out takes only an hour to go through the full 7 point proces to be fully cleaned and charged which makes me believe it is in good condition even though it has only done 7k miles in 3 years. My concern with the Yaris Cross was and is that battery problem which is why I need to be proactive with it to keep it as new. CTEK cable fixed to battery that runs into the boot. Pick a day when not using it for a few hours then plug it in to CTEK with 2.5m extension either through kitchen window or letterbox - easy. Noco jump starter in glove box. I don;t think I can do any more other than fit the Yuasa 45 amp battery I think I suggested earlier. If I am back here in a years time saying it has failed like Rob above then my 25 years of buying Toyotas may be over. The only problem with that is many other makes as well as full EVs have the same problem. Cars without starter motors usually have small batteries.
It isn't just us. This problem is all over the different forums but most people are not aware of the problem and CTEK + BM2 + Volt meters and NOCO jump starters will help make it less of a problem when you aware of it and what you can do about it.

Jenny_L
Posts: 1
Joined: Thu Apr 18, 2024 3:33 pm

Post by Jenny_L »

I bought a 71 plate Yaris Cross last June. I've had no problems with the 12V battery, despite only driving 400-500 miles per month... until I had an operation in March and couldn't drive for 5 weeks. I went into Jemca Reading before my op and specifically asked, do I need to do anything to maintain the car for the next few weeks, eg. get someone to drive it once a week etc? I was advised, just turn it on at least once a week and let the engine run as long as it wants, to top up the hybrid battery. Nothing was said about the 12V battery being so naff that it would go flat within 2-3 weeks. Which it did. Toyota Assist (AA) jump-started it and advised me to leave the car in 'Ready' mode for at least 2 hours (!) and then again for 30-60 minutes every other day, given I still couldn't drive it. This indeed charged the battery enough to keep it functional: the AA man demonstrated how the hybrid battery was trickle-charging the 12V battery, and periodically the engine fired up for a few minutes to recharge the hybrid battery. Big downside, of course, is that either I sat in the car for 30-60 mins (or 2 hours on the day the AA came) or trusted that no-one would nick the car, as it needed the key in it to stay in 'Ready' mode and it refused to be locked with the spare key while a key was still inside but with no-one sitting in there! 🙄 (too flippin' clever for its own good).

The AA man said the battery was probably defunct, if it went flat in 3 weeks. I phoned Toyota to ask for a battery replacement, and was offered next day... but when I mentioned "under warranty", the man on the phone quickly changed his tune and said this would need booking in for a battery check first, which they couldn't do for 2 weeks! The 'next day' job would have been a non-warranty replacement at a cost of about £150 to me. Not impressed at Toyota's transparency (ie. utter lack thereof).

I drove it (yay!! 😁) to Jemca Reading yesterday. They did the battery check: their machine told them to charge it overnight. This morning the conclusion was that it's absolutely fine and just needed charging properly. Guess what? I was told that I don't drive it enough blah blah blah - same weary excuse clearly being trotted out to everyone; but this wasn't my problem, it was due to the car being unused for 2+ weeks. The service lady also explained that, when the car is not in use, the 12V battery will be used to trickle charge the hybrid battery (I guess the hybrid battery is a more expensive failure?), so that would explain why the 12V battery died. And yes, she said they recommend a solar battery charger, especially if the car is left unused when you go on holiday etc. Other car maintenance websites point out that cars these days have so many systems running in the background - keyless entry, alarms, wi-fi, and numerous other processes - that the 12V battery is being drained far more than used to be the case. Maybe the Toyota batteries are inferior and so drop charge quicker?

It's a shame that Toyota can't train its staff to inform prospective buyers about these things. There's certainly nothing in the manual about it, that I can find. And it's a shame that the advice I got in March was so severely inadequate. Seems to be the way of dealerships these days, hey ho.
Cuddles
Posts: 21
Joined: Fri Nov 17, 2023 8:10 pm

Post by Cuddles »

Has anyone said to their dealer that they would like to have a better make battery with a higher amp than the one Toyota fit at the factory. I am sure I have read that Toyota won't do that for some technical / warranty reason.
It seems to me that a new - better - stronger battery is the first step to take as in the video I posted earlier.
I would pay for the battery myself if they would fit it free.
Had mine for two months now and used the CTEK charger yesterday. This morning the BM2 - battery monitor 2 said the battery was at 79% and 12.1 V.
Really nice car but this is a slight worry. My niece has had many failed starts with her Hyundai and needed jump starting.
Anyone buying EV or hybrids need to be warned about this issue unless they do good long drives to work every day.
My Noco gb40 in the glove compartment is clearly an absolute necesity.
I am annoyed at this situation as it is taking the shine off the new car when I should just be enjoying it fully even though it hasn't let me down. I intend to push my dealer to allow me to upgrade the battery to a good Yuasa if possible.
PS01
Posts: 2
Joined: Tue Mar 26, 2024 5:01 pm

Post by PS01 »

We have had our YC Excel since late March. We don't do huge mileage and a lot of short journeys. Having read the Forums I had a CTEK plug fitted by the dealership before collection (just tucked under the back seat) - incidentally the cable has to be connected to the positive terminal and earthed elsewhere, not on the negative battery terminal, check CTEK's website/YouTube. In general the car maintains a range of 12.3 - 12.4v (Mid level battery charge) however I had keyless entry switched off when we got it and I am careful not to use radio etc without car being in READY mode. I do carry a GB20 booster.
I do check the voltage on a regular basis and also use a CTEK charger from time to time for a boost/battery conditioning, usually shows 12.8v "Full" when measured post completion.
I learned the hard way about battery failure - my son's 2013 Yaris suddenly refused to start after 2 years of not showing any problems - AA boosted and restarted it - I had the battery replaced and I put a solar charger on it (AA 4.8W) via OBS 2 which keeps the battery well topped up. The Yaris sems to maintain it's voltage a little better i.e. recently it has stayed close to "Full" at 12.7v rather than slipping to Mid like the YC for around a week since I last used to solar charger but I guess bearing in mind it's age it has less systems drain on it.
I have attached a photo showing the plug and meter arrangement in the YC, I also had a similar plug fitted to the Yaris.

IMG_20240514_140746816.jpg

JeffF
Posts: 4
Joined: Fri Apr 28, 2023 11:45 am

Post by JeffF »

Hi I have had my Yaris Cross just on a year when I had my first flat battery, I only use it 3-4 times per week and often only for short journeys and have no intention of changing so I now use a solar panel to maintain the voltage which works quite well and using a cigarette lighter powered volt meter just to keep an eye on the voltage which it usually holds to about 12.7 volts but without the solar panel I note this drops at a alarming speed so decided to ask my dealer to fit the yuasa YBX5202 45 ah battery mentioned in a earlier post but predictably they said as a Toyota Centre (Steven Eagell} they will only supply and fit the recommended 35 ah battery which which was subjected to a recent bulletin part number upgrade as per attached:

20240515_120152.jpg

35ah

has anyone else had a similar experience with this battery or managed to persuade the dealer to fit the former one?
Cuddles
Posts: 21
Joined: Fri Nov 17, 2023 8:10 pm

Post by Cuddles »

The Yuasa battery is a better quality so that is a good thing if you have had it fitted.
Am i correct in thinking this Yuasa 35ah battery above is the one they will / did fit for you?
I wonder if they would fit the YBX5202 45 ah battery if we agreed to pay for it and they fit for free or is there a reason a 45ah can't be used but a 35ah can?
Have you got a link or ID number for the toyota bulletin regarding the battery replacement.
Thanks.
JeffF
Posts: 4
Joined: Fri Apr 28, 2023 11:45 am

Post by JeffF »

The only one they would fit Is the one in the pic which as you can see is still only a 35ah one but is supposedly the upgraded one, I asked them to fit YBX5202 45 ah one but said they can only fit the recommended one so am now looking at a bosch 42ah recommended by the AA but it says it's not suitable for a stop/start car I thought that may include a Hybrid so need to get that confirmed. No I don't have a link sorry that's what the parts mgr. told me.
JeffF
Posts: 4
Joined: Fri Apr 28, 2023 11:45 am

Post by JeffF »

The AA have confirmed their battery is not suitable despite listing it when you enter Reg. No. they went further to say they are not currently fitting any batteries to hybrid cars. My dealer Steven Eagell are not prepared to fit any other battery than the recommended one
Cuddles
Posts: 21
Joined: Fri Nov 17, 2023 8:10 pm

Post by Cuddles »

Thanks for that jeffF. It clearly is a problem at the moment and all car manufacturers haven't got to grips with this issue.
Had mine only 3 months now and CTEK charge it once a week. The the voltage on my phone this morning using the BM2 (battery monitor 2) said 12.45 volts so OK but the condition was 70%. I am not sure what that figure means.
The CTEK when connected goes to full charge withing 5 minutes and goes past the first "cleaning" stage in seconds which tells me it is clear of sulphor build up which I see as good.
Maybe they are simply cheap, crappy batteries and an upgrade to Yuasa is a good idea.

When they said they would supply and fit the Yuasa do you mean they will do it under warranty / bulletin upgrade or will you have to pay.
Will they do it if I ask them to or do they need to have the car in for checks after it failing to start a few times.
I would quite like the upgrade before it fails just for peace of mind.

Thanks for your time. Much appreciated.
JeffF
Posts: 4
Joined: Fri Apr 28, 2023 11:45 am

Post by JeffF »

No I don't think they will change it under warranty without testing and I find that their test rarely fails it, I had a CHR previously had the same problem after nearly two years had to get the AA out who tested the battery and said it was no good, he was an ex employee of my local dealer, I took it in but they retested it and declared it ok, I decided to change it the car for the Yaris Cross which had a 4 month waiting list at the time so I said I would only go ahead with the deal if they fitted a new battery which they did and unsurprisingly I had no further problem. I am still undecided on how to go forward with this one.
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