Hi Ann,

I haven't had this issue specifically with the Yaris Cross, although I have had a flat 12v battery on many occasions! I would imagine that if the 12v battery is flat then it can't power the electrics in the car and that is why the boot opening is an issue.

Sometimes, running the car in the driveway is not enough as the petrol engine needs to kick in to charge the 12v battery. I find it necessary to drive the car (motorway if possible) for a good 10-15 minutes or a few junctions and that seems to do the trick... until next time...

I also have a battery boost pack that I keep to hand which can be connected to the post under the bonnet to jump-start the car.

Hope this helps! 😊

Hi Val, thank you for the info. Had I known the Yaris Cross Excel had this type of issue maybe I wouldn’t have had this particular model and perhaps an alternative that didn’t rely on the 12v batter for operating the boot and apparently the door opening too. The salesman was aware that I’m retired and only do a few miles each day /year. I’ve read it’s possible to have a Toyota approved 30v battery installed (at a cost but may make the warranty void?). What portable charger have you got?

Hi Ann,

The problem is not limited to that particular model unfortunately. I have owned CHR's as well with exactly the same issue, as like you, I don't drive many miles at all. The issue becomes worse when it is cold in winter as the 12v battery loses charge faster. These cars have so many electrical gadgets and features now, it really puts the 12v battery through its paces!

Another thing you could check if you have a dashcam, ensure parking mode is switched off in the dash cam settings, as this can drain the battery recording movement when the vehicle is stationary. Also switch off the air con, fans, interior lights, etc. when leaving the vehicle - anything that would normally start immediately when starting the car.

I have replaced the 12v battery in the CHR's previously with larger aH (Ampere-hours) one, this shouldn't void any warranty's on the car as it does not change or enhance the performance of the vehicle.

I have a Silverline jump starter, they are reasonably priced on Amazon: https://amzn.eu/d/06DAlmMN

Kind regards,

Val ☺️

Hi Val, thank you so much for your tips. I was really considering changing my Yaris Cross Hybrid as it was getting so frustrating not being able to open the car boot. No way of overriding it either and apparently the 12v can mean not being able to open the car doors either (have you had this issue?). I think I’m going to do two things before making my mind as to whether I sell - change the battery to a 30v and also purchase a jump starter to keep in the car - just in case!! I can research but from your experience how long does the jump starter last before you have to recharge this? I guess it’s a case of keeping it fully charged?

Thank you for your replies as I find this more helpful than the advice I was given at the dealership.
Regards, Ann

Hi Ann,

Thank you for your message. I'm so glad you found my previous advice helpful!

However, I want to clarify something very important: do not use a 30v battery in your Yaris Cross Hybrid!! Your vehicle is designed to operate with a 12v battery, and using a 30v battery would almost certainly cause significant damage to your car’s electrical system, potentially leading to very costly repairs.

Regarding the issues you're experiencing with the 12v battery, you're absolutely right that a weak or failing 12v battery can cause problems with accessing your car, including opening the boot and even the doors. This is a known issue with many modern vehicles, as they rely heavily on electronic systems.

Here's what I recommend:

1. Replace the 12v Battery: Get a high-quality 12v battery with a larger ampere-hour (Ah) capacity - I can recommend GSF https://www.gsfcarparts.com/. This will give you more reserve power and can help prevent some of the issues you've been experiencing.

2. Purchase a Jump Starter: The Silverline jump starters are compact, easy to use, and hold a charge for a long time. Typically, mine can last several months on a single charge, but it's a good practice to check and recharge them every few months to ensure they're always ready when you need them. I bought mine years ago and it has jump started each one of my Toyota's first time, every time. It's also a good idea not to store the jump starter in the car, but do take it with you if you are going away on holiday with the car, for example.

3. Regular Maintenance with Toyota Service: If you have a Toyota Service Plan, your vehicle's electrical system is regularly checked and maintained. Sometimes, a problem with the hybrid system or other electrical components can also affect battery performance, if you are concerned you can mention it during a service.

I hope this helps you make an informed decision about your car. If you have any more questions, feel free to ask!

Best regards,
Val ☺️

Hi again Ann!

Just a side note that the key fob/remote controller for your car should have a key that you can pull out of the fob that unlocks the door.

Kind regards,
Val ☺️

Thanks Val once again. My car has just had its first service and I’ve got a three year service plan. The boot was working fine for the first 10 months then it is a bit hit and miss as to whether it works or not. As I had the service at the local Toyota dealership and took it back twice, they replaced the existing 12v battery for a new one. All was well for two days then it started happening again.

I will definitely consider buying a portable jump start to keep to hand should it happen when I’m out.

I guess lesson learned that it’s something worth asking when purchasing a new car although the dealer was aware I was a low mileage user. Apart from that it’s a lovely car and will have to learn to live with all the glitches that come with it.

Thank you again for your advice which has been most helpful.

Regards
Ann Waed