12v battery maintenance, issues, etc.

[Dala]

Toyota has a recommended point in the manual - see picture 
robo1 wrote: 
There’s are some  nuts used to anchor the shock absorber close to the fuse box.  Using a multimeter they do show they are grounded. The leads are long enough for this.

[Jasper.]

Thank you all for your replies , that was much more than I was expecting..

Really useful info.. 😊

[Roy124]

23 hours ago, Catlover said:

 However, £99 is a lot for a jump starter. 

If you have to buy it. 

[Dala]

GB40 is not needed for our cars
GB20 $ 79.95 - that's enough
Designed for car, boat, motorcycle, RV and others with gas engines up to 4 liters.
Compact but powerful lithium starter with a power of 500 A up to 20 jump starts on a single charge.
https://no.co/gb20

[Devon Aygo]

The under bonnet connections are to provide a 12v power source for starting when the cars Battery is flat, they are not for charging the cars 12v Battery charging this is to be done directly 

[bathtub tom]

43 minutes ago, Devon Aygo said:

The under bonnet connections are to provide a 12v power source for starting when the cars battery is flat, they are not for charging the cars 12v battery charging this is to be done directly 

So what's between the under bonnet connections and the Battery?

[Devon Aygo]

1 hour ago, bathtub tom said:

So what's between the under bonnet connections and the battery?

The under bonnet terminal ( AMD ) is directly connected to the DCDC converter

[Stopeter44]

So when people want to use something like the CTEX chargers that are popular here, where do they connect?

[Devon Aygo]

Directly to the 12v Battery under the (RHS) rear seat

[Stopeter44]

1 minute ago, Devon Aygo said:

Directly to the 12v battery under the (RHS) rear seat

Ok, is that easily done , or does the seat have to be removed?

[Devon Aygo]

Seat base is clipped down in two spots, carefully feel along between base and trim until you find the clip point then with hands either side of clip point pull up sharply, it is best if you can create a permanent connection to the Battery with an accessible 🔌 most charger brands offer something 

[Cyker]

Nooo, you don't need to do that in the Mk4 - They added an access panel!  

It's on the base of the rear passenger seat, on the opposite side to the fan vent for the traction Battery. (On mine it's on the driver's side but not sure if the same or reversed on the LHD models)

You need to remove two screws from the door-side of the panel, which may be a bit awkward because of the lack of space in the rear, then it's just a matter of pulling on the inner-side to pop it free of the clips.

To be fair tho', access is probably easier if you pull the seat out as access via the panel might be too tight to do anything useful without removing the Battery out of its little cubby hole first, and it's quite heavy to wiggle out!

[Catlover]

So it may be best, as Devon Aygo says, to create a permanent connection to the Battery that is easily accessible. I know that there is an accessories available to do just that for the CTEX 5 charger.

[Joby1]

Hello

I’ve have a 2020 new model yaris hybrid. In the last 10 days I’ve had to get roadside assistance twice as the 12v Battery was dead. First time the car had been stationary for 3 days, the second time 2 days. Dealership today checked if there was a electrical fault (no) but said it needed a full charge up, which they did. Issue is - apparently flat 12v Battery is a hybrid issue (due to of engine running from hybrid Battery mainly it doesn’t fully charge the 12v.) Apparently there have been cases of people going on holiday for 2 weeks, coming back to a dead battery. I’m concerned as over the next few months due to work I will be leaving my car a few times for a week or two at the airport.

Seems a serious design fault of Toyota when they have a strong reputation for reliability!  
Has anyone else experienced this? Does anyone have a solution? Am thinking I may well be better to sell the car and start afresh. 
Thank you for any advice. 

[Dala]

Don't have an alarm, car cameras, etc. installed?

[Joby1]

No. Dealership said due to more use of lights etc in dark weather

[Roy124]

Joby, many threads.  It is not your problem, a Yaris problem or even a Toyota one. And running the engine and not charging is a red herring. 

I am guessing you are a new owner.  You don't know whether it had a flat Battery issue before which will have weakened the Battery. 

The approved solution if you are not running is to put it in to Ready mode for an hour.  The motor will run for short periods to charge the HV Battery.  It will in turn charge to 12 v battery. 

Best result when doing this is to switch off heater, radio etc.  You are also advised not to leave the car unattended.  

You are right to wonder about leaving the car at the airport.  You might consider getting a small backup battery. All it needs to do is to start up the car systems. 

 

[Dala]

Do you drive short rides? For example, twice a week only 5 to 10 minutes?

[FROSTYBALLS]

In April 2020, Toyota gave the following advice on Battery maintenance due to cars being left for long periods without use: https://mag.toyota.co.uk/coronavirus-toyota-hybrid-car-maintenance/

It isn't just a hybrid or Toyota problem, as petrol cars and cars from other manufacturers may be affected as well. For example our 2020 i20 comes up with a Battery drainage warning a few minutes after the engine is turned off and the multimedia unit is still on.

What you haven't said is whether your normal usage is short journeys, etc. These together with electrical systems like lighting being on a lot, etc, don't help provide the Battery with a full charge.

Yes, you can sell the car, but may have a similar experience with the replacement - who knows ?

[Joby1]

Thanks everyone for your advice. 
daily I usually do 2 x 10 mile drives. 
 

I am a new hybrid owner but had my previous petrol yaris 14 years, 135,000miles. No Battery problems. 2019 left it for 5 weeks whilst in NZ, started first time on return. 

[Roy124]

Joby, you almost have to unlearn what you new. Hybrids are a step change in specification and understanding. The Battery issue might be said to be a fundamental step change in much the same way that Diesel car drivers had to learn about DPF and then Ad Blue. 

Things will change. 

[Mikw]

I can only advise this :

About once a week leave it in ready mode for an hour. It's the short journies that kill the Battery. So, if you've done a couple of short drives then - next day - give it an hour in ready mode, and that should last a week or so.

The key is "ready" mode really. If you wash the car yourself, leave it in ready mode, the engine will only come on a couple of times over an hour. Same if you put the car in the garage, don't switch off when you get out to open the garage door.

It seems to me that short periods in Ready mode deplete the Battery, but longer periods in ready mode keep it topped up.

[CPN]

40 minutes ago, Mikw said:

It seems to me that short periods in Ready mode deplete the battery, but longer periods in ready mode keep it topped up.

...and you should also add that longer periods in ready mode knock hell out of the overall fuel consumption figure per tankful! (because it's standing still - going nowhere)

[Catlover]

I don’t think so Colin. I have done the one hour in ready mode and the engine did fire up but not many times and not for long. It’s not like the engine is running all of the time.

[Cyker]

If it's in winter and the HVAC is on then it would drop the mpg quite dramatically, but with it off or in summer it is surprisingly frugal still; When I was stuck in yet another M25 closure for 2 hours (THANKS SMART MOTORWAYS) last summer, I think I only lost 1-2 mpg just sitting there in Ready mode with the AC on (albeit in eco mode) listening to music