12v battery maintenance, issues, etc.

[CruxisCore]

Interesting thing i noticed about My Aygo X charging logic. Ive always been taught with traditional alternator cars that its long drives that charge the Battery. 

But noticed the Aygo X will basically never charge with like Cruise control like driving. As soon as u lift foot Off pedal or brake or turn off Cruise, charging voltages pop up. 

Im sure its the same logic in hybrids. It aims for max fuel economy and utilize moments when there is spare power

[CruxisCore]

Given the difference with hybrids is that it would prefer to keep the energy for EV driving while with an ICE car they can just send it all to 12v. So thats why hybrids are more prone to the 12v problems as every bit of power you send to the 12v is what you couldve driven with electricity

[RickyC]

18 hours ago, CruxisCore said:

Interesting thing i noticed about My Aygo X charging logic. Ive always been taught with traditional alternator cars that its long drives that charge the battery. 

But noticed the Aygo X will basically never charge with like Cruise control like driving. As soon as u lift foot Off pedal or brake or turn off Cruise, charging voltages pop up. 

Im sure its the same logic in hybrids. It aims for max fuel economy and utilize moments when there is spare power

On an ICE car, the energy produced by alternator is proprtional to ICE ratational speed.  When you're driving on highway ( expecially if yiu have CVT gearshift ) ICE is running at low speed,  so probably the energy produced by alterantor is low and it's sent just to 12V circuit to keep all 12V powered devices working.  When you brake probably the alternator recovers the peak of energy ( like hybrids car do )  and sends to Battery. In the same way if you need to have ICE running high ( hill, start ... ) the excess of energy is used to charge Battery. 

[TonyHSD]

Hybrids propulsion has nothing to do with 12v Battery or the other way around. 
If non hybrid car has a stop start system and kinetic energy recovery alternator then the 12v Battery soc and recharge may interfere with vehicle drive but also unlikely. 
For the 12v Battery recharging in all cars engine speed does not matter. Every alternator has a voltage regulator and once the engines running it doesn’t matter if the engine crankshaft rotates at 900rom or 3500rpm on a motorway, the alternator is supplying constant 14.7v to the battery, but this can vary according to battery soc, power consumption, etc.  What matters here for the battery to get a good charge and remain healthy is time the engine been ON. In Toyota hybrids all that is similar but the different is that there is no alternator but dc to dc converter, and the engine does not need to be running but the car should be ON aka ready mode. 
Regenerative braking and acceleration, vehicles speeds etc are variable to the high voltage management.  A low 12v battery can make eventually engine running more often, because it will draw more energy from the hybrid battery and once the hv battery gets low the engine will kick in to recharge it. The 12v batteries in Toyota hybrids feed all electronics except two things, vehicle propulsion and air conditioning compressor, these two are exclusively run by the high voltage 200+ v hybrid battery located under or behind rear seat. 👌

[CPN]

3 hours ago, TonyHSD said:

For the 12v battery recharging in all cars, the engine speed does not matter. Every alternator has a voltage regulator and once the engine is running, it doesn’t matter if the engine crankshaft rotates at 900rpm or 3500rpm on a motorway, the alternator is supplying a constant 14.7v to the battery...

Exactly, the point that I was going to make...

[Phillipe]

Hi 

I purchased a 2022 hybrid GR Sports and think it is a great little car but twice in recent weeks have had to have the AA out to get me started. On the first occasion the car had been stood for 10 days and on the second for 5 days. I have been told by my Toyota agency that the Battery is fine but they need it in overnight to give it a trickle charge. This is obviously a temporary fix and the problems are going to rear their head again. The garage reckon that nothing can be done about the problem in general.  If I had been told when purchasing the car that you had to give the car a long run at least a couple of times a week I wouldn't have bought it. It even means that you can't park at an airport just as an example for a couple of weeks without calling the AA out on your return.  Has anyone out there got any advice on my predicament. 

[dannyboy413]

Loads, (and loads), of posts on this subject. You could start here -

 

[Derek.w]

Hi Phillip you can charge the Battery once a week but for a long term fix I replace the Battery with one with a higher amp hour rating then you have no problem leaving the car for 2 or 3 weeks.

You still need to give it a boost once a month os so with a charger of your choice maybe more often in winter.

I am using EFB calcium type battery Not sure if yours will be the same my replacment is 

Yuasa HSB202 Part no YBX5202  45AH cca 440 amps the old one was just 35AH.

YOUR first thing to find out is it a AGM Battery or EFB Calcium battery.

 

 

[FROSTYBALLS]

Moved to the Yaris forum.

[Guest]

I would be wary of calling out the AA repeatedly for the same issue. That doesn't help you but I know other breakdown companies are a bit reluctant with the same problem.

Not owning a Hybrid and knowing the system, is it possible to connect a Battery maintainer to the 12v Battery? I realise that's not a solution any owner should have to use, but would that save any future problems?

I thought Toyota's advice on starting batteries was poor. 

[Phillipe]

Hi olonas. Thanks for your advice

[Roy124]

23 hours ago, Phillipe said:

  If I had been told when purchasing the car that you had to give the car a long run at least a couple of times a week I wouldn't have bought it

Just to correct this as it is often quoted and is completely wrong.

First 'a long run', like a piece of string, stop when you reach the end. 

Then a 'couple of times a week'.  

The advice is actually 'in Ready mode for 30 minutes every 2-3 weeks.'  This by Toyota IE.

During lock down Toyota UK ssid:

'We recommend you put the car in 'Ready' mode for about 60 minutes before switching it off again and repeat the process at least once a week, ...'  in practice that is overkill.

[Roy124]

20 minutes ago, Phillipe said:

Hi olonas. Thanks for your advice

Phillipe, you have bought a car where you have no knowledge of how its Battery was conditioned.  It you don't have a smart charger, by all means let the garage charge it overnight. 

Once you have it back, keep a daily log. For driving record the minutes driven on each leg. Ideally use a voltmeter before starting the car each day.  If you can, take a reading every day even if you are not using the car.

If the voltage drop over several days without use is insignificant,  say less than 0.2v/week, you are good. 

If it is much more than this you have a precise record of the Battery condition.   I did just that and my dealer changed the Battery with out even questioning me.

[RickyC]

On 8/10/2023 at 12:17 PM, TonyHSD said:

Perhaps that’s all it needs and your battery is in good health. 
 

Maybe, but it's a strange behaviour. 

If the integrated smart charger considers that Battery charge is OK,  why applies charge ( around 14 V ) with gear in D and removes when car is in P ?

If Toyota advice is to leave the car in READY for at least 30 minutes a week,  probably 30 minutes of parked car ( car left in P )  are less effective than 30 minutes of drive.

That's is contray to the expected logic, due to the indipendence from an alternator that could change its performance according to ICE rotational speed.

It could be interesting to record the voltage in 30 minutes of stationary parking and 30 minutes of drive.

[CruxisCore]

@Dala, we need your graphs on stationary charging 😁

[CruxisCore]

The Battery is probably beyond saving If its flat twice in a few weeks. Ofc give it a proper charge and see if it helps but it has almost certainly already permanently Lost some of its (already Limited) capacity

[Dala]

stationary parking 60 minutes

 

[TonyHSD]

Guys, you are thinking of a bit too much. 
Thete is no difference between driving or stationary. The alternator will provide constant voltage no matter of engine rpm. 
The dc to dc converter in Toyota hybrids too. The voltage fluctuation will depend on Battery soc and 12v system load. And my old car does behave exactly as your . Just coming in from troubleshooting a possible  12v Battery issue for a first time after 13 years & 249000 miles. 
Once the 12v Battery is dead is dead. 
Why yours in a new cars goes bang so quickly is another matter. Most likely connected services drainage  while car asleep, too many automated auxiliaries, additional cameras or gps devices, a lots of ECU’s, the DCM issues, a bad batches battery from suppliers, neglect by dealers while cars in transit and on PDI , lack of use by the owners. , or perhaps a combination of all above. 

[Roy124]

Core, that's why I said gather evidence then try and get a free,  or at least subsidised replacement. 

Of Phillipe bought it recently he has a better chance of a dealer replacement.

 

[Susan Shaw]

I have had the same problem on the Toyota Yaris Cross I bought in Nov 2022.  It has failed to start three times now after leaving it unused for a week.  Toyota have suggested a fit a solar panel to my windscreen at my own expense - so that I don;t need to use jump leads.  I am not happy with this response and believe it is a design fault.  Possibly the security system with this flashing dashboard light is draining the Battery - my best guess!  Talking to Toyota tomorrow again.  

[CruxisCore]

Have you had it properly charged since or is it just jump and go?

It'd probably be smart to actually hook it up to a mains charger for the night or whatever if it runs flat, still a chance to save it from a one-off flat Battery

[FROSTYBALLS]

Similar topics merged.

[Derek.w]

If using the car stationary just to charge the Battery I do not have the time to do that at least with a mains Battery charger I can lock the car up then go back after 4 or 5 hours and its fully charged.

[MCatPG]

This morning a van drew up beside me in a car park and the passenger introduced himself as working for a Toyota dealer. He asked how I was getting on with our car. I said OK but when is Toyota going to come up with a permanent fix for the 12V auxilary Battery problems? His response was to describe the problem from the dealers' perspective (short version: they are fed up with it). He mentioned getting a bigger Battery but I said the underlyng problems are the charging logic, including the lack of charge when in READY+P instead of READY+D, and the parasitic drains. He said the latter is the biggest problem because, wait for it, there are 52 ECUs in the car, all taking their own tiny little bit of current. 52 of the little blighters! I said that's madness and he agreed. But obviously that's something we are stuck with. My final remark was that all the hybrid manufacturers should be fitting charging points and telling customers that they need to provide an external charge to maintain their 12V auxilary batteries in good condition, and he agreed with that. However it's never going to happen and so perhaps this thread will live on for many years into the future. 

[Max_Headroom]

20 minutes ago, MCatPG said:

so perhaps this thread will live on for many years into the future.

It doesn't need to simply drive the car every few days or leave it in "Ready" when you are sat in the car at the supermarket etc waiting for your partner to do the shop, what better way to get out of doing that awful weekly trudge round the stores!

If i originally had no intention of buying a hybrid i would buy one for this reason alone 😉