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12v battery maintenance, issues, etc.


FROSTYBALLS
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23 hours ago, Max_Headroom said:

How long does it take to recharge the battery from 25% by driving the car. 

As no one answered why not take the car for a short drive every 3 days if it goes flat after 5 or trade it for a non hybrid if you are doing so few miles. 

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For periods longer than a week, can't the Battery be disconnected?

i think there is a switch under the hood  that disconnects the 12v Battery.

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For sure there are several workarounds. But, we're just trying to accommodate for something that clearly appears to be a design flaw.  

Leaving a car unused for up to one month, should not be a problem, providing you have a healthy Battery. We have done this multiple times, with Toyota hybrids too. 

Beyond this period, then yes, even older cars may have trouble getting going again, depending on weather. 

Two weeks is perfectly reasonable to expect without doing anything extra. It's a normal holiday away, or just a quiet time. I'd complain to Toyota and possibly swap the car for something else if your usage pattern repeatedly leaves a flat Battery. It's stress you could do without.

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On 9/23/2022 at 6:29 AM, Max_Headroom said:

How long does it take to recharge the battery from 25% by driving the car. 

Probably a lot longer than you think. If the Battery is 100% healthy and the voltage limited to around 14 volts (and it will be current limited as well) then I would estimate around 8 hours or more. As the charge increases the current falls away and so it takes a lot lot longer to put that last 10% back.

If the Battery is deteriorated then it will take longer still and you will have a lower overall capacity even when it appears fully charged.

On 9/22/2022 at 9:29 PM, Roy124 said:

I think the hybrid battery is a number of small cells arranged in series. A smaller number could be connected to provide a 12v source that could activate the system. 

A good idea in theory but may be problematic in practice. Draining some cells in a series chain makes managing and equalising charge on all the cells much more difficult. The cells in a high voltage Battery are also surprisingly small in capacity, only a few Ah, far far less than the cells in the 12v battery. 

It would also require that the hybrid battery is 'referenced' to ground (chassis, zero volts) which it may well be but isn't necessarily a requirement given the invertor technology.

The real answer to all these issues is better battery management and crucially better management of background consumers of power.

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2 hours ago, Mooly said:

Probably a lot longer than you think. If the battery is 100% healthy and the voltage limited to around 14 volts (and it will be current limited as well) then I would estimate around 8 hours or more. As the charge increases the current falls away and so it takes a lot lot longer to put that last 10% back.

Thats shocking they really do need to have a look at this problem if it becomes well known they are going to lose sales.

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Max, trouble is I think the volume of problems only occurred in 2020 with Covid lock down.  Their Ready Mode advice probably reduced many instances (complaints) and work around such as Battery packs and solar chargers reduced complaints even more. 

Now if the motoring press picked this up and caused widespread criticism of Toyota then maybe they would be moved to get out a fix. 

Just a thought, dies BZ4X have an auxiliary Battery

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1 hour ago, Roy124 said:

Max, trouble is I think the volume of problems only occurred in 2020 with Covid lock down.  Their Ready Mode advice probably reduced many instances (complaints) and work around such as battery packs and solar chargers reduced complaints even more. 

Now if the motoring press picked this up and caused widespread criticism of Toyota then maybe they would be moved to get out a fix. 

Just a thought, dies BZ4X have an auxiliary battery? 

What is “the volume of problems” ?
Is there any evidence (outside this forum) that there is a ‘significant’ problem ?
 

From time to time I look in on a Honda Jazz forum.  Not seeing any such issues with their new Hybrid model (and there are a number of ex-Toyota owners posting).

Similarly, nothing on HonestJohn.

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I've left my Mk4 for a bit over 2 weeks and it started no problems, so the problem isn't inherent to hybrids, but I use my one constantly during the week as part of my job (So much so that I have to service it roughly every 8-9 months to comply with the 1yr/10k mile requirement of the warranty! :crybaby:

I think the problem happens more if e.g. the Battery is old, and is especially likely to happen if the car isn't used much, and is then subsequently left for a long time.

That said Toyota should be aware of the problem as it's been a known issue for over 10 years - We had quite a few Auris hybrid owners complaining about it on these very forums back in the day - so it's a bit disappointing they still haven't come up with a solution.

I've suggested that they copy Hyundai's fix, which is quite clever - If the 12v depletes to a certain level, the car cuts off all 12v systems, and requires the owner to manually open the car, press a 12v Reset button, which then re-activates the Battery for a short time, enough for the owner to start the car. It stops the 12v depleting to the point where 'jump-starting' is required and I thought it quite a clever bodge in lieu of something better.

Some newer EVs can also automatically engage the traction batter contactors to charge the Battery, although in the case of hybrids that might not be so useful given how small the hybrid batteries are and how dangerous it is to discharge the hybrid battery!

 

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I mentioned this problem to my Toyota dealer when my car went in for its first service. Their reply was it was not required to check the Battery as they think the cause was that I had only done 2,500 miles in a year. If the problem existed after regular daily driving they would have looked in to it. Plus they said that my Battery would not be covered by the warranty as they blamed the issue on low mileage. In my opinion a low  Battery state after 5 days of not using the car is pretty poor for reliability. Plus when the battery is low the brake pedal pulsates and one headlight comes on and all the electrics go crazy with a clicking noise coming from somewhere. Four jump starts now in a year and a half.... not good is it on a brand new car? Never had this issue on any non-hybrid car (bring back the alternator I say) in the 41 years I've been driving. Everyone should mention this problem to Toyota having experienced the problem or not. BTW.... the solar trickle charger has not made much differnce unless used on a really sunny day.

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If you are doing such a low milage (2500 anually) the Battery is not getting a full charge as discussed earlier so when you park it you may only have 40%  charge a s you leave it 5 days with stuff running in the background it's not a wonder it goes flar, can I ask why you chose to pay so much for a car that does lots of MPG when you hardly drive it?

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I'm not being funny, but if you only do 2.5k miles a year, why do you even have a car?? You have a 20-25 *thousand* pound vehicle, plus the tax and insurance costs!!

That's a lot of money to spend on something you're not really driving...

If it was a weekend toy then sure, but otherwise I feel it would make more sense to subscribe to a car club or something with such little use. Even using taxies would still be far cheaper in the long run with that sort of mileage!

You could buy a full solar panel and Battery setup twice over with the money you'd save!

Or a lot of pizzas... or a whole pizza chef! Mmm pizza...

(Sorry it's dinner time and I'm hungry and forgot to prepare anything...)

 

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44 minutes ago, Max_Headroom said:

If you are doing such a low milage (2500 anually) the battery is not getting a full charge as discussed earlier so when you park it you may only have 40%  charge a s you leave it 5 days with stuff running in the background it's not a wonder it goes flar, can I ask why you chose to pay so much for a car that does lots of MPG when you hardly drive it?

Sometimes I ask myself that very question Max,they say love is blind,I fell for the technology.

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Members have to bear in mind that people's needs vary, and really it is their choice as to how they spend their money.

Some require a car just for the convenience of having one, they may have a health issue, may not have easily accessible public transport, etc, etc.

Not everyone has a car club operating in their area.

For example one of our neighbours had a 59 (2010) reg Fiesta they bought from new. They had  covered 7,900 miles in it by the time they swapped it in 2016 for another new Fiesta. The 2016 Fiesta was recently stolen, and that had covered a similar mileage. They now have  Ka+.

So not everyone does 10,000 miles a year, etc.

People have different reasons for having a car.

Please return to the topic subject - '12v Battery maintenance'.

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TruBlu, sounds like your dealer didn't want the bother.   With several failures in its first year and my documenting the voltage loss my dealer changed the Battery with no argument.  Not only that they fitted a larger Battery

 

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I noticed it's a Dynamic  so it might be worth turning off the Smart/Keyless entry system when it's not going to be used for a while to see if that helps with the drain.

I think with such low mileage you're stuck with a trickle-charger tho' - Even Shmee150 has to trickle-charge his collection of super cars to stop the 12v's dying!!

There needs to be a bit more consistency in the Battery warranty coverage tho' as it doesn't look good if some people get a replacement and some don't despite similar circumstances. There's nothing in the warranty specifying a minimum miles driven for it to qualify AFAIK...?

 

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1 hour ago, FROSTYBALLS said:

Members have to bear in mind that people's needs vary, and really it is their choice as to how they spend their money.

I totally agree but wonder if Trueblue  had read this thread before buying the car he still would have.

The problem now is it's not going to go away due to the lack of milage so it's either a case of using a charger, drive the car more or change it for a non-hybrid.

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There are two ways that the Battery can be charged -

1) by using ready mode and charging the 12v Battery from the hybrid Battery as per the link at the start of this topic (though it wouldn't necessarily need a full hour as per Toyota's advice), or

2) by using a trickle or solar charger.depending on where the car is kept.

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That pretty much sums it up!

(Personally I recommend driving it more - The car is a total riot and should be driven at every available opportunity along interesting and scenic roads :biggrin: )

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51 minutes ago, Max_Headroom said:

……so it's either a case of using a charger, drive the car more or change it for a non-hybrid.

Why do you feel a non-hybrid would be any better with low usage ?
Surely the Battery would be depleted more with each start (starter motor load) but would still only be refreshed over a low mileage.

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Hi everybody I only driving about 2500 miles a year

I have it for convenience plus some cargo trips I do for my other hobby ie keeping pets.

At the end of the day you cannot take your money with you so may as well spend it..

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You can charge the car Battery by driving to a maximum of 80% capacity.
Smart charging can cause even a long car ride to charge the car Battery even less.
The capacity of the car Battery decreases rapidly with decreasing temperatures.
The normal amount of parasitic draw in newer cars is up to 85 milliamps = 14.3 amps/week
35 Ah + maximum 80% charge by driving + smart charging + low temperature in the morning + parasitic consumption + short trips = death of car battery in winter within 10 days without driving.
without regular recharging, it is impossible to keep these weak car batteries alive for a long time.
Just check the car battery voltage before driving in "ACCESSORY" mode and "IGNITION ON" with a voltage meter for the cigarette lighter socket in the car.

if the voltage is low - less than 11,4V - it's time for a car charger and recharge the car battery as soon as possible - eg CTEK.

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15 hours ago, Graham47 said:

Why do you feel a non-hybrid would be any better with low usage ?

I have never had a Battery regularly go flat in 5 days even when only doing short journeys i think this thread proves low milage and this type of hybrid do not work you shouldn't have to use a Battery charger on a nearly new car if only parking for 5 days.

BTW i am not knocking hybrids i would have one tomorrow as the amount i drive would mean i wouldn't have the flat Battery problem.

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57 minutes ago, Max_Headroom said:

I have never had a battery regularly go flat in 5 days even when only doing short journeys i think this thread proves low milage …….

Neither have I.

8800 miles in 4 years.

4 weeks plus 1 week in 2019

5 weeks (twice) in 2020

Often left for 3 days unused over weekends.

Don’t possess a charger any more nor do I use a solar charger.  (That’s like buying a crutch to ‘cure’ a broken leg.)

Very few of my journeys are longer than 15 minutes.

What am I (not) doing that (some) others are ?

I’m convinced that ‘something else’ is the cause that is significantly draining the batter even when the car is used.


As I said earlier …. this thread “proves” nothing.

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52 minutes ago, Graham47 said:

As I said earlier …. this thread “proves” nothing

It's 5 pages long if nothing else it proves some owners are having problems and others not.

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