12v battery problem

[Catlover]

Goes to show that tips you read on this forum are good ones.
Particularly with hybrids the 12v Battery system is lower powered then for a petrol car, and definitely a lot less power then a diesel car. If a Battery is getting weak (due to age maybe) a late spring frost (like this morning in west Cheshire’ could kill it. 

[TonyHSD]

This tips apply not only for hybrids and electric but for all types of vehicles. Any car left without use for extended period of time will have dead Battery and recharge or replacement will require. The older the car the greater the risk is. 30 min idle once a week will prevent all the trouble. The pollution and fuel waste will be minimal in comparison with many new batteries replacement, plus the inconvenience you can’t have your car when you need it. 
Regards 

[Ron in AR]

This is ridiculous. I have a 2013 Ford Edge I can leave at the airport for a month that starts without a problem when I return. There is no reason Toyota can’t do the same. The computer settings can be saved to a solid state drive and then the systems, except keyless entry, alarm, etc. can be shut off. My 2020 gas only Camry should not need to be charged every 2-3 days!  This is a terrible design defect!

[Catlover]

2 hours ago, Ron in AR said:

This is ridiculous. I have a 2013 Ford Edge I can leave at the airport for a month that starts without a problem when I return. There is no reason Toyota can’t do the same. The computer settings can be saved to a solid state drive and then the systems, except keyless entry, alarm, etc. can be shut off. My 2020 gas only Camry should not need to be charged every 2-3 days!  This is a terrible design defect!

Hi Ron, I forgot who suggested charging every 2 - 3 days.

[Gerg]

2 hours ago, Catlover said:

Hi Ron, I forgot who suggested charging every 2 - 3 days.

Joe, I think there is an ongoing problem with the latest hybrid Camrys (although he does mention "gas only") where the 12v Battery is going flat in a ridiculously short time.  'Ron in AR' is probably referring to that, rather than the 'normal' discharging of the other Toyota hybrid 12v batteries when the car is sitting unused for a few weeks or more.

[QuantumFireball]

Toyota Ireland are recommending to run hybrids for 30 minutes every 15-20 days:

https://twitter.com/toyotaireland/status/1245381049766612993?s=20

I would agree "every few days" is overkill.

I saw one of my neighbours jump starting their normal diesel ICE car yesterday - this issue is not exclusive to hybrids. 

[Children's Writerman]

The tip to run every few days is good advice but the suggestion of applying it to all vehicle types doesn't work. I know this is a Prius forum but we have been straying into Battery electric vehicle territor recently. There is no concept of idling with a BEV. Either the car is moving or it's not. I can only speak for Teslas. A Tesla continuously monitors the state of the 12v Battery and recharges from the automotive Battery as required. Tesla's advice is to leave your vehicle permanently plugged in when not in use. It will then maintain the health of both batteries. If you have another make of BEV, I would recommend checking your user manual or an appropriate online forum.

[Chris Dance]

My sons gen 3 Prius Battery. lasted 7 years. He does long journeys some across France to the Alps. 

My Gen 4 Battery lasted 3 years. problem is as an "oldie" our car does only about 3,000 miles a year and most of that for short distances. 

[Harters]

I used to have a Zoe and if that wasn't used for a few days in the winter it would always throw up error messages and a big red spanner saying maintenance required, but all that was needed was a quick whiz around the block and it would be sorted.  We did however eventually need a new 12V Battery at the two year service as we were advised it was on its last legs.  I had no reason do doubt that as it was giving the fault more and more frequently.

With the Zoe, like the Prius, as long as the car was in ready mode it would give charge to the 12V Battery from the main traction Battery and if I remember correctly it would charge the 12V battery once it had finished charging and balancing the main traction battery.

My Prius started OK the other day and that had been nearly 3 weeks with out any problem.

[QuantumFireball]

Yeah, the short journeys aren't enough to get a good charge on the 12V Battery. The only journeys I'm taking in the car now are to the supermarket every two weeks or so, and that's about a 3 mile round trip so not good enough. I think Toyota Ireland's guideline of half an hour every 15-20 days is a good one.

[PeteB]

My first Gen 1 Prius (a 2000 model) needed a new Battery at 18 months old (not sure if it had already had a previous replacement, it was an ex-demonstrator).

The original Prius had lots of Battery replacements because:

1. it had a small, 35 aH 12V Battery
2. it had a surprisingly high parasitic drain when off/locked
3. it sold very slowly (no advertising, only 60 dealers could sell/service them)
4. battery was flattened during sea journey (I believe later, once the issue was understood, shipping occurred with the battery disconnected)
5. battery was often flattened at least once during it's time on the dealers premises before sale.

I believe the 12V battery was small because:

• it didn't need to crank an engine - just fire up the computers, activate 2 relays that connected/disconnect the HV battery to the Hybrid system, run a few electric pumps to pressurise the braking system etc and the usual lights and door lock operations.
• everything on the Prius design was aimed at minimising fuel consumption and emissions, such as low rolling resistance tyres, good aerodynamics and keeping weight as low as possible - hence a smaller, lighter 12V battery.

Later models got slightly higher capacity 12V batteries and reduced parasitic drain, but the reason Hybrids get a lot of comments about 12V batteries is that they are generally lower capacity than equivalent petrol/diesel cars.  True, any car can be affected by low/no use, but it will likely afflict the Hybrids sooner.

My last Gen 4 2016 Prius needed a new 12V battery at 18 months old, but i'm not sure if it had been mistreated before delivery or was a faulty one.

[PeteB]

2 minutes ago, QuantumFireball said:

...I think Toyota Ireland's guideline of half an hour every 15-20 days is a good one.

Sounds sensible.  I've practised sitting in the car in READY mode for ½ hour every 10 days or so in mine when they've not been used, just to be sure, and it's certainly avoided any problems.

[PeteB]

6 minutes ago, PeteB said:

My first Gen 1 Prius (a 2000 model) needed a new batter at 18 months old...
...My last Gen 4 2016 Prius needed a new 12V battery at 18 months old

 

I meant to add that my second Gen 1 Prius, a 2002 model, had a new 12V Battery at 2 months old, but the replacement was still in the car when I sold it 9 years and 160,000 miles later!

[kithmo]

8 hours ago, Ron in AR said:

This is ridiculous. I have a 2013 Ford Edge I can leave at the airport for a month that starts without a problem when I return. There is no reason Toyota can’t do the same. The computer settings can be saved to a solid state drive and then the systems, except keyless entry, alarm, etc. can be shut off. My 2020 gas only Camry should not need to be charged every 2-3 days!  This is a terrible design defect!

AFAIK there are no "computer settings" lost when you disconnect or flatten the 12v on the Prius, the only thing lost is the electric window auto up and auto down limits, which takes you about 20 seconds to re-apply.

[FROSTYBALLS]

Also see 

 

[QuantumFireball]

Interesting that Toyota GB's advice is quite different compared to Toyota Ireland. I think one hour of running every week seems a bit like overkill - I've left my car for over two weeks on previous occasions (garaged) and it's been fine. Though I do understand earlier Gen 3's with keyless entry had problems with parasitic drain, and certain other models aren't great in this respect either.

I wonder if only letting them idle through the warmup/charging phases while parked could lead to condensation forming in the engine? I don't know if the engines in hybrids are designed in some way to combat that due to their lower expected duty cycle. I used to get a bit of mayonnaise-like substance under the oil filler cap in my Mk. 4 Fiesta if I was only doing short trips, but that pushrod engine was truly ancient in design...

[LLEWELLYN]

I have a permanent charger fitted in the prius 2007 that keeps the Battery charged only use the car once a week by having the charger on never let me down and main Battery never lost any charge Once left the charge off for a couple of days and the main Battery also lost some charge.  Have a AGM battery at least 6 years old it does need changing Do I need to fit a AGM battery or will a normal one be OK

[Ancient Nerd]

Your Prius has the Battery in the boot, which is really part of the passenger compartment. A conventional Battery will work fine until you have an accident and the Battery is damaged. A conventional battery will result in you sharing the compartment with the liquid battery acid. The AGM battery (afaik) is a gel type that doesn't have this problem, so is much safer. 

The gen 4, and gen 2 plugin, both have the battery in the conventional position in the engine compartment, so this is no longer a problem. 

Edit: My apologies if this is a bit out of time or context. I clicked on the next unread topic, and I got taken to the original post. So my answer above is to the original post, a week and many other responses later.

[Mick F]

11 hours ago, Ancient Nerd said:

Your Prius has the battery in the boot, which is really part of the passenger compartment. A conventional battery will work fine until you have an accident and the battery is damaged. A conventional battery will result in you sharing the compartment with the liquid battery acid.

Some of us are old enough to have owned a Mini or two.

My first was a 1968 Mini Van, and over the years I've owned eight Minis ranging from vans and estates to saloons.  Two saloons were brand new.

The Battery in the vans and the estates is behind the driver's seat, and in the saloons it's in the boot.

As far as I know, there's never been an issue with Minis in crashes with Battery acid.  Correct me if I'm wrong.

Mick.

[TonyHSD]

1 hour ago, Mick F said:

Some of us are old enough to have owned a Mini or two.

My first was a 1968 Mini Van, and over the years I've owned eight Minis ranging from vans and estates to saloons.  Two saloons were brand new.

The battery in the vans and the estates is behind the driver's seat, and in the saloons it's in the boot.

As far as I know, there's never been an issue with Minis in crashes with battery acid.  Correct me if I'm wrong.

Mick.

Hi Mick,

The Prius /Auris hybrids 12V Battery is located rear right corner in the boot, even a small impact at fairly  low speed may cause a damage to the Battery, this is most likely the reason for that specific type Battery Toyota uses. If battery is located inside the interior far away from any corners of the car that might be different, and also I am not sure what type of batteries were available back in the days. 
 

For the cars that are not in use now, as older the car (battery) is the higher the risk is to have it flattened, for hybrids once a week 30 min idle will be fine, you can leave longer but then you need to keep it idle longer or drive it, and here is the biggest difference when you leave your car at airport for three weeks holiday and you are back, the car starts as usual but then you drive it as usual. If you leave it now for three weeks then only 30 min idle or use will be ok but after another 3 weeks and another 3 weeks if the battery is old may well get flat and will need proper recharging or replacement. 

For standard cars large engine or diesels not good to keep playing with the car if you don’t drive it just start once a week and let it idle for 30 min, if you don’t use the car don’t start and stop more often then that , this may have negative effect because larger engines and diesels need more Ah to crank the engine therefore needs more time idle to get a good amount of charge. All those processes of car battery discharge are accelerated in colder temperatures and where batteries are old and not at their max capacity. 
 

Regards 

[Mick F]

The batteries in the older days were lead-acid with individual cells that you kept topped up with distilled water.  The caps were variously little screw-tops, a three-cell lift-off cap, or a six-cell cap.  The batteries had to kept the correct way up or the acid leak out via the breather holes. Later cars had a semi-sealed top, but they were still lead-acid and still had to be kept the right way up.

These days, you'd struggle to find a non-sealed 12v Battery.  Probably all gell-based too AGM or otherwise and all sealed for life.

Mick.

 

[Children's Writerman]

52 minutes ago, Mick F said:

The batteries in the older days were lead-acid with individual cells that you kept topped up with distilled water.  The caps were variously little screw-tops, a three-cell lift-off cap, or a six-cell cap.  The batteries had to kept the correct way up or the acid leak out via the breather holes.

 

You're bringing back memories, looking for distilled water to top up the Battery. 

[Catlover]

3 hours ago, Mick F said:

Some of us are old enough to have owned a Mini or two.

My first was a 1968 Mini Van, and over the years I've owned eight Minis ranging from vans and estates to saloons.  Two saloons were brand new.

The battery in the vans and the estates is behind the driver's seat, and in the saloons it's in the boot.

As far as I know, there's never been an issue with Minis in crashes with battery acid.  Correct me if I'm wrong.

Mick.

But it only takes one to burst in a crash and occupant(s) could be scared for life. In todays world a car manufacturer who was "careless" enough not to plan for all eventualities could be sued for tens of thousands, maybe 100's.

[TonyHSD]

My previous car Mitsubishi Lancer a proper old school car despite build in 2007 had a non sealed Battery that needed some top up from time to time, I bought the car used 9 years old with only 42k miles then two years later sold it at 133k with its original Battery, there were no signs of aged Battery at all. Proper Japanese machine. Miss that car so much. 👍

[PeteB]

58 minutes ago, Catlover said:

...In todays world a car manufacturer who was "careless" enough not to plan for all eventualities could be sued for tens of thousands, maybe 100's.

or in America ...  millions!