12v battery maintenance, issues, etc.

[jthspace]

17 minutes ago, Roy124 said:

Jeff. I was suggesting the potential for an income stream.  Perhaps sell it to Toyota etc .

😁 well I worked for over 50 years and really enjoy my retirement. I've got 2 MX5's to take out on club runs and meets which keeps us out and about.  Then the fettling on them, I'm always fiddling with something.  Oh, and breakfast club, trips up to Norfolk coast...... you get the idea.

That being said, neither MX5 has been out since we got the Yaris, it's my first choice at the moment; even managed over 80 MPG on an ECO run out to lunch with some friends, 20 Miles each way on the A11/A14. Amazing.

I'm sure Toyota know all about the perceived/real Battery  issue and that they hear from their customers as well as reading the posts on here.  Judging on their manufacturing down to a cost, spending £10 when they make the car would probably be a no-no. Also the £75 they would charge for the Battery charger accessory (net cost £15) would generate more moaning about the cost of add-ons.  Then the "we need this" vs "just drive it"  discussions would fill another 50 pages of comments!  

That being said, I have a friend who manufactures MX5 enhancements and I'll pass this to him to see if he would be interested in putting a kit together. I'll report back. 

BTW, I think this (12v Battery thoughts) particular part of the site has been most entertaining and one of my favourites.

Jeff

[CruxisCore]

11 hours ago, Derek.w said:

As part of the service I expect it to be returned fully charged!. NOT to imply take it home and recharge it yourself its a lot more polite as part of a service to say we recharged it and you need to keep a eye on it by giving it a charge once o month.

Amber condition I presume it refers to a load test and the time it takes for the battery to recover.

If so then it was probably recharged afterwards but a lot of info lost in customer service department went its handed back to you.

Regular service is a 1-2h thing at best. A Battery that actually needs charging really does need that overnight charge, those few hours won't do a whole lot to it.

[Roy124]

Just done a quick and dirty analysis of my Battery voltage starting on Monday morning before the car was serviced.  

The start voltage in the garage was 12.35v.  It is still 12.35v this morning.

When the car was taken to the garage the voltage jumped to 14.46v and settled to 12.42v.  During the servicing period the voltage varied but each time the car was clearly not in Ready mode the voltage dropped but by 5pm was at 12.51v before it was returned to me.  By midnight it was 12.46v.  In other words the two short drives and other periods which came to exactly 60 minutes gave a 0.11v boost.

Then followed 77 minutes on the 18th, 54 minutes on the 19th, and nothing since then.

At midnight on the 18th the voltage was 12.49v.

At midnight on the 19th it was 12.46v

The 20th have 12.38v and the 21st 12.36v.

We had one drive on the 16th, 3hr 52min and the start voltage had been 12.37v and the voltage at midnight was 12.55v.  

It suggests that even 4 hours in Ready mode does not give a large increase on voltage and after 2 hours in Ready mode in the week the resting voltage is back near 12.37v.

I know from previous use with the CTEK charger that the 'stop' voltage is nearer 12.7v or almost 0.3v higher than the DC-DC charge delivers.

[CruxisCore]

It does certainly seem like that the car's software is fine with the Battery hanging around 12,3-12,5. It doesnt seem to push very hard to get it above that and only seems to really activate when it seems to go below that 12,3v threshold.

Hard to say whether or not that is just some magic number Toyota has decided on as a compromise for best efficiency or whether it's due to the DC-DC converter not being able to charge a CaCa Battery to maximum voltage (remember, it takes over 16v to fully charge a CaCa battery).

But the 12,3v is interesting. We're still talking about 70%ish state of charge (while 12,5v is 90%ish). But still, at that amount of passive bleed you are rather soon in dangerous waters if/when the car truely isn't gunning for 12,7V 100% charge. 

 

[Roy124]

28 minutes ago, CruxisCore said:

It does certainly seem like that the car's software is fine with the battery hanging around 12,3-12,5. ....

Hard to say whether or not that is just some magic number Toyota has decided on as a compromise for best efficiency or whether it's due to the DC-DC converter not being able to charge a CaCa battery to maximum voltage (remember, it takes over 16v to fully charge a CaCa battery).  ℹ️

But the 12,3v is interesting. .... But still, at that amount of passive bleed you are rather soon in dangerous waters.....

 

From previous detailed monitoring I got a daily drop of 0.01v.  Ten days would be 0.1 and even 3 weeks only 0.2v though I have not tested it over 3 weeks.

The car is now sitting on the charger at 14.46v.

Interesting what you say about the CaCa charge.  I did ask CTEK and they referred me to Toyota.  I think the answer was use Lead-Acid setting.

[jthspace]

13 hours ago, Roy124 said:

Jeff. I was suggesting the potential for an income stream.  Perhaps sell it to Toyota etc .

Hi Roy,

My friend and I have discussed the pros and cons of offering a kit. As you can imagine, it's not as straight forward as one might think.

Looking through AliExpress both the sockets and voltmeters are available for around £3 each. I'd also want to add in a hole saw. Could put everything together in a suitable box for about £10.00. However we would have to order 10+ of everything in anticipation of orders.

Selling on eBay there are the fees to consider and posting would be at the small parcel rate. Selling at say £20 would give around £6 profit. Under a fiver after income tax!

Here's the thing that would limit sales. Many people are very wary of drilling into their car never mind about doing anything electrical. From other kits my friend sells, it doesn't matter how clear you make instructions some don't read them and some can't understand them. Some then leave negative feedback and on eBay, that's a real curse.

I think I'll just leave it as a "how to" and I've copied it into the How To guides section as well.

ATB, Jeff

[Roy124]

11 minutes ago, jthspace said:

Many people are very wary of drilling into their car never mind about doing anything electrical.

Many many years ago I bought a reversing light kit from Triumph for my 1300.  I don't know how I got under the car, ramps maybe, and drilled a hole in the gearbox to mount the switch.

I shudder now to think about it. 🥴

I also did 'mad' things like changing ignition to contactless, adjusting timing, dismantling and reassembling a windscreen wiper stalk (needed Araldite and locking wire to replace the drilled out rivets), fitted relays for the headlights and fog lights, and refitted a cruise control from car to car.  The last iteration the garage said couldn't be done; I did it.

[Roker]

I am just in the process of buying a 2020 corolla and new to this forum, I am alarmed about the Battery issues I have read on here.

All cars even none Hybrid there is a sacrificial current trickling from the Battery to computers essentials camera anti theft etc and when the car is shut off.

Why can't there be a power pack powered to switched from the main Battery to the 12 v system to give the engine a start in emergency

[Mojo1010]

Don't be alarmed as that will drain the Battery even more! 🙂

Very few people have the Battery problem, some people inherited a below par Battery from previous owner/garage. Or very short trips/low usage. Use the car regularly or put it in ready mode for 30 mins or so a week - that you would have also read.

Most people don't have this problem. Had my Yaris for 5 years (7yrs old) not a single issue with 12v battery. I do not have anything like solar/jumper start/ or charger. You posted on the Yaris forum, no harm done. 

 

[Xerapin]

Well, Amazon delivered my cigarette socket voltmeter charge effort today. Interesting phenomenon.

Car on accessory Mode it reads 12.0~12.2V
Car on Engine Mode (I drove it this morning, so the EV was on, not the petrol engine) it reads 14.0 V

Does the Battery get a bit of a boost when the engine is running? All looks good to me though, and thats a week of short trips to the doggo park, with the last meaty trip on Tuesday (150miles round trip).

[CruxisCore]

 

22 minutes ago, Xerapin said:

Well, Amazon delivered my cigarette socket voltmeter charge effort today. Interesting phenomenon.

Car on accessory Mode it reads 12.0~12.2V
Car on Engine Mode (I drove it this morning, so the EV was on, not the petrol engine) it reads 14.0 V

Does the battery get a bit of a boost when the engine is running? All looks good to me though, and thats a week of short trips to the doggo park, with the last meaty trip on Tuesday (150miles round trip).

 

Be wary of the accessory mode. That will probably lead to a flat Battery easiest and surprisingly fast. 12-12,2v is normal cos Acc mode uses Battery but has no way of regaining it.

In Ready mode 14v is a rather normal voltage that shows the car is actively charging the Battery. It doesnt have inherently anything to do with EV mode or car using the combustion engine, rather the car's brain literally decided that battery voltage is now low enough, lets charge it up some. There is apparently at least a more light "trickle charge" mode as well as a heavier form of charging, but probably also something in between, as this isnt the highest voltage I've seen when charging, but the trickle mode is more in the the 13s range. Might wanna check later after the car has "cooled off" to see what the voltage says at that point, as that 14v is cleary when it's charging rather than that the battery is resting at 14v.

But yeah, the conclusion you can make from some of the graphs people have posted here is that the car does whatever it wants and sometimes it's hard to find a logic in it. 

But yeah, I'd say avoid accessory mode and just keep the car in ready mode if you are waiting in the car.

 

3 hours ago, Roy124 said:

From previous detailed monitoring I got a daily drop of 0.01v.  Ten days would be 0.1 and even 3 weeks only 0.2v though I have not tested it over 3 weeks.

The car is now sitting on the charger at 14.46v.

Interesting what you say about the CaCa charge.  I did ask CTEK and they referred me to Toyota.  I think the answer was use Lead-Acid setting.

 

I would definitely not push more than 16v at least while the battery is connceted. It does seem that CTEK Recond mode (pushes up to 15,8v or so) is safe, but at your own risk if you decide to try it. But according to what is known about these CaCa batteries, they will never reach full SoC with regular 12v charging voltages. They've probably accounted for it, but again the problem can rise with certain kind of use.

[Graham47]

35 minutes ago, Xerapin said:

and thats a week of short trips to the doggo park,

@Xerapin….just out of interest…what sort of mpg does it record for these ‘doggo park’ trips ?

[Xerapin]

28 minutes ago, Graham47 said:

@Xerapin….just out of interest…what sort of mpg does it record for these ‘doggo park’ trips ?

It really depends on the traffic, the worst I've seen is 42.4MPG when I got caught during the school run. The best I've seen which was from the house to the park (Downhill) of 68.2MPG, but I would say it averages around 55MPG as its 1.5miles away, so for the first .5 miles the petrol engine is usually warming up before the EV settles in.

[Derek.w]

I seldom use acc mode but its gives you a idear of the car Battery with gage pluged into cigaret lighter socket but voltage reading will always be slightly higher than what it reads because you are reading Battery voltage under a load condition.

My BM monitor is reading 12.33 volts. but in acc mode its reading is 11.9 volts the diffrance is some power is now deen drawing off.

[Derek.w]

6 hours ago, CruxisCore said:

Regular service is a 1-2h thing at best. A battery that actually needs charging really does need that overnight charge, those few hours won't do a whole lot to it.

A garage can recharge a Yaris Battery at upto 15 Amps max that info is in the handbook under Vehicle Specifcations page 182.

[Max_Headroom]

How far will the hybrid travel in electric only mode if the Battery is full, is there a maximum speed before the ICE kicks in?

[Roy124]

41 minutes ago, Max_Headroom said:

How far will the hybrid travel in electric only mode if the battery is full, is there a maximum speed before the ICE kicks in?

Not very and yes.

You are unlikely to see a full Battery.  At best there always one bar, maybe 2, uncharged and discharged below 4 is unlikely.

Downhill, with a gentle foot, you might achieve a mile.   Once at speed,  say upto about 60 and level to a gentle slope, maybe a couple of miles.

As soon as you apply power the car will probably fire up the ICE. Speed is not really the relevant factor.

A 1,200 yard trip was on EV for 1 000 yards and 80% of time. The ICE was used to move the car up about 20 feet in 100 yards and then a further 15 feet and accelerate to 25mph over about 50 yards.

This was a cold start and showed mpg of 38mph.

 

[Roy124]

A philosophical question:

If a car achieves 70mpg on a journey and EV for 50% of the distance, what mpg would it achieve if the EV was not a factor?  Would it be around 35mpg?

[Graham47]

1 hour ago, Max_Headroom said:

How far will the hybrid travel in electric only mode if the battery is full, is there a maximum speed before the ICE kicks in?

I think this is my best so far …..

Start from cold (ICE for short reverse up drive) then EV, downhill, (very gentle) uphill on EV, gentle flat at 40 mph on expressway into town.  Final 0.3 mile was all slightly uphill into car park.  But for traffic I think I might have been more gentle and achieved even 100% EV !

[jthspace]

My Yaris on A road to breakfast/Aldi shop today (Sunday) and B and single track country roads back averaged 68mpg and I discovered at 48 mph it stayed on Battery most of the time. Luckily no other cars at all so 48 on a 60 road didn't pee anyone off.  Mind you, I could buy a flat cap and then it gives me permission to do that anytime 🤣😂

[jthspace]

1 hour ago, Roy124 said:

A philosophical question:

If a car achieves 70mpg on a journey and EV for 50% of the distance, what mpg would it achieve if the EV was not a factor?  Would it be around 35mpg?

Seems a reasonable thought.  Same rolling resistance etc. But the engine I expect will be working harder as no assistance from the Battery. 3 cyl 1.5L isn't designed to run "petrol only" though and was designed as a generator.  CVT helps in mitigation.

My 2L 190bhp MX5 returns low 40's on E5, mid 30's on E10 even driven "to enjoy" rather than frugal. I've seen 51mpg average on a ride-out in a group of 5 cars.

[TonyHSD]

Toyota full hybrids aren’t to be mistaken with plug in hybrids or bev. They don’t have an ev range at all.  
You can top up your hybrid Battery easily if you go downhill, 2 miles downhill even without pressing onto the brakes a lot and your Battery likely to get filled up full.
The range you can get after that in pure ev if you select ev button is max 1 mile if you drive slowly up to around 30mph and of course accelerate smoothly, otherwise the car will flip to its hybrid mode immediately. 
The ev button is very helpful for example if you like to move the car from one parking spot to another or similar circumstances, start the car to top up your tyres with 12v air compressor and you need to have enough juice in the Battery plus switch off hvac. 

One tip for those who does these dog walks ultra short trips, to get maximum efficiency best to turn off hvac completely for these journeys and crack open the windows for refreshed air. 
If hvac is off there won’t be need of heat , engine needs very little warm up to work safely, just to move the oil around inside engine and transmission, no ac ON also means no high voltage drain and you can glide in ev mostly. 👌

[TonyHSD]

1 hour ago, Roy124 said:

A philosophical question:

If a car achieves 70mpg on a journey and EV for 50% of the distance, what mpg would it achieve if the EV was not a factor?  Would it be around 35mpg?

No, it won’t be 35mpg, more like 50-55mpg I would say.  
You can’t remove the ev factor from the total power in Toyota hybrids because how they had been designed to work.. But to understand how efficient are these engines you can take an example to compare with Yaris mk4 1.5 petrol non hybrid either auto cvt or manual, cars that sadly haven’t been offered here in uk but available on other markets and these cars are doing exactly that, they run on pure petrol , use the same engine with slight modifications and delivery also great efficiency, there are data sheets available on Toyota website to compare. Here a quick look . https://www.toyota.bg/new-cars/yaris/build?path=engine/09a6531a-c3f1-4d2d-b4d3-eb45cbb35478/7b77d85b-8f26-4645-82ac-22154a7d6293/794e7377-29d0-42fb-b62e-253fbf6c9c8a

[Dezzer21]

Tried my bm monitor this morning showing 12v in acc mode in ready mode 14.1 sat in car an hour in reading manual car fired up twice for a minute or so, hopefully Battery ok.

[Cyker]

1 hour ago, Roy124 said:

A philosophical question:

If a car achieves 70mpg on a journey and EV for 50% of the distance, what mpg would it achieve if the EV was not a factor?  Would it be around 35mpg?

As others have said it's not as simple as that - The thing is, with the normal non-plugin hybrids, all the energy comes from the petrol and the engine. I would guess in a similar ballpark to Tony - 50-60mpg maybe, but very dependant on the journey (Urban/motorway, smooth/stop-start etc.).

The super clever thing about the hybrid bit is it's like a turbocharger - It captures energy that would be wasted, and that's where the efficiency boost comes from.

The M15A-FXE is rated for a peak efficiency of 41%, but that's only at a certain RPM and load - At 6000rpm it definitely *isn't* 41% efficient  but around 2000rpm seems to be the sweet spot.

That's why the engine will run at weird RPMs at a given speed (e.g. mine will run at around 2000rpm at almost all speeds if I'm only driving gently, anything from 70mph to 5mph!).

Driving at 2000rpm at 5mph would be very wasteful normally, even tho' that's the most efficient RPM, but what the hybrid system can do is take all that wasted energy and stuff it into the Battery for use later.

Unlike normal cars, where the engine is running at 3%, 5%, 10%, 20%, 30%, 5%, 20%, 5% etc. efficiency as you're accelerating/decelerating, going up and down hills, revs constantly going up and down etc., the hybrids can run at near 40% *all the time*.

That's where most of the efficiency comes from and not, say, brake regen, like a lot of the automotive press are convinced of (Brake regen actually regains surprisingly little energy in the grand scheme of things!)

That's also why diesels get such good mpg, as across their whole rev range they can stay in a 30-40% efficiency band, whereas petrol has much lower dips under e.g. hard acceleration and high rpm.

 

2 hours ago, Max_Headroom said:

How far will the hybrid travel in electric only mode if the battery is full, is there a maximum speed before the ICE kicks in?

 

TBH not very far - It only has 0.7kWh of capacity and that runs down quick, esp. at speed! It makes the EV mode button pretty pointless in the Mk4s!  On the very very very rare occasion I've gotten it to work (As opposed it saying I'm going to fast or there not being enough charge), I think I got 200-300 metres in traffic before it cut off again!  

There isn't really a maximum speed tho' - The car can run on electric-only well over 70mph, thanks to that reduction gear they added, but only if there is very little load being put on the motors. As soon as you put any significant load on to e.g. accelerate, the ICE will usually kick in as it can provide a lot more torque than MG2, thanks to MG1 faking gear ratios.