12v battery maintenance, issues, etc.

[Roy124]

In our engine lectures many decades ago I recall the graphs with cross over points at about 40% and 60%. 

At 40% you got best gallons/hour or endurance.

At 60% you got the best balance of speed against consumption. This was range speed. 

At higher revs you would get more speed but less range.

Translating that to a car, if journey time was unimportant,  40% would save you fuel.  If time was more important,  60% would get you there sooner and use the optimum amount of fuel.

I wonder how that would translate to EV.

[Dala]

My the best 1.7l/100 km = 165 mpg.  

 

[CruxisCore]

It's a bit sad watching reviews where most of the reviewers are like "ooh EV only mode" just for it to deactivate 200 meters later. Yet they talk almost nothing about the actual hybrid stuff.

The EV-mode might be useful when coming home late and don't want to wake up the wife when pulling into the driveway or maybe if you drive into a bit bigger garage and want to avoid emissions while in there. But mostly the button should be ignored and trust the car knows what's best.

There is also a non-hybrid version of the Yaris Cross (and Yaris mk4 too i believe), so with some digging you might be able to find their usual MPGs. 

[Cyker]

To be fair, half the reviewers still think there is an actual belt-and-cones CVT system in the car, so you can't expect much from them  

 

[CruxisCore]

3 minutes ago, Cyker said:

To be fair, half the reviewers still think there is an actual belt-and-cones CVT system in the car, so you can't expect much from them  

 

Also B is for regenerative braking 😬

EDIT: For the new people who might miss the point: it isn't.

[Dala]

the information about the possibility of charging with a longer ride will not be true

without external charging, it is not possible to keep the car Battery in the best condition

 

[Graham47]

53 minutes ago, Dala said:

@Dala

 

53 minutes ago, Dala said:

the information about the possibility of charging with a longer ride will not be true

It would be helpful if you also provided an explanation of what you are demonstrating and how you arrived at this conclusion !

without external charging, it is not possible to keep the car Battery in the best condition

[Dala]

7 hours ago, Graham47 said:

@Dala

 

the information about the possibility of charging with a longer ride will not be true

It would be helpful if you also provided an explanation of what you are demonstrating and how you arrived at this conclusion !

without external charging, it is not possible to keep the car battery in the best condition

12.3V is not a fully charged car Battery
according to the graph, 99% of the time (40 minutes, 60 minutes) of driving, the system maintains the car Battery at a voltage of 12.8V
12.8V is not a charging or floating voltage
this is not smart charging
this is a car Battery destruction system

this is probably why the current car battery does not last as long as the car battery in older cars

[Max_Headroom]

9 hours ago, Dala said:

without external charging, it is not possible to keep the car battery in the best condition

Does that include using ready mode as discussed in the thread? 

[Dala]

2 minutes ago, Max_Headroom said:

Does that include using ready mode as discussed in the thread? 

good question
I will post the "READY mode" voltage graph as soon as possible

[CruxisCore]

12,3v is still around 70% state of charge and does not by itself put the Battery in any kind of danger or damage. Of course, it is less leeway before the Battery is in dangerous levels for it's own durability. But it's true that the car will never be able to charge the Battery to full with the parameters they charge with now.

Also, I suppose AGM temperature compensation may not 100% apply to a regular wet sealed battery, since most here dont seem to have AGMs in their different kinda of Yaris'

[CruxisCore]

My 12v USB charger + voltage meter thingie just arrived today. I figured no point testing it in my Aygo X but ended up doing it anyways. It's kinda interesting how much it lives under load. When I turned power on from the ignition but not the engine, it started at 12,4V (but obviously already under load) and rather rapidly dropped even below 12V before I fired up the engine. With the engine running (this is a regular non-hybrid, so probably the usual alternator driven by the ICEs belt or so) it was at 13,8v. When I turned off the car just handful of seconds later again, it dropped to 12,7V. Keeping power on after turning engine off it rather rapidly kept dropping again until I just turned power off again.

Not actually sure if I can properly see the screen in the Yaris Cross cos the 12v socket isnt very visible to the driver, but it's not like I plan on staring at it all the time 😄 

I also wanted USB charging ports that wouldnt be connected to the infotainment as I dont want my lady's phone to try connecting to Android Auto if she is just charging it while we drive or whatnot. So now I have 3 USB ports at the front 😄

 

 

[TopGeek]

16 hours ago, Graham47 said:

@Dala

without external charging, it is not possible to keep the car battery in the best condition

That seems to be true. I fully charged my 12-volt Battery last weekend, went out locally several times and did one trip of 100km during the week. Yesterday, I was using ACC mode for about 5 minutes and a warning came up saying "Battery low. Switch off Power" or words to that effect. That doesn't seem reasonable to me.

I put it on charge overnight and it was fully charged by this morning ......but, for how long?

[Graham47]

2 minutes ago, TopGeek said:

Yesterday, I was using ACC mode for about 5 minutes and a warning came up saying "Battery low. Switch off Power" or words to that effect. That doesn't seem reasonable to me.

Of course it could be that the warning message is triggered, whatever the true SOC of the Battery, urging you to either switch off on turn on ready mode so that you don’t deplete the Battery further.  You don’t know what the SOC was when you got the message, you only assume it was very low.  After all, you had only just fully charged your Battery.

[TopGeek]

2 minutes ago, Graham47 said:

Of course it could be that the warning message is triggered, whatever the true SOC of the battery, urging you to either switch off on turn on ready mode so that you don’t deplete the battery further.  You don’t know what the SOC was when you got the message, you only assume it was very low.  After all, you had only just fully charged your battery.

Too many unknowns. I shall have to get one of those cigarette lighter monitors, although I doubt they are very accurate.

[Roy124]

29 minutes ago, TopGeek said:

Too many unknowns. I shall have to get one of those cigarette lighter monitors, although I doubt they are very accurate.

Why?

I have a BM6 and its readout is different my voltmeter by a couple of points.  In fact I have 3 voltmeter as sometimes the voltage will jump all over the place. 

There is no reason to suspect that the plug in sensor would be inaccurate.   However while it might be inaccurate by a point or two you will be looking for difference rather than absolute.

[Dala]

Today driving 10 minutes - the car Battery was maintained at 12.8V by the system
then I left the car in "READY MODE" for 1 hour - the car Battery was charged by the system to 14.08V the whole time

I have to correct my previous post :

the information about the possibility of charging with a longer ride will not be true

without external charging.....or running in READY MODE...... it is not possible to keep the car Battery in the best condition

[CruxisCore]

2 hours ago, Roy124 said:

Why?

I have a BM6 and its readout is different my voltmeter by a couple of points.  In fact I have 3 voltmeter as sometimes the voltage will jump all over the place. 

There is no reason to suspect that the plug in sensor would be inaccurate.   However while it might be inaccurate by a point or two you will be looking for difference rather than absolute.

This. 

It's kinda what I often tell people about smart watches, that it's not that important whether it factually records that 10k steps accurately. But usually the device is still consistent with itself. Yeah, maybe when it says you did 10k steps its only really 8k steps, but that day when it tells you you have only 8k steps, you know that it's still less than what you usually walk kinda thing.

Same thing, a cheap 12v socket voltage meter might be off by a point or two compared to a professional multimeter, but so what? If you know that it is, that means that instead of freaking out at 12,1v you can freak out when it says 11,9v 😄

[Cyker]

4 hours ago, Roy124 said:

Why?

I have a BM6 and its readout is different my voltmeter by a couple of points.  In fact I have 3 voltmeter as sometimes the voltage will jump all over the place. 

There is no reason to suspect that the plug in sensor would be inaccurate.   However while it might be inaccurate by a point or two you will be looking for difference rather than absolute.

I can imagine cheap ones being quite bad - They have terrible contacts and connections which create a lot of extra resistance, throwing the readings off.

I had a particularly bad one you had to twist around in the socket a few times to try and get a good contact or it read something stupid like 7v  

That's why I like to buy stuff people recommend here - It turns out my usual tactic of buying the cheapest one doesn't always give the best results. Never fathomed why!   

[Roy124]

Cyker. I loved a destructive comparison between two 'identical' Apple charger plugs.

Simply both used identical Chinese plastic mouldings of the destroy to open design.  Both output the required voltage.  The internals were similar though the knock off had fewer components.

Bottom line, they were probably both knockoffs. 

[Cyker]

Ah, you might like bigclive's channel on Youtube, he likes dismantling things like that.

He has a variety of useful equipment, like his custom X-ray machine (A hammer), and an explosion-containment device (Pie dish)

 

[CPN]

I would have thought that the car's own systems would be the most accurate measurement of all coming via the OBDII port...

...bear in mind that this is with the car "at rest" in the garage switched off and fully locked up. Also, my Battery is currently 3 years old since the car was built.

(also bear in mind that a fully charged conventional (sealed or otherwise) 12v car Battery made up of 6 cells should be 6 x 2.2v = 13.2v when fully charged at 100% health - i.e. just about new)

... and finally, that displayed voltage matched my calibrated Fluke 77 multimeter reading across the Battery. 

Edited July 25, 2023 by CPN
The last bit...

[Dala]

I use this Light Car Adapter , I like this method of measurement, measurement via this adapter is quite accurate.

https://youtu.be/FeN8ULJnIas

 

 

I use BM6 for more accurate calculations : https://www.aliexpress.com/item/1005004458755180.html

According to my all available data - driving the car over day -battery cannot be guaranteed charged. Only external charging (wired, solar ...) or "READY" mode. Driving in night is charging car Battery OK - headlights are is ON (voltage 14,2-14,4V)

[Roy124]

9 hours ago, CPN said:

would have thought that the car's own systems would be the most accurate measurement of all coming via the OBDII port...

It will be an accurate source, the limitation is with the display system specification and its circuitry.

[TopGeek]

Cigarette lighter voltage indicators do not and cannot give a true measurement of the voltage at the Battery terminals. The only type of device that can do that is a laboratory calibrated voltmeter connected directly to the Battery terminals. Consequently, references to the SoC levels are meaningless, except when measured under controlled conditons. Anything else is subject to variable factors such as the votage drop between the Battery and the cigarette lighter, current drawn by other systems along those several metres of cable, the accuracy and consistency of the measuring device.

Cheap  voltage indicators are inherently inaccurate, non-linear and subject to temperature variations. At best, they can only give an approximation of the true battery voltage.

Those devices only give a relative indication of the SoC of the 12-volt battery. The voltage indicated cannot be regarded as true battery voltage.

So yes, they are useful but only in relative terms.