12v battery maintenance, issues, etc.

[jthspace]

17 minutes ago, HarryW2024 said:

Quick question, I’ve skimmed this thread but as it’s 113 pages long I’ve probably missed it! I have campervan with solar etc and keeping an eye on power (electrical) usage/management is second nature.

What type is the battery?

what size is the battery in aH?

do the latest 2024 cars have an improve auxiliary battery, (I have a YCP 130 coming mid sept) 

im presuming/hope having a 2 week holiday is going to lead to a flat battery….

TIA….

A slightly larger AH Battery is

YBX5202 YUASA YBX5202 YUASA 12V 45AH HSB202

I fitted to my Yaris as I'd read of issues and as I didn't know the history (number of times flat etc) I upgraded. It's a straight fit, identical size.  

I was hospitalised for 19 days and the car started up with no issues at all.

Cheapest supplier I could find

[Cyker]

The new cars have the same Battery, but they should be in proper working order.

(We, or at least me, suspects that a lot of the problems are due to the batteries being left unattended during Covid, and then subsequently being installed in cars after they'd already experienced some degradation) 

I suspect I have one of those batteries, but because I drive so much it's not had much chance to discharge. I've left the car for up to 10-12 days now and then during the holidays, and it's always started up first time, although I also keep a portable jumpstarter in the car juuuuust in case...    

Once I even left the sidelights on all day, but the car suffered no ill effects and still started (Much to my relief!), so it's by no means a certainty the problem will occur. If the car is used regularly I'm sure the Battery will be fine.

I would recommend a good shakedown run after purchasing the car (I went for a 2 hour hoon when I got mine just to get a feel for it - My first non-manual and first hybrid!  ) - There was one poster who bought the car then immediately went on holiday for a month and was complaining the car was dead when they came back... don't do that  

 

[HarryW2024]

I was hoping with the electrical updates that went into the new 130 they might have revisited the auxiliary side too, particularly as it has the smart connected live all the time and the electric tail gate. All of which is greater than the previous parasitic draw before you get in and switch it to ready mode.
Time will tell. 
 

do we know if the aux is just a old school (cheap) wet lead acid, AGM, Calcium or lead carbon or even better a lifePo type fitted? 

[Cyker]

It is the cheapest of the cheap! A 1980s flooded Battery, not even an EFB!

However it is at least sealed, so shouldn't leak acid everywhere, and is a lot cheaper to replace than e.g. the Mk3 Yaris hybrid's 12v Battery, which is the much more expensive AGM type!

 

[HarryW2024]

Ok, so anything under 12.06v is going to damage it and knock life out of it pretty quickly.

do we know what the quiescent parasitic draw is ( I.e. doors locked just sitting there).

[Cyker]

No idea! Someone was trying to measure that based on how much it lost over night but I don't know if they got a useful result.

You can skim the thread otherwise I'm sure someone with a better memory than me will post in the morning!

[HarryW2024]

You could measure parasitic draw quite easily with a multi meter between Battery earth and earth, but you have to put it in series. However that’s only going to measure that instance and not measure say the smart connect reporting in over a 24hr period, nor if you open the boot once if twice a day.

On campervans you fit a series shunt between the earth and Battery negative, mine is bluetooth enabled too (Victron smart shunt btw), what that does is measure the whole current in and current out giving you the net remaining. You can also see the peaks and troughs too as things like the fridge will cut in and out (cycle). Golden rule is never let a wet Battery go below 50% (approx 12.06v).

let’s see how I get on with my usage cycle of the YC, I will use at least 5 days a week but most will be under 5 miles interspersed with 10 mile motorway runs. I’m out in the camper say 6 times if the year up to 2 weeks at a time but most trips are a week or less.

i expect to do about 7k miles per year in the YC…..

[dash]

Voltage plot over a 5 day period of recent non-use of car. Not sure what the spikes are, dodgy BM6 voltage monitor or car 'checking-in' with Toyota?

[Chas G]

18 hours ago, jthspace said:

A slightly larger AH battery is

YBX5202 YUASA YBX5202 YUASA 12V 45AH HSB202

I fitted to my Yaris as I'd read of issues and as I didn't know the history (number of times flat etc) I upgraded. It's a straight fit, identical size.  

I was hospitalised for 19 days and the car started up with no issues at all.

Cheapest supplier I could find

£53.98 is an absolute bargain as long is the delivery cost is low.

[jthspace]

36 minutes ago, Chas G said:

£53.98 is an absolute bargain as long is the delivery cost is low.

£62-ish delivered.  I think I paid about £70 earlier in the year. 

[HarryW2024]

Just done a bit more trawling through the archives. Someone posted they measured the parasitic draw on a Auris, so not a million miles away, that was 0.05a, ergo 1.2a per day.

if you assume your standard 35aH Battery is 100% and you should never take more than 50% out of a lead acid Battery, lest you damage it. Then that gives you about 14.5 days.

If however assume your Battery is more likely to be at 80% charge then it drops to just over 11 days.

For the suggested 45aH replacement then those figures for 100/80% go up to 18/15 days respectfully.

All the above assumes you haven’t nipped out and put into ready mode twice a week 😂…

[Graham47]

35 minutes ago, HarryW2024 said:

All the above assumes you haven’t nipped out …..

And that the draw remains constant over the xx days.  Some have posted data suggesting it drops after a couple of days.

[jthspace]

1 hour ago, HarryW2024 said:

For the suggested 45aH replacement then those figures for 100/80% go up to 18/15 days respectfully

Which ties in with the 19 days my Yaris was left unattended and "started" completely normally on the Yuasa Battery.

[hind]

Also include the huge capacity loss after the first Battery discharge incident and we have a week max 😉

[Chas G]

Happened to see this which relates to Hyundai's approach to 12 volt Battery issues.

 

[HarryW2024]

Now that’s the sort of thing Toyota should be putting into its hybrid vehicles. The question is why not? 

[dash]

They should be allowing the HV Battery to charge the 12V Battery while the car is parked up. My previous EV did this. I know the Yaris HV Battery is much smaller than those in EVs, but if level of the HV battery got too low then charging of the 12V battery could be suspended.

[hind]

Isn't this a kind of security measure to prevent high voltage from accessing anything behind the contactor without the ignition? So the mechanic can work on the car without worrying that the system may wake up randomly and energize the DC/DC for example? I know that there is a service fuse in the HV Battery but yeah, better safe than sorry.

Another thing would be the effect of discharged HV vs discharged 12V Battery. The latter can be fixed by the simple booster. The former requires the visit in the specialized workshop which can feed the high voltage and current to the Battery in a safely and designed manner. 

[Paul john]

2 minutes ago, hind said:

Isn't this a kind of security measure to prevent high voltage from accessing anything behind the contactor without the ignition? So the mechanic can work on the car without worrying that the system may wake up randomly and energize the DC/DC for example? I know that there is a service fuse in the HV battery but yeah, better safe than sorry.

Another thing would be the effect of discharged HV vs discharged 12V battery. The latter can be fixed by the simple booster. The former requires the visit in the specialized workshop which can feed the high voltage and current to the battery in a safely and designed manner. 

Huh?

[CPN]

32 minutes ago, Paul john said:

Huh?

Why the "Huh?"? A quite accurate description of the two scenarios by Marek I would have thought...

[HarryW2024]

I read the Hyundai version is a manual activation of the HV charging Dc/DC circuits on a timed 15 seconds with a push of a button by the driver. It’s probably a simple sprung contactor.
 

That seems like a perfect half way house to the fully automated solution with complex voltage monitoring and automation, against the Stone Age you have to manually connect a booster to the 12v yourself.

[jthspace]

7 minutes ago, HarryW2024 said:

I read the Hyundai version is a manual activation of the HV charging Dc/DC circuits on a timed 15 seconds with a push of a button by the driver. It’s probably a simple sprung contactor.
 

That seems like a perfect half way house to the fully automated solution with complex voltage monitoring and automation, against the Stone Age you have to manually connect a booster to the 12v yourself.

Bit like leaving it in READY mode?

[HarryW2024]

No not quite, the system detects the 12v is being discharged too far and isolates it. On Toyotas it will just continue until it stops working. At that point you can no longer select ready mode as you have no 12v left. On the Hyundai version it switched off the 12v to protect the 12v from being killed dead. The 12v reset button does though in effect become a way of selecting ready mode as the system has preserved enough of the 1/v to allow you to get into ready mode.

 

well that’s how I read it and something Toyota should consider given the amount of grief dead 12v batteries seem to cause.

[jthspace]

18 minutes ago, HarryW2024 said:

well that’s how I read it and something Toyota should consider given the amount of grief dead 12v batteries seem to cause.

After the "parked up during & after Covid" period, I believe the occurrences of flat 12v batteries has fallen; it's also a better understanding that Hybrids are not the same as petrol and need a slightly different approach to ownership.

Notwithstanding that "sales" don't seem to point that out.

[HarryW2024]

Agree, however if you went on holiday for say 3 weeks which system would better guaranteed to start on your return……