12v battery maintenance, issues, etc.

[Derek.w]

If your Battery voltage is above 12.85  its just fully charged if you have a reading of say 13.8 to 14.5 Battery is charging via dc to dc converter or altinator.

If you measure a static voltage with the same device at various points then voltage drop depending on length of wire its cross section area and any voltage drain ie load all play a part.

[Dala]

Yes, but the CAN BUS is supposed to show the correct voltage or not?

[isnsiie]

Before I check the Battery today, I let the car in ready mode for 40mins when I wash my car yesterday. Maybe next time check the voltage at pole first to see how much it can charge to the Battery. 

[Gerg]

9 hours ago, Dala said:

has anyone tried a CLAMP MULTIMETER to measure parasitic drain current?
the car battery would not have to be disconnected

Yes, I have had a Uni-T 210E multi meter for some years.  Measuring such small currents is not its strong point, but being mindful of the this, its readings are generally repeatable, and certainly worthwhile.

We have an Auris though.

[IT Troll]

17 hours ago, Roy124 said:

Just make sure you can get at it when the car is locked down.   Somewhere accessible near the driver's seat for instance. 

That's a damn good point. I've stupidly put mine under the boot floor. 🤦‍♂️

In my defence, this is the first car I've had which requires power to open the boot. 

[Roy124]

There was a very clear description of accessing the Corolla under floor boot area from inside.  😁

The better solution was calling for help. 

 

[Cyker]

This sort of thing is where the undertray storage or extra glovebox from the Mk1 and Mk2 Yaris would have been useful!!

[Graham47]

1 minute ago, Cyker said:

This sort of thing is where the undertray storage or extra glovebox from the Mk1 and Mk2 Yaris would have been useful!!

Doesn’t the Mk4 have additional storage in the armrest ?

[Cyker]

Yeah but I don't think it's enough to hold a jump starter; It's really very small - Maybe a small towel or a couple phones.

[Dala]

23 hours ago, Dala said:

has anyone tried a CLAMP MULTIMETER to measure parasitic drain current?
the car battery would not have to be disconnected

https://www.aliexpress.com/wholesale?trafficChannel=main&d=y&CatId=15370301&SearchText=CLAMP+MULTIMETER&ltype=wholesale&SortType=total_tranpro_desc&groupsort=1&page=1

according to measurements it could work

https://youtu.be/9azDW7NSCjo

[Derek.w]

Why not just fit a solar charger to replace the drain on the electronics.

Mk4 Yaris armrest storage is to small for a jump starter but you can push one under the drivers seat.

[Rhymes with Paris]

7 hours ago, Cyker said:

This sort of thing is where the undertray storage or extra glovebox from the Mk1 and Mk2 Yaris would have been useful!!

Did your mk1 have the under front passenger seat sliding tray?

When I found mine,it had a first aid kit in it.

[Graham47]

9 minutes ago, Derek.w said:

Why not just fit a solar charger to replace the drain on the electronics.

 

And what happens if @Newbie47 finds the solar charger hasn’t put enough back ? Remember, they’re looking at winter needs.

[Cyker]

18 minutes ago, Rhymes with Paris said:

Did your mk1 have the under front passenger seat sliding tray?

When I found mine,it had a first aid kit in it.

Yeah it did! Used to store the user manual and a road atlas in it  

I miss having one in the Mk4 - There were so many more places to put stuff in the Mk1 and Mk2!!

 

[Roy124]

My Merc had a lidded box under the frobt of the driver's seat marked with a first aid symbol.   Excellent. 

[Derek.w]

Winter needs thats why I have a 20 watt solar panel you need to brush the snow off but at least I receive some charge.

[dave hendy]

How easy is it to get access to the 12v Battery on the Mk4 Yaris as I might want to attach my solar charger directly to the Battery rather than using the obd2 socket?

[TruBlu]

leave the panel on the dashboard with the wire running between the door and door frame, then under the bonnet to the connection point in the fuse box (under RED tab). Connect the negative to the suspension bolt close by. My panel has a blue light that flashes when charging and produces more than 14V. Hope this helps.

[dave hendy]

1 hour ago, TruBlu said:

leave the panel on the dashboard with the wire running between the door and door frame, then under the bonnet to the connection point in the fuse box (under RED tab). Connect the negative to the suspension bolt close by. My panel has a blue light that flashes when charging and produces more than 14V. Hope this helps.

I was hoping to connect directly to the 12v Battery, possibly under the rear seat 🤔

[Cyker]

You can, it's just a bit of a faff - There is an access door at floor-level of the rear bench that lets you get at it, but it's quite cramped so you may have to take the rear seats out to get better access

[dave hendy]

52 minutes ago, Cyker said:

You can, it's just a bit of a faff - There is an access door at floor-level of the rear bench that lets you get at it, but it's quite cramped so you may have to take the rear seats out to get better access

I will have to have a look 👍

[TruBlu]

Why do you want to connect straight to the Battery?... it makes no difference. Anyway, none of us should be doing this or worrying if our cars will or will not start. The batteries in Toyota hybrids are to small and this issue needs to be rectified by the manufacturer. I've mentioned this to many people and they are now put off buying a hybrid. Also, it's quite embarrassing to have paid £22,000 plus for a brand new car that requires a jump starter in the boot or a solar panel on the dash. Give me my non-hybrid Auris back please with no Battery issues in 13 years.

[dave hendy]

6 hours ago, dave hendy said:

I will have to have a look 👍

After a bit of difficulty I managed to connect both the lead for the solar charger and the lead for my Battery tender for when I put the car in the garage. Hopefully this will prevent me from having any Battery problems in the future. Yes it’s a bit of a pain and I haven’t had to do it on a car before but I have had Battery problems with BMW motorcycles going flat for over 15 years.

[Derek.w]

No need to remove the rear bench seat just remove the plastic trim below the seat on drivers side.

Pullout plastic rivit heads then you can remove the body of the rivit then its a case of just easing the panel section up.

You can then remove the Battery clamp that holds Battery to floor this allows Battery to move forward slightly.

Remove ground wire first at terminal post then make shure it wont spring back to make contact.

 

[CPN]

17 hours ago, dave hendy said:

How easy is it to get access to the 12v battery on the Mk4 Yaris as I might want to attach my solar charger directly to the battery rather than using the obd2 socket?

Why are you worrying about using the OBDII socket? Its direct Battery feed contact is rated at 4A by design and specs requirement and I don't know of any solar panel trickle charger available on the market right now that can come anywhere close to providing 4A (under load) even in direct sunlight. This has already been discussed to death in another thread. I've been using my 20W solar charger now on my last 3 Yarises (2014 & 2017 Mk3s & my latest 2020 Mk4) without any ill effects at all and it does a good job in keeping the Battery in good health (I'm lucky that my car faces due south when it is parked up).