12v battery maintenance, issues, etc.

[CruxisCore]

Well, a Battery doesn't get better from a Yuasa. Good to know there is a Yuasa at 45 Ah that fits if it goes to that for myself too. C-HR and Corollas use 45 Ah, but the Yaris has been stuck with 35.

[RonYarisX]

Scrub my post - I was talking crap as usual 🤣

 

Edited August 4, 2023 by RonYarisX
information was incorrect.

[Xerapin]

I've been keeping an eye on the voltage readout from the cigarette lighter port since I got it, I also had a Dashcam fitted (front and rear) on Tuesday, I haven't driven anywhere in the car since Monday.

Everytime I turn the car on (engine, not accessory) it starts at 12.2, drops to 11.9 then goes to 14.0, i leave the car for 10 minutes in 'Ready' mode, and it goes upto 14.2, I've not seen it do _anything_ different and I've checked it every morning  for the last 3 days.

Okay, so I know the cigarette lighter voltage meter probably isn't the most scientific of readings, but the fact its consistent gives me hope the cars not draining, esp. now with the Dashcam installed in parking mode. (On a drive, so its not going off all the time mind you).

In my paranoia I got the jumper cables Battery pack too, so at least I have them as backup 😄

[Derek.w]

22 hours ago, MaDProFF said:

I am talking about the 12 volt on the tesla, the 12 volt battery to be replaced with a 48 volt system in the future

It appears Tesla are using 12 volts Battery and some new production are supplied with a upgraded  16 volt batterys systems who knows what voltage upgrade will be next but it stop at 48 volts for controll circuits as above this voltage things become very dangerous and its no longer falls into the same safty category.

[CPN]

1 hour ago, Derek.w said:

It appears Tesla are using 12 volts battery and some new production are supplied with a upgraded  16 volt batterys systems who knows what voltage upgrade will be next but it stop at 48 volts for controll circuits as above this voltage things become very dangerous and its no longer falls into the same safety category.

Indeed and that reminds me of something that was always drilled into us during the days of my Services Technical training and University days, "it's not the voltage that will kill you but the current will". Any voltage above 30 milliAmperes is the starting danger level for human beings... DC is especially dangerous above that level... (and of course, in the case of our HEVs and BEVs, there is several Amperes floating about in the system...)

[CruxisCore]

Indeed. Tasers can momentarily do like 50k volts, just that the amperage is nonexistant

[CPN]

Bit off-topic but I remember commissioning a UPS system at a radar site in Oman back in the 80's. It was very intimidating in that it was bank after bank of series/parallel lead acid batteries constructed on bank after bank of steel racking. It was 240v final output but here's the kicker, it was rated at 1,500 AmpereHours!! During commissioning, we were having to use special probes etc to make sure that any AC ripple was as low as possible (from the charge station) and within safe limits. We had the probes set up onto the main output busbars and just as we had produced a good trace on the recording equipment to satisfy the requirements, one of the probes broke down almost in front of me and my assistant and threw us both back against the wall! The flash was so horrendous that we were both temporarily blinded for about 20 minutes!!! One major lesson learned, always respect high current installations! That UPS could keep the whole station running for 7 minutes whilst the no-break system generators kicked in and came online...

[Derek.w]

47 minutes ago, CPN said:

Indeed and that reminds me of something that was always drilled into us during the days of my Services Technical training and University days, "it's not the voltage that will kill you but the current will". Any voltage above 30 milliAmperes is the starting danger level for human beings... DC is especially dangerous above that level... (and of course, in the case of our HEVs and BEVs, there is several Amperes floating about in the system...)

My training days any voltage at 50 volts or above if the conditions are right can kill you.

With ac you stand a chance you be thrown off as the voltage reverse but that wont happen with DC.

[CPN]

1 minute ago, Derek.w said:

My training days any voltage at 50 volts or above if the conditions are right can kill you.

Absolutely.

1 minute ago, Derek.w said:

With ac you stand a chance you be thrown off as the voltage reverse but that wont happen with DC.

Exactly so... It's just a good job that neither of us was touching anything at the time (we had loads of safety gear on...)

[Tonycu]

Hi everyone

we have a 72 plate Yaris icon and we are going on holiday for a month in September so the car will not be used and parked up on the drive

I would like to know is it the hybrid Battery under the seat that needs a trickle charge or the Battery under the bonnet or both batteries need a trickle charge while we are away 

would a solar charger do the job and which Battery would I connect to,I could plug an electric charger into a  an electric-socket in the garage and run a lead to the car for the duration

any help and suggestions would be helpful plus what chargers I would need to buy

regards Tony  

[Roy124]

On 8/3/2023 at 10:43 AM, MaDProFF said:

 

Tony, it is the 12v Battery that needs looking after.  A solar charger might do the job provided it has a clear view of the sun when it's shining.  I believe you can plug into the OBC port below the steering wheel.

You could also us a 12v smart charger which can be connected direct to the Battery (is it under a rear seat) or to the positive blade connector in the fuse box of that is what you have.

If you doubt the ability of solar, a charger is the way to go provided you can ensure a safe, waterproof connection.

Don't worry about the HV Battery.

 

[Tonycu]

Thank you Roy for taking the time to help and advise me

What trickle charger do you advise /use

One of the problems I have is the wife is worried that her car is at danger of setting on fire if I leave a trickle charger on for the month we are away?

I can make sure no water gets at the charger and extension lead while attached to the car but she still worrys

Regards Tony 

[Tommy X]

5 hours ago, Tonycu said:

Thank you Roy for taking the time to help and advise me

What trickle charger do you advise /use

One of the problems I have is the wife is worried that her car is at danger of setting on fire if I leave a trickle charger on for the month we are away?

I can make sure no water gets at the charger and extension lead while attached to the car but she still worrys

Regards Tony 

Hello Tony, If you have concerns about leaving the car connected to a smart charger I would suggest just before you go away fully charge the Battery, preferably overnight, hopefully when you return it will be ok and you can give it a top up charge. C Tek chargers are very popular, I use this one Buy Ring 4A Smart Charger and Battery Maintainer | Car battery maintenance | Argos  

[Roy124]

Tony, I agree about the CTEK charger.

Two other suggestions:  ensure the charger is well ventilated and not on combustible materials.   The other is to get a time switch.  If you got a 7-day switch you could set it for a couple of hours once a week.

 

 

[Dala]

Or GSM plug

 

[anchorman]

Or you could just leave it.  Mine was on the CTEK for 3 weeks last time.  It just goes into maintenance mode and cycles the Battery to keep it healthy.  It’s why I tend to treat these cheap so called smart chargers with caution because they might not be so dependable in those conditions.  There’s baked beans and there’s baked beans.

[Tonycu]

Hi 

I have decided to go with the CTEX MXS 5 0 charger (got it off the Tanya Battery site £66.10 and £5.99 delivery next day) and use it on a weekly basis as my wife recently retired and the car is not used as much as it was on the daily commuter run , 

On our month long break I intend to to use a solar charger as advised on this forum as the car will be parked up on the drive in a  sunny spot ,but also give the Yaris an overnight charge with the CTEX the day before we leave ,hopefully this should keep the Battery in good condition

Once again thank you all for alI your advice and help ,what a brilliant site for Yaris owners

Regards Tony

[Roy124]

Tony, really money well spent and probably last many years.

I bought a Battery charger in 1965, British made, metal case with ventilation holes.  It could bang out 5 amps or 1-2 amps, not that I knew much more than V=IR in those days.  It failed after 40 years and I bought a swep up Ring one that  I had to replace when I got my Toyota. 

Cheap if it avoids waiting for the AA man.

[Derek.w]

Last Battery charger that I repaired replaced its metal air cooled rectifier with a modern Bridge diode rectifer.

[anchorman]

12 hours ago, Roy124 said:

Tony, really money well spent and probably last many years.

I bought a battery charger in 1965, British made, metal case with ventilation holes.  It could bang out 5 amps or 1-2 amps, not that I knew much more than V=IR in those days.  It failed after 40 years and I bought a swep up Ring one that  I had to replace when I got my Toyota. 

Cheap if it avoids waiting for the AA man.

I had one of those chargers.   I wonder where it is, I must look.  

[TonyHSD]

My dad has one of these relics with manual controls and gauges, looks like pro cassette player and I believe it’s made in Russia 🫢 Still work’s though and he uses it more often than the smart one I gifted to him. 😂👌 

[anchorman]

Hey, look what I’ve found.  I bought it from Bower’s, a major auto electric supplier in Stoke during by apprentice days so late 70s maybe.  It absolutely demolished a week’s wage.  That looks like teak vinyl - none of your cheap pine vinyl.

[RickyC]

I've a voltage indicator in the 12V plug and I'v noted a strange behavior.  

After a trip of 20/30 minutes, when I'm going to park my car in the garage, usually I read 14V.  As soon I move the gear lever to P, voltage drops to 13.4  and stays stable. 

I open garage door, I move the gear to D and voltage comes back to 14V.  I park the car, move to P and back to 13.4. 

I've tried, many times to move the gear fom P to D or R and back and everytime it happens.  

When I turn on the car for the first time,  voltage jumps immediately to 14V even with lever still in P.  

So I wonder if leaving car in P really charges the Battery. 

[TonyHSD]

1 hour ago, RickyC said:

I've a voltage indicator in the 12V plug and I'v noted a strange behavior.  

After a trip of 20/30 minutes, when I'm going to park my car in the garage, usually I read 14V.  As soon I move the gear lever to P, voltage drops to 13.4  and stays stable. 

I open garage door, I move the gear to D and voltage comes back to 14V.  I park the car, move to P and back to 13.4. 

I've tried, many times to move the gear fom P to D or R and back and everytime it happens.  

When I turn on the car for the first time,  voltage jumps immediately to 14V even with lever still in P.  

So I wonder if leaving car in P really charges the battery. 

Perhaps that’s all it needs and your Battery is in good health. 
 

[Dala]

Two consecutive days - same path - same time - same weather

 

From a voltage of 12.31V (70% SOC) and up - smart charging - the decision is: no need to charge

From a voltage of 12.21V (60% SOC) and below - smart charging - the decision is: need to charge

Other interesting findings - from 12.30 V (70% SOC) and below - very reduced parasitic consumption

by me the breakpoint is 12.3V

Quick calculation of parasitic consumption:
12.29V = 67.5% SOC
12.26V = 65% SOC
2.5% SOC difference
35 Ah x 2.5% = 0.875 Ah / day = 36 mA / hour

It's summer. In winter, these values will be worse.

I know that the table is for AGM, but WET will be approximately the same value.