12v battery maintenance

[DC_Ms]

11 minutes ago, TonyHSD said:

You can try but you may damage the cable. Perhaps just leave it like that or undo the nut and reposition the connector differently to allow the cable bending and cover closing if possible. This device connected directly to the battery I am not sure how will affect it. Have you measured with multimeter to see if any power drains happen while the car is off? 

No , at the moment I’m just ‘worried’ if the cover in that position would have any negative … I couldn’t connect the cable in other direction to offer the plastic cover to go down.

As for the Battery drainage , I’ll just have to live with it and see 🙂

[TonyHSD]

31 minutes ago, DC_Ms said:

No , at the moment I’m just ‘worried’ if the cover in that position would have any negative … I couldn’t connect the cable in other direction to offer the plastic cover to go down.

As for the battery drainage , I’ll just have to live with it and see 🙂

Don’t worry about the plastic cover then, it’s still on top so it’s safe. 👍

[camellia30]

12V Battery measurements during a ~20 minute drive.

The current was measured with a current clamp and a logging DMM.

The Battery voltage was measured at the OBD port with Car Scanner, as I only have one DMM.

You can see the car was charging the Battery for the first ~12 minutes and then again just before 13:00:00.

I can't explain the jump in battery voltage while the car was locked and asleep at 13:05, 13:15, 13:22.

I also failed to put the data on the same graph as the 2 devices sampled at completely different rates.

[AisinW]

@camellia30, I am afraid your reading is within noise/stability in your device capability.   The current reading after 13.10 looks more reliable.  Voltage reading is pretty noisy even if you put it between your fingers.  Voltmeter is way more sensitive than Ampmeter and much easier to built.  Your car is not completely sleep before 13.10 . 

@DC_Ms I also have Telematic device to get up to 30% dicount of car insurance.  Fortunately, it is stick-on device without any wiring  to the car.   In 7 months, I managed to get 22-23% discount without changing my driving habit, just drive naturally without thinking about it. I will refuse any Telematic or devices that connected to my car continously.  It can cause a huge headache.  We have such a High ECU BURNED rate from Telematic device that plug-in in our OBD-2 ports few years ago in the USA.  There are some Law suits filled to Insurance company who cause these issues.  I doubt you can win such battle in UK/Europe costumer protection systems.  

The telematic is a good thing at first but now my wife knows wherever I go. But we can just turn the bluetooth off if we do not want to be tracked by our partner/wife. LOL.

 

[naimen]

Im going on vacation soon and is going to leave my hybrid car for 5 weeks, should I disconnect the 12v Battery?

[AisinW]

On 7/5/2023 at 3:43 PM, naimen said:

Im going on vacation soon and is going to leave my hybrid car for 5 weeks, should I disconnect the 12v battery?

If you have 2.0L , You can also do easier steps. Open the fusebox in the engine bay and find the D/C CUT fuse. Remove it and all sensors and standbye remote will be completely off. You can use the key inside the FOB when you come back to open the door. For 1.8L, removing negative terminal is easy. Just make sure remove it at 1 quick unplug, do not do it in 10s or very slowly or you may get C1241 code. 

[Dala]

https://toyota-club.net/files/techdata/fuse/yaris_130.htm

[Mr Billiards]

Hi just ordered a new 2ltr Corolla GR Sport. My first hybrid car.

Upon reading the posts in this section of the forum I'm fairly concerned about the Battery maintenance issue.

I do not cover many miles a week + lots of short runs, so wondering what I need to do. Is it just a case of putting the car in 'ready mode' once a week for 60 minutes to keep the Battery charged.

I assume its the Battery in the boot of the 2ltr car that needs to be kept healthy. I have a ctek MXS 5.0 charger. Assume I could use it to maintain charge of the battery in the boot. Would I need to disconnect any battery leads before using the charger or can I just clip the charger leads straight onto the battery. 

All advice would be much appreciated.

 

 

 

 

[Dala]

When using ctek MXS 5.0, it is not necessary to disconnect the car Battery

[Roker]

There's  not much point in having a solar charger if you have to leave it in an airport multi story car park

[TonyHSD]

On 7/24/2023 at 5:52 PM, Mr Billiards said:

Hi just ordered a new 2ltr Corolla GR Sport. My first hybrid car.

Upon reading the posts in this section of the forum I'm fairly concerned about the battery maintenance issue.

I do not cover many miles a week + lots of short runs, so wondering what I need to do. Is it just a case of putting the car in 'ready mode' once a week for 60 minutes to keep the battery charged.

I assume its the battery in the boot of the 2ltr car that needs to be kept healthy. I have a ctek MXS 5.0 charger. Assume I could use it to maintain charge of the battery in the boot. Would I need to disconnect any battery leads before using the charger or can I just clip the charger leads straight onto the battery. 

All advice would be much appreciated.

 

 

 

 

Hi ,

No need to disconnect the leads. 60 min a bit on the longer side. 
What you can do instead is to keep the car as long as possible in ready mode once started, similar to back in the days when drivers once started their Diesel engines they had  left them running idle instead of stop start all the time. For example you take your family member to the local supermarket but you don’t want to get in and walk around,  you an stay in the car in ready mode and relax while they do the shopping. Usually 30-40 min are perfectly fine for the 🔋 to get a good charge. Another example if you wash the car yourself, just set in ready mode and then clean it up.
All that is necessary if you don’t drive often or your drives are shorter than 30 min each. And of course once in a while especially during cold winters you can connect a smart charger and let it fully charge your Battery slowly, this will keep the 12v Battery in healthy condition. 

[Mr Billiards]

4 hours ago, TonyHSD said:

Hi ,

No need to disconnect the leads. 60 min a bit on the longer side. 
What you can do instead is to keep the car as long as possible in ready mode once started, similar to back in the days when drivers once started their Diesel engines they had  left them running idle instead of stop start all the time. For example you take your family member to the local supermarket but you don’t want to get in and walk around,  you an stay in the car in ready mode and relax while they do the shopping. Usually 30-40 min are perfectly fine for the 🔋 to get a good charge. Another example if you wash the car yourself, just set in ready mode and then clean it up.
All that is necessary if you don’t drive often or your drives are shorter than 30 min each. And of course once in a while especially during cold winters you can connect a smart charger and let it fully charge your battery slowly, this will keep the 12v battery in healthy condition. 

Thanks for the info, much appreciated.

It seems leaving the car in ready mode for 30 to 40 mins when washing the car once a week would be sufficient to keep the 12v Battery charged.

I assume there is no need to disconnect any 12v Battery leads when using a Smart Charger, just clip the Crocodile clips from the Smart Charger directly onto the + & - Battery terminals. 

Just clarifying, because I had a 2019 Honda Civic and the routine was to connect the Smart Charger + directly to the battery terminal and connect the - to a bolt / fixing on the bodywork under the bonnet adjacent to where the 12v battery was located.

 

 

[TonyHSD]

1 hour ago, Mr Billiards said:

Thanks for the info, much appreciated.

It seems leaving the car in ready mode for 30 to 40 mins when washing the car once a week would be sufficient to keep the 12v battery charged.

I assume there is no need to disconnect any 12v battery leads when using a Smart Charger, just clip the Crocodile clips from the Smart Charger directly onto the + & - battery terminals. 

Just clarifying, because I had a 2019 Honda Civic and the routine was to connect the Smart Charger + directly to the battery terminal and connect the - to a bolt / fixing on the bodywork under the bonnet adjacent to where the 12v battery was located.

 

 

That’s right 👍

[Roker]

On 7/16/2022 at 9:27 PM, Geoffrey Bailey said:

Toyota guidance as follows:

Toyota hybrids generally contain two batteries: a 12-volt battery (which powers systems such as the headlamps and audio) and a high-voltage hybrid system battery (which supplies the power to start the combustion engine and drive the electric motors).

The simplest way to maintain charge in both of these batteries is to simply go through the normal start procedure: press the ‘Start’ button with your foot on the brake and ensure the ‘Ready’ light is illuminated on the dashboard.

We recommend you put the car in ‘Ready’ mode for about 60 minutes before switching it off again and repeat the process at least once a week.

With regards to the information above, I'm interested to know what is the charging rate from the hybrid system battery to the auxiliary battery whilst in ‘Ready’ mode.

(Toyota Corolla Hybrid 1.8 owner)

That's interesting, I just measured the Battery voltage after standing overnight at 12.0v then started (engine not running) and the voltage was 14.2v, which proves it is charging from the hybrid Battery, so in theory if left for 1/2 hr or so there should be enough charge to start . Or will this not work because it cannot go into start mode, all toyota have to do is give us a method or switch to charge the flat Battery from the hybrid battery

[Don Mac]

2 hours ago, Roker said:

That's interesting, I just measured the battery voltage after standing overnight at 12.0v then started (engine not running) and the voltage was 14.2v, which proves it is charging from the hybrid battery, so in theory if left for 1/2 hr or so there should be enough charge to start . Or will this not work because it cannot go into start mode, all toyota have to do is give us a method or switch to charge the flat battery from the hybrid battery

The problem is that the 12V Battery has to start the car's electronics, which then close the relays to 'power up' the hybrid Battery.

If the 12V Battery doesn't have the power to do this, you get nothing.

[Roker]

6 hours ago, Don Mac said:

The problem is that the 12V battery has to start the car's electronics, which then close the relays to 'power up' the hybrid battery.

If the 12V battery doesn't have the power to do this, you get nothing.

But the 12v should charge from hybrid for 1/2 hr then the system will start

[Don Mac]

16 minutes ago, Roker said:

But the 12v should charge from hybrid for 1/2 hr then the system will start

That is what you would like to happen, but it won't.

I think that this is down to safety considerations, the hybrid Battery packs a lot of power and can cause a large fire/explosion if it goes wrong. Hence it is only connected by the car's electronics after the computer has run a series of checks to confirm that it is safe to do so.

[Derek.w]

I see to remember if you hold it in second key position for a few minutes it may give the 12 volt Battery a boost but it depends a lot on how flat it is.

Thats with other systems off like A/C

At the end of the day if you flatten the HV Battery then thats even a bigger lot more expensive problem.

It makes more sense just to give the 12 volt Battery a charge every 3 or 4 weeks just to keep it healthy.

[Roker]

On 12/22/2021 at 4:53 PM, Trewithy said:

I use a CTEK to maintain my battery but I don't disconnect the battery.  I just connect the red cable to the + terminal on the battery and the black cable to a lug on the cylinder head.  Do not put it directly on the battery - terminal.  

Why can we not connect direct to the Battery the negative is the same potential as the lug

[Mr Billiards]

I also own a CTEK, what can the negative charger lead be connected to when the Battery is in the boot?

[TonyHSD]

2 hours ago, Mr Billiards said:

I also own a CTEK, what can the negative charger lead be connected to when the battery is in the boot?

Negative terminal of the 12v Battery. Like this. 
 

Or if you jump start from under the hood connect to nearest bare metal bolt or nut, usually it’s the shock absorbers 3 nuts.  

 

[Tommy X]

2 hours ago, Mr Billiards said:

I also own a CTEK, what can the negative charger lead be connected to when the battery is in the boot?

Connect to the earthing point for the negative lead from the Battery if it's accessible   

[Mr Billiards]

On 8/30/2023 at 11:43 AM, TonyHSD said:

Negative terminal of the 12v battery. Like this. 
 

Or if you jump start from under the hood connect to nearest bare metal bolt or nut, usually it’s the shock absorbers 3 nuts.  

 

Thanks for the info

[Mr Billiards]

On 8/30/2023 at 11:48 AM, Tommy X said:

Connect to the earthing point for the negative lead from the battery if it's accessible   

Thanks for the info

[TonyHSD]

14 minutes ago, Mr Billiards said:

Thanks for the info

You are welcome