12v battery

[Dave47]

Does anyone know the type of 12v Battery fitted to the corolla hybrid 2.0. Is there anything different about it compared to a standard car Battery? The reason I ask is that it will only charge up to about 12.4v and according to what I can find online a 12v car Battery should charge to 12.6v or above.

[Gray86]

9 hours ago, Dave47 said:

Does anyone know the type of 12v battery fitted to the corolla hybrid 2.0. Is there anything different about it compared to a standard car battery? The reason I ask is that it will only charge up to about 12.4v and according to what I can find online a 12v car battery should charge to 12.6v or above.

Apart from being small, and an AGM I don’t think it differs much / at all from a typical car Battery. Be interested to hear of other views on this 

[APS]

11 hours ago, Dave47 said:

The reason I ask is that it will only charge up to about 12.4v and according to what I can find online a 12v car battery should charge to 12.6v or above.

As Graeme mentioned it should be an AGM lead acid Battery. Pretty standard. I'm sure someone can give you the exact spec.

That voltage doesn't sound catastrophic to me. Do you take the Battery out / disconnect it, before measuring? The car will always draw some current and reduce the voltage reading slightly. Cold temperatures will also make the Battery slow to recover and lower voltages will 'linger'.  

From experience, I've never had to replace a 12 V battery in our Toyota/Lexus hybrids (oldest one is 11 years).

[Dave47]

I charged the Battery as toyota recommends using 'ready on'. After over an hour it read 12.4v. I then used a digital smart charger but found that after 24hrs that it was still running and showing 75 percent charge, again 12.4v. This was done with the Battery in the car. 

According to Battery manufacturers' websites, a fully charged 12v car battery should read at least 12.6v or more. At 12.4v when fully charged indicates a faulty cell and if left at low voltage for a length of time can cause it permanent damage.

Thinking that the battery was at fault I arranged for a battery check at my local Toyota dealership and was informed (after an overnight charge) that there was no fault with the car or the battery. I’m not implying that the dealership results are incorrect, but according to the dealerships test result sheet, after an overnight charge the voltage was 12.23v and 233 amps. I’m confused by the conflicting opinions on how a fully charged battery at 12.2v is deemed healthy when battery manufacturers say otherwise? I did ask the question when I went to pick the car up, but was told ‘that’s how it is and the charger results said it was ok at that amperage’.

[AndrueC]

Are you having Battery related problems with the car?

[Dave47]

42 minutes ago, AndrueC said:

Are you having battery related problems with the car?

No, not having problems, just curious as to why this particular Battery has different values to what seems to be the norm.

[APS]

4 hours ago, Dave47 said:

According to battery manufacturers' websites, a fully charged 12v car battery should read at least 12.6v or more. At 12.4v when fully charged indicates a faulty cell and if left at low voltage for a length of time can cause it permanent damage.

I think you are right. I've just gone through my stack of batteries both in (but disconnected) and out of cars and measured. The results appear to backup what other internet sources say:

• Used but OK spare batteries that were charged a month or two ago: 12.5 - 12.6 V
• Healthy spare Battery, charged two months ago: 12.9 V
• Recently charged battery: 13.2 V

Might be a good idea to replace the Battery you have. Again, try taking it out of the car, charge it and see how how quickly the voltage drops (hours/days). 

Edit: Do check the thread about 12V Battery Maintenance as well. The Voltage you mention appears to be quite normal when the Battery is in the car.

[Dave47]

2 hours ago, APS said:

I think you are right. I've just gone through my stack of batteries both in (but disconnected) and out of cars and measured. The results appear to backup what other internet sources say:

• Used but OK spare batteries that were charged a month or two ago: 12.5 - 12.6 V
• Healthy spare battery, charged two months ago: 12.9 V
• Recently charged battery: 13.2 V

Might be a good idea to replace the battery you have. Again, try taking it out of the car, charge it and see how how quickly the voltage drops (hours/days). 

Edit: Do check the thread about 12V Battery Maintenance as well. The Voltage you mention appears to be quite normal when the battery is in the car.

Thanks for your reply. I would like to do as you suggest but reluctant to take the Battery out, fearing that it may cause problems to  the equipment that it supports. I recall that when I had some bodywork repair done, the garage disconnected the 12v Battery and ended up with a warning light that they had a problem putting right. They ended up having to contact toyota for a resolution.

[camellia30]

My manual says diconnect the Battery ground cable when using a Battery charger. It then goes on to list the issues you might have when reconnecting the ground cable.

If you are charging the Battery still connected to the vehicle harness then you are never going to see the open load voltage of the battery.

 

[Dave47]

3 hours ago, camellia30 said:

My manual says diconnect the battery ground cable when using a battery charger. It then goes on to list the issues you might have when reconnecting the ground cable.

If you are charging the battery still connected to the vehicle harness then you are never going to see the open load voltage of the battery.

 

OK and thanks. Will have a look at that