12v Battery problem

[Big_D]

I quite agree with you Tony. They would not be able to recharge a totally drained Battery. I have tested it on my motorbike Battery and is has maintained it, even on a cloudy day. The idea is for me to use it when we go away on holiday and are unable to start the car on a regular basis, so the Battery is maintained.

[SazJB]

I drive a CHR (2021 model - HYBRID). Last Saturday for the first time it would not start and lights flickering and control panel lights flashing etc. with warning messages. I called RAC and they replaced the Battery. I went to drive it yesterday and was shocked to see how much charge had been lost, problem with control panel lights again but not the headlights. I took it for a short drive and the Battery is now about 75% full. I will be unable to take it for long drives or frequently as I am very ill at the moment. I live alone as my sons are away at uni and don't feel confident enough to buy any type of charger etc. Can anyone give me any advice? It sounds like this is a known problem at Toyota? But not everyone is going to be able to use their cars more?

[UncleZen]

I leave mine in ready mode for 30+ mins to charge the Battery. ICE may or may not start during this process, if it does, it'll engane the gen and charge the hybrid Battery, which in turn charges the 12v Battery.

 

I should add that I can safely do this on my driveway 

[forkingabout]

I'm only doing short journeys ( 10 miles max a couple of times a day ) but the Battery normally drops to around 12.2 volts over night. 

Currently showing 12.4 volts after a couple of hours since parked. 

 

[Graham47]

It’s “time” not “distance “ that’s important….

20 miles per day should be more than sufficient to keep your Battery up.  12.4v seems to be the level Toyota design into the system.

[UncleZen]

@forkingabout how did you get that Battery voltage info?

[forkingabout]

2 hours ago, UncleZen said:

@forkingabout how did you get that battery voltage info?

Part of the extra security system fitted to the vehicle.

[Toyotalan]

Hi,

A week ago I knew nothing of the potential problem with hybrid 12V batteries. I've had a 2018 Auris for almost four years and did not experience any flat Battery difficulty.

However, last Sunday, with my recently acquired 2022 C-HR loaded up for a few days away, the car refused to start (Hybrid not connected message, then many other error messages). It took me a good few minutes to realise what the problem was; the Battery voltage was 6.5V.

I called my breakdown cover. The mechanic tried to get me started with a power bank without success; and then used jump leads, again without success. The thought of getting the vehicle to my dealer, 120 miles away, was a bit worrying. Anyway, we took the Auris and I spent a good few hours online, particularly on this forum.

I ordered a new charger (CTEK) and when I got home yesterday removed the Battery and left it on charge overnight. This morning I re-installed the battery and heaved a sigh of relief when the car fired up 😀.

My main reason for posting is to express my thanks to the contributors on the forum, especially FrostyBalls. I now know a great deal more about hybrids.

[wildtapholer]

I went to Toyota about this and the cars parked and stood outside are started once a week, they told me once started turn aircon to high and the car thinks it's being driven and keeps the car running until you have charged it enough.

[Cyker]

Supposedly just turning the headlights on is also enough to put the car into 'full 12v power' mode. Normally it doesn't always charge the 12v to increase efficiency but AC and headlights are 2 things that put the DC-DC converter into always-on mode. 

[Mark_P]

If doing any of those two things does recharge the Battery, wouldn't it makes sense to use the pre-warming feature either if you're on holiday or away for a few days?

This is assuming you can pre-warm the car if you're outside the UK that is.

Edited November 6 by Mark_P
Typos

[Toyotalan]

On 11/3/2024 at 4:44 PM, Toyotalan said:

I ordered a new charger (CTEK) and when I got home yesterday removed the battery and left it on charge overnight.

I also bought a jump starter pack which now resides in the boot of my C-HR. My question is this though: Why does my C-HR require a separate jump terminal when the 12V Battery is under the bonnet (and which should I use)?  I (think) I understand the need for the jump terminal in my Auris as the 12V Battery is hidden somewhere underneath my dog's backside; but the C-HR?

Toyotalan

 

[forkingabout]

The separate jump start terminal is mainly due to the small possibility of sparks when you connect a jump starter / leads can ignite the gases given of by the Battery causing it to explode.

Its vehicle manufacturers trying to protect the customer from injury, the vehicle from damage & also make things convenient.

[philip42h]

9 hours ago, Toyotalan said:

I also bought a jump starter pack which now resides in the boot of my C-HR. My question is this though: Why does my C-HR require a separate jump terminal when the 12V battery is under the bonnet (and which should I use)?

I guess that yours is a 1.8 - the auxiliary Battery on the 2.0 is in the boot. And I suspect that the fuse box is common between the two ... ?

And, have you considered how you access the contents of the boot when the Battery is flat, and the power door locks are inoperative? It might not be an issue in the C-HR, but with the RAV4 (and the bZ4X) I keep the jump start pack inside the car - 'cos I'd never be able to get it out of the boot!

[Toyotalan]

5 hours ago, philip42h said:

And, have you considered how you access the contents of the boot when the battery is flat, and the power door locks are inoperative? It might not be an issue in the C-HR, but with the RAV4 (and the bZ4X) I keep the jump start pack inside the car - 'cos I'd never be able to get it out of the boot!

Excellent point. Thank you 🙂.

We did manage to extract luggage from the C-HR via the back seat to allow us to take our trip in the Auris.