At present, I'm only using e-mode as our journeys are within a 30-mile range. When on charge does the 12-volt battery charge as well as the main battery? I'm concerned about it getting low on charge and don't want to have to connect a trickle charger onto the 12-volt battery. Thanks in advance. Jim

 

The alternator will charge the 12v battery as it does on a non hybrid car. The main battery will charge when plugged in and a very small amount with regen under braking/coasting depending on how you have it set up. My inlaws have a new Rav4 hybrid and during lockdown did zero miles for about 5 months they then found the 12v battery was flat and needed a visit to Toyota to charge and reset everything. They now have a trickle charger from Toyota to plug it in when they are not going to be using it for a while (they have an Aygo for running about) I have a ctek trickle charger for my Mk3 VRS that I plug in if it is going to be idle for a few weeks. 

Thanks Liteboy. I used a CTEK trickle charger for our Karoq, plugged into the boot socket, but the iV is not suited and the earth point and positive need to be connected to the charger under the bonnet. Is the alternator running when the e-motor alone is used? I understand how the main battery charges, but my original query was whether the 12V battery charges at the same time as the main battery. My only way of checking is to measure the resting voltage.

2 minutes ago, Jim2015 said:

My only way of checking is to measure the resting voltage

 

That seems like the easiest way to confirm one way or the other. Seems like a crazy design for the 12V battery not to get at least trickle charged when the car is plugged in, but I suppose there may be a valid reason for not doing so.

 

Does the owners manual specifically prohibit connecting a charger via the boot socket? I would expect it to forbid connecting directly to the battery posts, but you wouldn't be doing so by charging via the boot socket, I suspect.

38 minutes ago, Wino said:

Seems like a crazy design for the 12V battery not to get at least trickle charged when the car is plugged in, but I suppose there may be a valid reason for not doing so.

The manual says this - "The 12-volt vehicle battery is automatically charged when the high-voltage battery is charged". Or am I being dense (which sometimes is highly likely)?

49 minutes ago, Jim2015 said:

a CTEK trickle charger ... the iV is not suited 

Why not? Can you explain, please?

 

Thanks to all those who replied. The dealer told me to connect a charger via the earth point and +ve battery terminal, but the fuse box cover must be removed (handbook info). The manual also states Sir Ron Norriss's observation, so I'll check the resting voltage later today. The IC engine has not run recently.

15 minutes ago, Jim2015 said:

The dealer told me to connect a charger via the earth point and +ve battery terminal

 

Seems like it's irrelevant anyway now, but if the boot socket is permanently powered I think it would be effectively the same connection. Unless the fuse box cover has some relevance (electrical interlock?) other than accessing the places mentioned, which seems unlikely.

Well, the flat 12v battery finally got me. 

Recently, with  fully charged high-voltage battery I did a 21-mile round trip. There were 11 miles of electric charge remaining when I got home. The car was put on charge until high-voltage battery, via the app, indicated fully charged. Then the car was garaged all of the following day.

 

The day after there was no response to either key. Skoda Assistance arrived and concluded the 12v battery was dead. This was a surprise as the high voltage battery was fully charged 36 hours earlier and I understood that charging this battery also charges the 12v battery.

 

The car then spent the next 3 weeks with the dealer as they tried to identify and remedy the fault. The car has now been returned to me in good working order but with no conclusive reason as to why the 12v battery of this new car went dead. There was a suggestion that my driving pattern (retired, making short trips with occasional 100+ miles journeys) caused the fault. I can't accept this because after each use I charge the high voltage battery and, to repeat once more, the manual says this - "The 12-volt vehicle battery is automatically charged when the high-voltage battery is charged". I can only conclude that the manual  statement is wrong. I can't believe that with a new car I need to use a battery charger. If someone can post a photo showing the +ve and -ve terminals of the 12v battery, I'd be grateful. There are no markings that I can see and the pix in the manual are rubbish.

 

Finally, I have used a CTEK battery conditioner on two cars since 2010. Impressive performance but, as I asked earlier, can someone tell why it is not suitable on these Octavia iVs?

What a crock of sh1te

 

Are any electrical loads drawn from the 12v battery while the vehicle is being driven in electric locomotion mode?

 

If so and if they are significant ones and if the charging of the 12v battery while plugged into the mains charger is a slow trickle charge then I could imagine a situation where a top up after a short run like 21 miles to charge the main battery would not be long enough to recharge the 12v one.

 

Which would still be a C.O.S.