CTEK Battery Chargers.

[Jocko]

Charger screwed to the inside of the garage door, car connected up, and a red velcro flag attached to the top of the steering wheel to remind me. I have set up my dashcam in a house window that overlooks the drive in case any nerdo well wants to snip the cable!

[culzean]

Charger screwed to the inside of the garage door, car connected up, and a red velcro flag attached to the top of the steering wheel to remind me. I have set up my dashcam in a house window that overlooks the drive in case any nerdo well wants to snip the cable!

Often leave one or both of our cars connected up on driveway. The extension leads tend to be black and blend in well with the tarmac -  also have two CCTV cameras overlooking drive, one visible and one hidden LOL

[Jocko]

Unfortunately, the cable is red and black but there is a 6' hedge around our property and only the gate to break it so things are not that evident.

[Jocko]

I check the display every time I go in and out of the garage/workshop and it was sitting at 12.6v but this morning it was chilly and it was displaying 13.1v. Must put a trickle in on a cold morning.

[culzean]

I check the display every time I go in and out of the garage/workshop and it was sitting at 12.6v but this morning it was chilly and it was displaying 13.1v. Must put a trickle in on a cold morning.

The AA charger does have temperature compensation - and the colder the battery the higher the 'float voltage' needs to be.  Most smart chargers switch to 'float voltage' once bulk charging  is complete - float voltage can be 13.5 to 13.7 volts, depending upon ambient temperature.  Float voltage is supposed to keep battery in a charged state without actually charging it, a battery can be kept at float voltage indefinitely without damaging it.

[Jeff B]

I have a 2017 Jazz CVT. I am concerned that since COVID we are only doing very short journeys and the battery is probably not being sufficiently well charged. Having been in the situation in the past with a Mk2 CVT where the battery suddenly died and left us stranded, I am not keen to repeat the experience, especially as the Mk3 has the stop/start feature. (I always turn off that off now btw).

The handbook says that the battery has to be disconnected before attaching a battery charger. I used to charge my previous Jazz (Mk2 CVT) using my ancient battery charger with the battery still connected with no problems. I have just bought one the newer "smart" trickle battery chargers (NOCO Genius 5 amp) so that there should be no danger of overcharging. I am reluctant to disconnect the battery as won't there be all that business of radio codes etc? Or maybe worse things with all the additional technology in these later models?

What do others do when charging their batteries? Any advice appreciated please.

[UKjim]

No need to disconnect the battery whilst using your smart battery conditioner, it will be perfectly OK.


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[Neil Ives]

Something every user of the modern CTEK type battery chargers needs to know is that they will not charge a completely discharched battery. They appear to need to know the battery voltage before they set themselves up for charging. I had a completely flat battery on a previous car. My CTEK charger would not work. I had to go onto a local FaceAche page to ask if someone would lend me a traditional transformer type charger. After an overnight trickle charge I took the borrowed charger back, (along with some nice biscuits) and the CTEK charger worked ok.

[culzean]

Something every user of the modern CTEK type battery chargers needs to know is that they will not charge a completely discharched battery. They appear to need to know the battery voltage before they set themselves up for charging. I had a completely flat battery on a previous car. My CTEK charger would not work. I had to go onto a local FaceAche page to ask if someone would lend me a traditional transformer type charger. After an overnight trickle charge I took the borrowed charger back, (along with some nice biscuits) and the CTEK charger worked ok.

You can connect a partly charged 12v battery in parallel with the completely flat one and it will start charging, ( it just needs to see at least 9 volts IIRC ) you can then disconnect the donor battery after a while.  The 'voltage sensing' before power is applied is down to the anti-spark and anti-reverse charging fool-proofing safeguards built into modern chargers,  but as usual 'old tech' still comers in useful ( as long as you have some idea of what you are doing and don't need wrapping in cotton wool ).

Also you can get Lithium Ion batteries for motorbikes,  you can use a normal 12volt lead acid charger as long as it does not have a 'de-sulphate'  program step ( like some CTEK have ) - this apparently applies over 15 volts to battery and will damage a Li-Ion battery,  which should not see more than about 14.4v.   

I have found that a lead acid battery that has been allowed to go completely flat is damaged anyway,  and time for a new one...

[culzean]

What do others do when charging their batteries? Any advice appreciated please.

Never in my life disconnected a battery to charge it, even when using the old 'dumb' chargers.  The cars system will easily stand 15 volts without damage, some older chargers can be up to 18 volts 'open circuit' ( nothing connected to the clips ) but that is clamped down once the battery is in circuit, modern chargers have much better voltage regulation and are safe.

[ericrw]

A 2017 Jazz CVT does not need codes to reinstate radio after disconnecting battery !

[Jeff B]

What do others do when charging their batteries? Any advice appreciated please.

Never in my life disconnected a battery to charge it, even when using the old 'dumb' chargers.  The cars system will easily stand 15 volts without damage, some older chargers can be up to 18 volts 'open circuit' ( nothing connected to the clips ) but that is clamped down once the battery is in circuit, modern chargers have much better voltage regulation and are safe.

Me neither, but I am used to cars which were a lot simpler with far less electronic gizmos than today's models! Having had a very expensive problem with an ECU on my last Jazz (not related to battery charging though btw) I am extremely wary of using a battery charger with our Mk3 Jazz in case I inadvertently do some mischief! It's only because we aren't doing any long journeys that the issue of battery charging has arisen.

Having studied other threads on the forum I now realise that I don't know what type of battery I have either, and the NOCO charger requires me to select the type before I connect it! It looks like a bog-standard lead-acid to me but there are no visible labels. I would have to take the battery out if I want to find any labels that may be on the sides - the very thing I am trying to avoid....aargh!

[Jeff B]

A 2017 Jazz CVT does not need codes to reinstate radio after disconnecting battery !

That's interesting - thanks. Are there any other potential risks do you know e.g. loss of computer memory leading to other issues?

[Kremmen]

I've CTEK my MK4 twice without any issues.

[Neil Ives]

You can connect a partly charged 12v battery in parallel with the completely flat one and it will start charging, ( it just needs to see at least 9 volts IIRC ) you can then disconnect the donor battery after a while.

Well, I thought if that and tried paralleling with an old battery that I have that still seems to hold a charge but it didn't work. The spare battery may have been too flat to do the job.