Ctek Battery Charger & Negative Connection to XC60 Chassis

[RS3100]

Originally Posted by 100K+

So when down the line the Volvo owner finally has to change the battery ( after 7 +yrs?? ) as soon as they connects the new fully charged battery, on first start up they are greeted by "confusing warning messages"??? ( which can only be cleared by a dealer VIDA/DICE????)
I'm with SwissXC90 on what he says about connections, but I'd just connect to engine bolt if the negative terminal was difficult to get to.

A worrying part about running these "modern" vehicles is that using some of the "first principals" I leaned 40 years ago are sometimes the quickest ways to scrap components in these modern cars

Cheers
Bob

I'm not sure about confusing warning messages, but it may well disable the start/stop system and affect some other functions until the BMS has restabilised.

VIDA states not to connect directly to the battery negative pole for that reason.

Following a battery replacement, the BMS should be reset through software, although I believe it can also be achieved by leaving the car locked and unused for 6 - 8 hours.

At my last dealer service, the technician attached the battery support unit directly to both battery terminals (contrary to the instructions in VIDA). I had a "start/stop" unavailable message all the way home, but it disappeared and the start/stop system was working again the next day after the car had been parked overnight.

[HDAV]

Not a charger, but jump started a lady in a clio the other week, she had some jump leads..... looking at the engine there is a braded earth strap to the left of the engine (in front of steering wheel on a right hand drive car) just in front of the scuttle panel with a nice looking stud you can fit a a ring terminal too.....will need to extend the standard ctek leads though

Do you have tow bar? https://www.mobilecentre.co.uk/ctek-...-towing-socket

[GrahamHR]

There is nothing mysterious about connecting chargers and jump start leads. Positive to positive, negative to negative. Yes, if Volvo fits a sensor on the negative side to monitor charge status, what a stupid thing to do really; What is the point of doing it that way rather than on the +ve side ? Current in and out of the battery is the same whatever terminal its measured from.

[Zebster]

Originally Posted by GrahamHR

There is nothing mysterious about connecting chargers and jump start leads. Positive to positive, negative to negative. Yes, if Volvo fits a sensor on the negative side to monitor charge status, what a stupid thing to do really; What is the point of doing it that way rather than on the +ve side ? Current in and out of the battery is the same whatever terminal its measured from.

When the sensor is on the negative (as it is with our cars) then you can clip the charger negative lead onto the chassis or engine to ensure the current then flows through the sensor... if the sensor was on the positive lead you'd then struggle to find somewhere to attach the charger positive lead!

[Zebster]

Originally Posted by 100K+

So when down the line the Volvo owner finally has to change the battery ( after 7 +yrs?? ) as soon as they connects the new fully charged battery, on first start up they are greeted by "confusing warning messages"??? ( which can only be cleared by a dealer VIDA/DICE????)...

Yes, that's correct. However if you didn't reset the BMS then the system would eventually relearn the battery state of charge anyway and so then stop giving incorrect messages about the battery still having a low charge. Same as if you just plonk the charger onto the battery terminals and bypass the sensor.

Not understanding how the system works is no reason to ignore the instructions given in the manual.

[Tannaton]

Originally Posted by GrahamHR

There is nothing mysterious about connecting chargers and jump start leads. Positive to positive, negative to negative. Yes, if Volvo fits a sensor on the negative side to monitor charge status, what a stupid thing to do really; What is the point of doing it that way rather than on the +ve side ? Current in and out of the battery is the same whatever terminal its measured from.

Because there are far more places to clip on to in order to get a negative connection. If the sensor was on the live side there are much fewer places and they’re all insulated.

[Mick787]

Originally Posted by Zebster

Seems like a lot of trouble when you can more easily clip the negative lead onto the engine?

The dealership fitted the charging tail for me at no charge when I bought the car. I've just let Samball know an answer to his question.

Yes Samball, I'll get the images sorted for you and send you a p.m when sorted, it is a very easy job.

[RS3100]

Originally Posted by Tannaton

Because there are far more places to clip on to in order to get a negative connection. If the sensor was on the live side there are much fewer places and they’re all insulated.

Exactly. Plus whichever of the battery posts the shunt is connected to, if you connect the charger leads directly to both battery posts you are bypassing the shunt and the BMS will not see the charge, so it's interpretation of the battery SOC will be wrong. When you connect the negative lead to a remote earthing point the shunt is in circuit as intended and the charging input is detected.

[Tannaton]

Originally Posted by RS3100

Exactly. Plus whichever of the battery posts the shunt is connected to, if you connect the charger leads directly to both battery posts you are bypassing the shunt and the BMS will not see the charge, so it's interpretation of the battery SOC will be wrong. When you connect the negative lead to a remote earthing point the shunt is in circuit as intended and the charging input is detected.

The other issue is the positive batter feed immediately splits into two fuses, one for the starter\alternator circuit and the other for everything else.so there’s no place to fit a shunt without a redesign of the heavy current side.

[samball]

Originally Posted by Mick787

The dealership fitted the charging tail for me at no charge when I bought the car. I've just let Samball know an answer to his question.

Yes Samball, I'll get the images sorted for you and send you a p.m when sorted, it is a very easy job.

Received your pm and unable to reply as I have less than 30 posts.
Images are not displayed as the link is referenced to your desktop.