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Mk4 negative for charging


jmkgreen
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My 2019 Focus is mainly inactive for long periods so I bought a ctek mxs 5 to keep the battery in good condition. My question concerns the negative connection.

I have attached the eyelets to both battery terminals (1st pic) yet the instructions note that the negative should be connected away from the battery.

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I can see a ground cable attached to the chassis (2nd pic) but this is covered in plastic that is itself caught under large plastic covers. Is there a convenient alternative to this? Is the advice even relevant on newer models?

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The plastic cover in the 2nd picture is easily removable by undoing the clips. Underneath it you will find a large amount of unwanted debris that accumulates behind the wing and obstructs the rainwater from draining away like it's designed too. 

If you haven't removed this since owning the car then I'd be inclined to do so and check. I did mine on both sides last year and removed a good few handfuls of leaves twigs and crap. 

If you pour water down the windscreen it should almost immediately drain out from under the front wheel arch is a good idea to see if there is any obstruction.

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It's more important on newer models to use the earthing point you have identified, it's due to the BMS, so I'd recommend doing it that way.

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The negative charging lead is in the wrong place. It should NOT be connected to the battery negative terminal.

The negative charger lead should be connected to the vehicle main chassis earth point. With the negative lead connected direct to the battery terminal the BMS (battery Monitor System) will not know the battery has been charged. This will then lead to the SOC being incorrect.

 

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29 minutes ago, unofix said:

Hi Shane, Happy New Year.

So to answer the problem of why the keyless entry is not working. The problem is the SOC (State Of Charge) of your battery. You can go for a drive of a thousand miles and it will not guarantee that your battery will have reached the necessary level.

Your car is equipped with a smart charge system (but it's not as cleaver as it thinks it is) which means that it will only charge your battery to a maximum SOC of 80% (factory default for UK vehicles). Now at this time of year with headlights, wipers, heated seats, heated screens etc, etc, then the poor battery struggles to say charged. Once the SOC falls below 70% the the car stars to disable various equipment to save power, so first to be disabled is the heated front screen (after all why would you want to use that in the middle of winter ?). Now when the car is parked and it needs to save battery power then it turns off keyless entry. At first it just disables the two rear doors and the passenger door, but if further savings have to be made then it will eventually turn off keyless entry on all doors.

To fix the problem you need to put your battery on charge every 3 to 4 weeks. Yes it's a pain, but it's all in the name of allegedly reducing emissions and saving the dolphins.

The correct method to charge your battery is very important. Leave the battery connected on the car and connect a smart battery charger. The positive lead needs to be connected directly to the battery terminal. The negative lead must be connected to the vehicle main ground point on the chassis (near the battery). Do NOT connect the negative lead direct to the battery terminal otherwise the BMS (Battery Monitor System) will not know the battery has been charged.

Finally all this messing about can be avoided by using the software FORScan and using it to set the SOC of your car to 90 or even 95% (like mine) and your battery will get charged by the car and live happily ever after. The End ! 

 

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Had another look. That plastic cover is well wedged in place between the bit covering where the windscreen wipers are attached and the bodywork.

I did manage to prise it open enough to attach a socket and managed to begin undoing it - but then sparks flew… did I miss a step here? Was I supposed to disconnect something first?

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@Unofix is entirely correct!! On my old Mk2, when charging, I just connect the charger +ve to battery +ve, and charger -ve, to battery -ve  terminal BUT, my car is far too old to have a BMS, unlike yours so that's why I can do it, and you can't. (The BMS is hat metal box about the size of a box of matches attached to your battery -ve terminal)

I'm pretty sure the -ve terminal of your charger can be connected to any solid bolt that pierces into the metal of your car's body.

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I've not bothered with the eye clips and use the crocodile clips provided instead not sure if the Ctek comes with those clips although I would presume they would.

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2 minutes ago, Wino said:

I've not bothered with the eye clips and use the crocodile clips provided instead not sure if the Ctek comes with those clips although I would presume they would.

I have the crocodile clips but I assume this would suffer the same problem as the eyelets - after all surely the charger doesn’t which which connectors were used?

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Just now, Wino said:

I've not bothered with the eye clips and use the crocodile clips provided instead not sure if the Ctek comes with those clips although I would presume they would.

If it's the only car that will be used with that charger, it's often very handy to permanently attach a  'fly lead' like I did which often comes with it...

2037726158_flyleadconnection.thumb.jpg.3f55ce73f8eaffb535d5aec1039e9ec9.jpg

 

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15 minutes ago, jmkgreen said:

I have the crocodile clips but I assume this would suffer the same problem as the eyelets - after all surely the charger doesn’t which which connectors were used?

On the Mk4 there is a good contact point for the negative clip just to the left of the passenger headlight. It's easily recognised as it stood up tall on it's own with a circular void.

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17 minutes ago, StephenFord said:

If it's the only car that will be used with that charger, it's often very handy to permanently attach a  'fly lead' like I did which often comes with it...

2037726158_flyleadconnection.thumb.jpg.3f55ce73f8eaffb535d5aec1039e9ec9.jpg

 

That set up is fine unless you have the Mk4. Not many places within the engine bay to fit the fly lead as it cant go on the negative terminal. 

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16 minutes ago, StephenFord said:

If it's the only car that will be used with that charger, it's often very handy to permanently attach a  'fly lead' like I did which often comes with it...

2037726158_flyleadconnection.thumb.jpg.3f55ce73f8eaffb535d5aec1039e9ec9.jpg

 

This is exactly what I am trying to fit.

It seems the mk3 Focus has a ground point exposed? The mk4 has it covered and is a right pain to access.

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11 minutes ago, Wino said:

On the Mk4 there is a good contact point for the negative clip just to the left of the passenger headlight. It's easily recognised as it stood up tall on it's own with a circular void.

Would you want a fly lead to be crossing the engine bay that much? Without checking I’m not sure if the cable would reach tbh.

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Just now, jmkgreen said:

Would you want a fly lead to be crossing the engine bay that much? Without checking I’m not sure if the cable would reach tbh.

It doesnt cross the engine bay as such. The negative clip is 6 inch lower towards the headlight if that makes sense. 

Had it on earlier today. No issues at all. You can even put both clips sideways on and if you put a sponge under the bonnet where the bonnet latch is you can lower the bonnet right down so it's not stuck up in the air all day.

I posted a picture earlier today after I'd put a security camera up and you can just see the charger sat on the windowsill so I can read it from inside the house. Lol.

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1 hour ago, jmkgreen said:

I did manage to prise it open enough to attach a socket and managed to begin undoing it - but then sparks flew… did I miss a step here? Was I supposed to disconnect something first?

Yes you missed the step of disconnecting the negative battery terminal lead 'before' disconnecting the main chassis earth. For ease you could disconnect the positive battery terminal BUT make sure to keep it away from the battery terminals while you are working on the chassis earth lead.

I'm not sure why you can't get the plastic cover out of the way, I know I've had it removed on my 2019 Mk4 Focus, and I don't remember it being difficult.

 

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51 minutes ago, unofix said:

Yes you missed the step of disconnecting the negative battery terminal lead 'before' disconnecting the main chassis earth. For ease you could disconnect the positive battery terminal BUT make sure to keep it away from the battery terminals while you are working on the chassis earth lead.

I'm not sure why you can't get the plastic cover out of the way, I know I've had it removed on my 2019 Mk4 Focus, and I don't remember it being difficult.

 

The cover has an easy to remove clip but appears clipped into the larger facia further up (which seems to be a push fitting). I get very little wiggle room - it’s a tiny bit underneath the larger facia to the left yet fully underneath the chassis on the right. My experience of these things are that they snap when wiggled too much!

 

I will don some latex gloves tomorrow and tighten back the ground nut as I I had to leave the “project” what with fading light and small children about this afternoon. I think it will have to be crocodile clips.

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Got my Noco fly lead attached today but had the same problem as @jmkgreen finding a suitable earthing point.

I also had to slightly modify the battery positive terminal cover so it would still lock into place after the fly lead was connected.

IMG_1927.thumb.jpeg.6a0854f695c7d24b4dde1e8e966f9117.jpeg IMG_1930.thumb.jpeg.2f691cb4f0a5c23443b0db063953691f.jpeg

The Noco lead comes with M6 eyelet terminals and the only easily accessible earthing points on the Focus are M10 bolts.

After a good look around I found two suitable earthing points under the airbox. Thankfully the airbox is quite easy to remove.

IMG_1933.thumb.jpeg.d7025daf748281addf4d2b1767759c71.jpeg

So it was a bit of a faff but finally fitted and quite neat in the end.

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Incredible isn't it that we need this thread.

I've read elsewhere on this forum that the battery doesn't get charged above 80% (in which case why have a 70ah battery instead of a 56ah one that will be smaller, lighter and cheaper and charge it up to 100%?).

Anyway, I have to keep charging my MK4 battery regularly using the CTEK for the stop-start to work. And no, it isn't short journeys, excessive use of demisters etc. and I've even turned the auto-mirror folding and other leccy stuff off.

I last had to keep charging a battery in this way when my 10-year old battery on my Mazda was on its way out, and prior to that, not for 40-odd years when I drove old bangers! Hardly an improvement and hence my reason for the initial comment above.

To me that ain't right and, in the face of "its all OK sir" from the dealership I'm in process of composing a query to Ford customer services dept to see where that gets me.

I have an ulterior motive for this, even if it gets me nowhere - you could say the reason for contacting Ford could be "political"! Essentially I bought the car (a 70 reg) a couple of months ago and will be having a towbar fitted soon. If there are continuing issues, I want to ensure that neither Ford nor the dealership can point to the towbar and claim that its electrics are causing the problem, 'cos I'll have the problem well and truly documented and dated. (I had that "discussion" with Vauxhall a few years ago when the rear lamps kept blowing on a 6-month old Astra).

BTW I also use a CTEK, it was bought to keep the caravan battery topped-up in the garage during the Winter when the 'van is laid up.

Post-warranty I'll be looking at the Forscan "fix" recommended elsewhere. Having said that I was reading recently an assessment of an electic car as a towcar, and was shocked to see the assessor pointing-out that it is recommended that the cars batteries are not fully charged 'cos that can shorten the battery life - quite the opposite of what I've always believed to be the case. Makes me wonder what the heck is going on with battery tech.

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49 minutes ago, RMurphy195 said:

and was shocked to see the assessor pointing-out that it is recommended that the cars batteries are not fully charged 'cos that can shorten the battery life - quite the opposite of what I've always believed to be the case.

I do wonder if there is any truth in this "not fully charged 'cos that can shorten the battery life" because like you I have always been told that it is better to fully charge and discharge batteries in order to get the best life expectancy from them.

Is it in fact that because it takes a lot longer to put the last 20% charge in to the battery that the "Tree Huggers" don't want people to use the 'extra' electricity ?

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18 minutes ago, unofix said:

I do wonder if there is any truth in this "not fully charged 'cos that can shorten the battery life" because like you I have always been told that it is better to fully charge and discharge batteries in order to get the best life expectancy from them.

Is it in fact that because it takes a lot longer to put the last 20% charge in to the battery that the "Tree Huggers" don't want people to use the 'extra' electricity ?

TBH I don't give a rats posterior - the car is advertised as having certain facilities, somewhere in the 500-odd page manual I've read that I needn't worry about battery drain for the stop/start 'cos the system is designed for it and in my book if the car has not been put together with that info in mind there is a question over things like "fit for purpose" and "trades description". Let alone the much vaunted heated screen!

(Page 158 "Your vehicle has an enhanced battery and starter motor that are designed for an increased number of engine starts")

Rant over, sorry .

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16 hours ago, RMurphy195 said:

Incredible isn't it that we need this thread.

I've read elsewhere on this forum that the battery doesn't get charged above 80% (in which case why have a 70ah battery instead of a 56ah one that will be smaller, lighter and cheaper and charge it up to 100%?).

This is an intresting point.

I'm going to hook up to FORScan again tomorrow and look at the battery again.

Reason being I was noseying around yesterday in Forscan whilst it was charging and I never sort of twigged but I'm sure in the battery part it doesn't say 70ah it says 52ah. 

Is there a way of checking on Forscan without being connected directly to the car ? 

 

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Heres what I was on about in the earlier post.

It clearly shows up on Forscan as a 52ah battery.............

Screenshot_20220102-204427_Photos.thumb.jpg.5c1df88364a6cf5915f1616ba5886b6e.jpgScreenshot_20220102-204412_Photos.thumb.jpg.0f73964857447b38c60649237efa6852.jpg

 

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42 minutes ago, Wino said:

Heres what I was on about in the earlier post.

It clearly shows up on Forscan as a 56ah battery.............

Screenshot_20220102-204427_Photos.thumb.jpg.5c1df88364a6cf5915f1616ba5886b6e.jpgScreenshot_20220102-204412_Photos.thumb.jpg.0f73964857447b38c60649237efa6852.jpg

 

That is interesting. I wonder if it would charge more if you changed it to whatever size you have. 

The one fitted to my car is a 60/600.  If your one is a 70 then 56 is 80% of it as you probably already know. I don't have an extended licence at the moment so I can't check what mine has been factory set to.

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