CTEK MXS 5.0 Battery Charger

[Pally]

Hey, I'm looking for how to hook up the CTEK MXS 5.0 on my Ford Fiesta Titanium X 1.0. 

 

Unfortunately due to short journeys and not much use due to working from home, the battery is struggling to a point the car was completely dead. AA came out and confirmed it was charging and holding but could squeeze some more life out of it. In any event I need to learn to charge it to keep the battery topped up. 

 

So, I follow an American Youtube Ford Master Technician called FordTechMakuloco who demonstrates in real time how to properly charge so the BMS knows you are putting charge into the battery to allow e.g. stop start to work. He says the positive clip goes on the positive terminal but the negative clip goes on the other side of the battery sensor and not the negative terminal. Also he says no need to clip the negative clip to a body ground. Any advice would be much appreciated. However, others may disagree due to the risk of damage to the sensor. I appreciate any input on this. 

Also, the charger needs to charge for about 12 hours. I want to shut the bonnet and lock the car but worried the bonnet will pinch the cable and stop the charge. What have others done? I'm also looking at leaving the actual physical charger next to my tyre or park the car right up to my garage and place the charge in the garage with the cable coming out to the car. 

[unofix]

There is nothing magical about connecting any battery charger to your car battery.

Simply connect the positive lead (Red) to the battery positive terminal +

Connect the negative lead (Black) to the main earth point on the bodywork of the car (Do not connect to the battery terminal).

Turn on the charger and leave it for a full 12 hours (or longer), even if the charger is saying the battery is full.

 

[unofix]

[Pally]

Thank you for the reply and the picture. 

Is it okay to shut the bonnet with the cable coming out? 

 

 

[TomsFocus]

The charging cables are very thin and unlikely to get pinched as long as they're not right on a bonnet lip.  I would avoid putting it through the side of the bonnet where the sharp edge is.  Front is probably ok, though you'd have to double check.  Personally, I feed mine up towards the windscreen, where the rubber rain seal will flex around the cables and not damage them at all.  Just take care not to get them too close to the bonnet hinge which could easily slice them in half.  

I put the physical charger inside the car on the dashboard just in case it rains.  Again, the rubber door seal flexes around the cables as long as you take care when closing it.

[Pally]

Thank you so much @TomsFocus I will give it a go. I ordered a 2metre extension cable. In light of your advice. I will park the car close to the garage door and feed the extension cable through the top of the bonnet, down the wing and into the garage where I will store the charge itself and plug it into a socket. And also lock the door. This will hopefully allow me to charge the car all day without concerns of someone trying to knick my car or battery. The issue I have is I live on road commonly used by many with my driveway fully exposed from the left, right and towards the pathway. I don't want anyone getting funny ideas to mess around with my charger or car. 

[Jim H]

What is the reason behind connecting the negative cable of the charger (or good battery) to an earth point rather than the negative battery terminal? I'm sure in the past everyone used to connect battery to battery.

[TomsFocus]

12 hours ago, Jim H said:

What is the reason behind connecting the negative cable of the charger (or good battery) to an earth point rather than the negative battery terminal? I'm sure in the past everyone used to connect battery to battery.

That's fine for charging older cars batteries.  Modern cars use a BMS to determine battery charge, and then switch off certain consumers when the charge gets low (stop start, air con, keyless entry, etc).

If you charge the battery using the battery terminal, the BMS will not 'see' that charge put in, and will not reinstate the consumers that were switched off.  Using the chassis negative instead means that the BMS reads the charge put in and will reinstate those consumers as if the alternator had charged it.

(Having said that, I've read that the state of charge updates after about 48 hours if charged pre-BMS - but also seen a few cars where the state of charge is well off, despite not having been externally charged at all, so there's still some confusion around that at the moment.)

Regarding a jump start, it has always been best practice to use a chassis earth for that.  Chances are it'll spark on the final connection, so you want that as far away from the battery as possible.

[Eric Bloodaxe]

12 hours ago, Jim H said:

What is the reason behind connecting the negative cable of the charger (or good battery) to an earth point rather than the negative battery terminal? I'm sure in the past everyone used to connect battery to battery.

Yes, as Tom says, in the past we didn't have battery monitoring systems which can be fooled into indicating a false state of charge it the negative is connected directly to the battery negative terminal.

There have been a few threads on here now of cases where the SOC as indicated by a voltage reading from the battery differs from that shown by the dealer diagnistics, which we suspect may be a result of incorrect charging somewhere down the line.

 

 

[Pally]

@TomsFocus @Eric Bloodaxe I got my info regarding how to properly charge a Ford BMS battery from an American Ford Technician who now works independently. If you have some time, it would be great to get your views on the YouTube video titled “Ford BMS battery Monitoring System: How it Works and How to Properly Charge your Battery”. 

[Tizer]

I wonder if the Alarm will go off if the battery is charge with the door locked. 

I know that an unexpected Current Draw will set it off but I don't know if Charging will do the same. I would be interested in hearing your results @Pally,

[TomsFocus]

I've charged both a Mk4 Focus and Mk7 Golf with the door locked.

Only time the alarm went off is when I left the bonnet fully open.  That needs to be at least closed to the first latch.

[Eric Bloodaxe]

47 minutes ago, Pally said:

If you have some time, it would be great to get your views on the YouTube video titled “Ford BMS Battery Monitoring System: How it Works and How to Properly Charge your Battery”. 

That video has been reviewed on here a couple of years back: 

He's basically giving the same advice as on this thread, ie don't connect directly to the negative but makes it all sound rather complicated. Much simpler to just connect to an earth point.

In general, I'm always a bit wary of US videos (other than for interest) as even where US and European models look the same, they often differ significantly.

[Pally]

5 hours ago, Eric Bloodaxe said:

That video has been reviewed on here a couple of years back: 

He's basically giving the same advice as on this thread, ie don't connect directly to the negative but makes it all sound rather complicated. Much simpler to just connect to an earth point.

In general, I'm always a bit wary of US videos (other than for interest) as even where US and European models look the same, they often differ significantly.

Thank you for input. Really appreciate it. I'll give it a go once my extension lead arrives.