Connecting CTEK/Battery Tender

[bfets]

cool thanks, I was just hoping to use the other side at it suits me better in the garage. I'm guessing there must be one as the fuse box will ground somewhere over there as well

Yeah for sure. If you go digging, I'm sure you'll find another decent ground to use on that side.

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[DFB5.0]

Has anyone used a Bluetooth battery condition monitor. These connect to the battery terminals and alert you via your phone when the battery charge is down. I have a client who swears by them, which he has installed on a Landcruiser which is only occasionally driven.

SCA 12V Wireless Battery Monitor | Supercheap Auto
Dual Battery Monitor - Bluetooth App Based-AUSSIE DRIFTER TOURING
Amazon.com.au : bluetooth battery monitor

 

[bfets]

Has anyone used a Bluetooth battery condition monitor. These connect to the battery terminals and alert you via your phone when the battery charge is down. I have a client who swears by them, which he has installed on a Landcruiser which is only occasionally driven.

SCA 12V Wireless Battery Monitor | Supercheap Auto
Dual Battery Monitor - Bluetooth App Based-AUSSIE DRIFTER TOURING
Amazon.com.au : bluetooth battery monitor

I havent used something like that before. Didnt even know they exist to be honest. For my use case, the Ford App's alert that its disabling comms due to low battery is enough.

 

[OzzieRoss]

There isn't one by the fusebox, as our cars has that jump stud moved over to the passenger side. This is why I simply attached the positive of the charger lead to the positive pole of the battery as per my photos. Thats worked well for me.

I do the same as bfets, basically because the wires on my charger are not long enough to reach the fuse box and the earth stud, as they are on opposite sides in the engine compartment.

Note that the picture shown has the battery and the stud on the same (right hand) side. Hence, that's for a left hand drive car. For the right hand drive cars, the battery and the stud have been mounted on the left hand side. So in both cases on the passenger side The fuse box in the LH drive and RH drive cars is on the RH side of the engine compartment, so not moved.

 

[LouG]

My bike battery was the 2014 original when I sold the bike in 2023, and still going strong. It lived on a battery maintainer.
If I haven't driven my car for two weeks it gets a top up charge just to be safe.
Look after your batteries and they'll look after you.
Useful advice for all sorts of household appliances.

 

[5.0ALM]

Now a member of the CTEK club.

This arrived last Friday.
Unlikely to get the chance to play with it for a few weeks, being away with work.

Oh... the irony.

 

[5.0ALM]

The supplied M6 eyelet connectors that come with the MXS 5.0 charger are just perfect for the M6 studs on the Mustang!

No more of these notifications after a few weeks of not being driven!

Here's my install.

 

[DFB5.0]

The supplied M6 eyelet connectors that come with the MXS 5.0 charger are just perfect for the M6 studs on the Mustang!

No more of these notifications after a few weeks of not being driven!

Here's my install.

Thanks for the video, I actually needed to watch this to double check my installation was correct regarding the BMS. Turns out my older CTEK 3.6 is not working as it should and hasn't been charging properly. Swapped it to the newer MXS 5.0 and I'm back in business.

I'm probably scared from previous trauma in this department, but I would also look into getting some sealant for the negative terminal.

CRC Battery Terminal Protector 300g - 5098 - CRC Chemicals | Repco Australia

 

[OzzieRoss]

The supplied M6 eyelet connectors that come with the MXS 5.0 charger are just perfect for the M6 studs on the Mustang!

No more of these notifications after a few weeks of not being driven!

Here's my install.

In essence, I have the same install albeit with a NOCO 5 charger. I still get the notification after two weeks of not driving the car. It reminds me to drive the Mustang more often

 

[LouG]

I forgot about this thread and started another in the US section. I got this reply

"When the vehicle is powered off, the Body Control Module (BCM) runs a routine which confirms the battery's State of Charge (SoC). When the vehicle is in operation, the BCM monitors the interaction of the alternator, Powertrain Control Module (PCM) and various loads. In general, the Battery Management System (BMS) is like the Oil Life Monitor (OLM), but for the battery.

Tenders can be installed and used without interfering with BMS. Problems often occur when attachments are made directly to the battery; this can bypass the Hall Effect sensor located on the negative battery cable. The Hall sensor is what monitors the battery's SoC, charge and discharge of the battery.

While the positive tender lead (+) can be attached directly to the battery or fuse panel position, the negative tender lead (-) should be attached to a chassis ground. Most tie it down on the strut tower ground.

By attaching to a chassis ground, the electrons leaving the tender and being sent towards the battery must take the path involving the Hall sensor. This allows the BCM to correctly monitor the charging and SoC of the battery.

Edit,

Two examples.

In the first, tender leads are attached directly to the battery posts. Electrons leaving the tender and going into the battery are not accounted for by the BMS. Further, the charging current on the battery side of the system could be believed by BMS that the battery is discharging.

In the second, (+) tender lead is on the battery, while the (-) is on the chassis. Now, any electron movement is accounted for by BMS. In a sense BMS sees this charging force just like it does when the alternator is charging the battery."

I'd prefer to use the fuse block positive terminal and find an earth.
Any reason why not?

 

[insaneBoredom]

I use the post on the fuse box for the positive and the negative post on the body. Spray with some terminal protector and it was charging fine.

 

[5.0ALM]

Today is day #16 of our trip around Morocco, and to my surprise, a new notification appeared in the FordPass app overnight.

Surprised, because I had the CTEK 5.0 charger hooked up and running before leaving.

Prior to rigging up the CTEK charger I would get ~ 2 weeks of non-driving before receiving this notification. It seems there has been little to no benefit so far.

When I get home next week, I will have to resist the urge to take it for a drive ASAP, and hook up the DMM in-line with the charger O/P to see what the charge current is when floating on step 7, as it doesn't appear to be doing much at all.

If someone else has a DMM and can measure the current whilst on step 7, that would be appreciated. ie; disconnect either lead and hook the DMM in-line and wait for it to reach step 7 again, and note the charge current. By sharing results we will all know what to expect.

The whole point of the CTEK charger was to avoid getting this message.

Either the CTEK charger is not performing as expected, or the battery is failing and not holding a charge like a ~16 month old battery should. (Assuming it was manufactured Q2 of 24).
Not that I've even had an issue starting the car days after receiving the notification, but....

 

[bfets]

I've seen the same thing. I get the message exactly 2 weeks after the last drive. CTEK connected or not. The charger is working, because there's zero struggle when starting it, so the battery is not low. I've been wondering if it's purely time based, and it doesn't take battery charge into account at all.

 

[OzzieRoss]

Same here, although I use a NOCO charger. The point of connecting a (trickle) charger is to keep the battery full during extended periods of not driving the car. It does exactly that, but unfortunately the BMS doesn’t recognise that the battery is being kept full, hence you will still get the “dreaded” message after about two weeks of not driving the car.

 

[Starship Enterprise]

Same here, although I use a NOCO charger. The point of connecting a (trickle) charger is to keep the battery full during extended periods of not driving the car. It does exactly that, but unfortunately the BMS doesn’t recognise that the battery is being kept full, hence you will still get the “dreaded” message after about two weeks of not driving the car.

That’s interesting because the manual clearly states to not go more than 2 weeks without at least starting the car and putting the gear shift through it’s motions.
Page 327 of my 2025 manual.

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