CTEK MXS 5.0 Battery Charger

JeffL · March 28, 2020

I'm about to buy the above charger. (Highly recommended on here and elsewhere).

Question 1. Do you know if the Direct Connector Adaptor with ring eyelets supplied with the charger is the CTE-56261(8mm), i.e. 8mm (M6) ring eyelets?

(I just had a look at the Battery connections on my GS300 and on our Honda Jazz and they look like 8mm (M8) screws. CTEK also offer a 6mm (M6) ring eyelet screw size version, on amazon, but I would imagine that most batteries are fixed with the bigger 8mm screw size. I'm going to order an extra adaptor so that I can fit one to each car.)

Question 2. Will it be okay to connect the negative/earth of the Direct Connector Adaptors permanently to the negative/earth of our car batteries rather than the body of the car(s)?

(On reading the reviews on amazon it appears that the instructions say to connect the negative/earth of the Direct Connector Adaptor to the body of the car and not the negative/earth of the Battery. It would be so much easier (for me!) to connect to the Battery, would that be ok? It's what I've always done over the years when charging our car batteries.)

IF your advice is to definitely connect to the body of the car, where is the best place? The negative wire on the GS300 disappears somewhere below the Battery holder and would be difficult for me to access.

Thanks in advance.

Herbie · March 28, 2020

I don't know how much adapters are but there's no need to go to the expense of buying two - just cut off the original ones if they're the incorrect size and just crimp or solder new eyelets of the correct size on.

Yes, perfectly fine and acceptable to connect both positive and negative directly to the Battery - that's exactly what I did in my RX as you'll see below:

RgrWynne · March 28, 2020

I also connected to the Battery terminal points, absolutely no problems

JeffL · March 28, 2020

Thanks Herbs and Roger. That's a relief that I can connect to the Battery.

I should only need to buy one adaptor for the second car as one comes with the charger. Below is the amazon link for the extra one at £8.76.

https://www.amazon.co.uk/gp/product/B002OHN5NQ/ref=ox_sc_act_title_2?smid=A3P5ROKL5A1OLE&psc=1

Thanks again, very prompt replies!

JeffL · March 29, 2020

About to show my ignorance re cars! Will anything become disconnected and need resetting if I remove the nuts on the Battery terminal clamps so that I can attach the CTEK Direct Connector Adaptor? The other option is to buy some new M8 nuts and attach the adaptor without removing the existing nuts as the screws are just about long enough. The question then is should I buy regular A2 stainless steel nuts or A2 stainless steel nylon insert locking nuts?

Herbie · March 29, 2020

2 hours ago, JeffL said:

Will anything become disconnected and need resetting if I remove the nuts on the battery terminal clamps so that I can attach the CTEK Direct Connector Adaptor?

Not if yours is like mine. The main cable is crimped into the clamp that goes around the Battery post, so you can actually unscrew the nut and take the bolt right out without the clamp losing contact with the Battery post. Put the bolt through the CTEK eyelet then back through the clamp, screw the nut back on and Robert is your mother's brother.

JeffL · March 29, 2020

Bob's your uncle!!!!!!!!!!!!!!!!!!! Thanks Herbs

JeffL · March 31, 2020

OK, so my car is now on SORN, Battery charger bought and connected. Photos attached. Thanks for the help and advice

Vlady · March 31, 2020

@JeffLI received my CTEK 5 a few days ago, I should get it long time ago as it is a very nice and good piece of kit!

I reconditioned my GS Battery too!

RgrWynne · April 1, 2020

I know there is a reconditioning mode on the CTek, but I have always been very suspicious of how effective this process is. As I really rely on my Battery, and on other engine driven products I have owned, to be completely reliable, I kinda think that once a Battery is finished it can’t really be brought back to being totally reliable. I stand to be corrected and hope yours is ok and will watch with interest the result, cheers, Roger

JeffL · September 15, 2020

Update: I put my car on SORN at the end of March. Garaged, full tank of petrol, parking brake off, tyre pressures increased to 40 psi, fully comp insurance changed to fire and theft and I connected my new CTEK MXS 5.0 Battery charger to the car. So for the last 5 months we've been using my wife's Jazz for the very few trips we've made during these unprecedented times. This Monday I taxed the car and reinstated the fully comp insurance. Disconnected the CTEK, sat in the car and thought, wow, I've missed you! Now for the moment of truth, I pressed the start button and it started immediately, no hesitation at all. Took it out for a run yesterday and again today and it drives just like it always has done. So being in hibernation for 5 months doesn't appear to have done it any harm. Thanks to those on this forum who recommended the CTEK MXS 5.0.😀

Question: I did take the CTEK off the Lexus for a few hours one day to give the Jazz Battery a charge and although I have the CTEK 2.5M extension attached it would only just reach the mains socket (The Jazz's home is a carport attached to the garage). I can manage with this, just about, but thought it would be far more convenient to use two x the CTEX 2.5 M extensions instead of considering using a 240 volt extension reel. So I sent an enquiry to CTEK as follows. Is it okay to use 2 x your 2.5M extension cables together to create 1 x 5m extension when using the CTEK MXS 5.0 Battery charger? Their reply is as follows.

No, not to recommend, as the resistance will be quite high so the charge that reaches the Battery no longer is as we want it to be.
Extend on the mains side, if possible!

Med vänliga hälsningar,
Yours, faithfully,

Teresa

SUPPORT TEAM

I thought this might be of interest to anyone on this forum considering doing this. Also, would you agree with what they've said? Thanks.

JeffL · September 16, 2020

Bump

NemesisUK · September 16, 2020

I had my CLS55 permanently on charge with the CTEK living in the boot and the mains cable trailing out through the boot seal. To connect to the mains I had a 20m extension cable fitted with a weatherproof 13amp socket, the CTEK plugged in and the socket dangled just off the ground behind the car. All through the foulest of weathers, no issues at all, just a fully charged Battery and a happy car.

Herbie · September 16, 2020

I haven't got a CTEK charger so I don't know the cross-sectional area of the output cable and therefore can't calculate the voltage drop for a 5m run as opposed to a 2.5m run.

There will be a known volt drop per Amp per Metre for the size of cable so yes, it is possible that by doubling the length of the cable then the permissible voltage drop will be exceeded.

If someone who has one of these chargers can get the cross-sectional area of the output conductors then the voltage drop should be obtainable by using the voltage drop calculator here: https://www.12voltplanet.co.uk/cable-sizing-selection.html

JeffL · September 16, 2020

1 hour ago, Herbie said:

I haven't got a CTEK charger so I don't know the cross-sectional area of the output cable and therefore can't calculate the voltage drop for a 5m run as opposed to a 2.5m run.

There will be a known volt drop per Amp per Metre for the size of cable so yes, it is possible that by doubling the length of the cable then the permissible voltage drop will be exceeded.

If someone who has one of these chargers can get the cross-sectional area of the output conductors then the voltage drop should be obtainable by using the voltage drop calculator here: https://www.12voltplanet.co.uk/cable-sizing-selection.html

I knew you'd know how to find this out Herbs. I of course have the charger but no idea how to perform the calculation as per the link you attached. Hopefully someone else on here will be able to do it. I was surprised that you don't have a CTEK but then remembered you've got a Hybrid and you'll just use your booster pack if/when necessary.