Connecting a CTEC MXs 5.0

[Mr Billiards]

I have purchased a CTEC MXs 5.0 to use on my 2ltr Corolla while away on holiday for two weeks.

I would like to confirm if its ok to connect the CTEC clamps directly to the positive and negative Battery terminals while the Battery is in situ  and fully connected to the car.

As far as I can see the Battery is just a standard 12V battery and not an AGM battery?

 

 

[Corolly Poly]

Yes

[yossarian247]

Yes its fine to connect directly to the terminals whilst connected to the car, and yes it's a standard flooded Battery not an AGM.

[Mr Billiards]

Thank you for the information, much appreciated 👍

[Gray86]

CTEK doesn’t go directly onto negative terminal, that goes to an earthing point on the car. When I had my 2.0 (my dad does same with his 2.0 CHR) we used the positive terminal under the bonnet in the fuse box, and negative onto bare metal in the engine bay 

[Tommy X]

Most modern cars have a Battery monitoring system attached to the Negative terminal so I always use a chassis earthing point from the Battery to connect the charger negative lead 

 

[AndrueC]

I'd be surprised if our hybrids have a BMS for the 12v system. Certainly not one as suggested in that video. The state of the 12v Battery on our hybrids is unlikely to be taken into consideration by the ECU when balancing vehicle emissions.

I'd also suggest that the plethora of complaints from owners who have suffered a flat 12v Battery make any kind of 12v BMS highly unlikely. 

Indeed the impression I have is that the 12v Battery is left to fend for itself and largely ignored by the ECU (it almost seems to have been forgotten about by Toyota, lol). The idea that there is something in the car monitoring its health and trying to optimise its use seems unlikely.

[Derek.w]

Unlike the vidio I bet the electronics realise the Battery has been charged within seconds of starting.

A lot ou us use a seperate BM monitor directly across the Battery via a fuse so we know the voltage of the Battery at any time without going to the car if in bluetooth range.

[yossarian247]

Its worth pointing out that the Corolla owners manual contradicts CTEK's advice and states that when recharging the 12v Battery the car's earth terminal should be disconnected, then the charger connected direct to the Battery. That suggests that the point mentioned in the CTEK video about BMS doesn't apply here, or at least Toyota don't consider it to be an issue.

All I can say is that I've been charging the batteries on various Toyota hybrids for several years with a CTEK charger, have always connected it direct to the Battery with the earth clamp still connected and never had a problem with any of them. In fact in my Corolla I have wired the CTEK quick connector direct to the battery terminals.

[yossarian247]

15 hours ago, AndrueC said:

I'd be surprised if our hybrids have a BMS for the 12v system. Certainly not one as suggested in that video. The state of the 12v battery on our hybrids is unlikely to be taken into consideration by the ECU when balancing vehicle emissions.

I'd also suggest that the plethora of complaints from owners who have suffered a flat 12v battery make any kind of 12v BMS highly unlikely. 

Indeed the impression I have is that the 12v battery is left to fend for itself and largely ignored by the ECU (it almost seems to have been forgotten about by Toyota, lol). The idea that there is something in the car monitoring its health and trying to optimise its use seems unlikely.

Yes, on many modern vehicles when replacing the 12v Battery for any reason the ECU needs to be programmed with the capacity etc of the new Battery for the BMS to work correctly. This doesn't apply on Toyotas, which suggests either they don't have this type of Battery management system, or if they do it is 'plug & play'.

[Tommy X]

1 hour ago, yossarian247 said:

Its worth pointing out that the Corolla owners manual contradicts CTEK's advice and states that when recharging the 12v battery the car's earth terminal should be disconnected, then the charger connected direct to the battery. That suggests that the point mentioned in the CTEK video about BMS doesn't apply here, or at least Toyota don't consider it to be an issue.

 

Obviously if the negative terminal is disconnected as stated the BMS is bypassed, it would help if someone posted a photo of the Battery negative terminal of their Hybrid car, here's mine on my Honda Jazz Hybrid with what I assume is a BMS module attached 

 

[yossarian247]

This is the negative terminal on my 2.0 Corolla, which does look like some form of Battery management system.

[Tommy X]

Found this on a 2021 Corolla Hybrid, I assume it's a BMS unit, sorry not the best photo

  

[AisinW]

Corolla 2.0 and Auris has similar way to connect to charger. The easiest way is from the fuse box + terminal that is covered by plastic. The - is connected to any bare metal as usual. There is no difference between AGM and Wet Battery in term of charging. The AGM fully charge is a bit higher voltage, about 13.2 V meanwhile wet cell is 12.6. But anything above 12.6V is good.  CTEK5 has good management system as good as Lidl/Aldi 12£ charger. It is hot, susceptible to humidity, and the switch is plastic, be gentle with it and don't keep it in humid garage for storage. 

[Mr Billiards]

1 hour ago, AisinW said:

Corolla 2.0 and Auris has similar way to connect to charger. The easiest way is from the fuse box + terminal that is covered by plastic. The - is connected to any bare metal as usual. There is no difference between AGM and Wet battery in term of charging. The AGM fully charge is a bit higher voltage, about 13.2 V meanwhile wet cell is 12.6. But anything above 12.6V is good.  CTEK5 has good management system as good as Lidl/Aldi 12£ charger. It is hot, susceptible to humidity, and the switch is plastic, be gentle with it and don't keep it in humid garage for storage. 

Its not practical for me to charge the 12V Battery from the fuse box as my car will be on the drive while I'm away for two weeks (my garage is not wide enough to open the car door and exit the car)

As its a 2ltr with the Battery in the boot I need to leave the CTEK on,  located in the boot.

Following the posts above I'm totally confused as to how I should connect the CTEK to my Battery while I'm away.

[AisinW]

@Mr Billiards You can connect at the + and - terminal on the Battery. You can bolt the eyelet quick connect terminals that come with CTEK directly on the Battery. So you can just plug in and out anytime you need. I did the same with my Noco5 charger. I disconnect/unscrewed the eyelet from the clamps and bolt it directly to the Battery terminals + and -. Ctek has 2 quick connecg cables instead of 1 like in Noco5. 

[Mr Billiards]

46 minutes ago, AisinW said:

@Mr Billiards You can connect at the + and - terminal on the battery. You can bolt the eyelet quick connect terminals that come with CTEK directly on the battery. So you can just plug in and out anytime you need. I did the same with my Noco5 charger. I disconnect/unscrewed the eyelet from the clamps and bolt it directly to the battery terminals + and -. Ctek has 2 quick connecg cables instead of 1 like in Noco5. 

Thank you I will give it a try 👍

[Tommy X]

2 hours ago, Mr Billiards said:

Its not practical for me to charge the 12V battery from the fuse box as my car will be on the drive while I'm away for two weeks (my garage is not wide enough to open the car door and exit the car)

As its a 2ltr with the battery in the boot I need to leave the CTEK on,  located in the boot.

Following the posts above I'm totally confused as to how I should connect the CTEK to my battery while I'm away.

May I suggest before you go away fully charge your Battery, on return fully charge again, I have seen another CTEK video and the guy specifically states to connect the negative charger lead to an earth point on the car body, if you use this method at least you have bypassed the BMS      

[Derek.w]

On 11/11/2024 at 2:12 PM, yossarian247 said:

This is the negative terminal on my 2.0 Corolla, which does look like some form of battery management system.

Look like it handeling a lot of amps aftermarket BM monitors the voltage only as mentiond earlyer charge directly from Battery terminals without removing earth best practice toi connect charger then switch on it power.