Hi, I've made a fused lead up for my ctek charger (MXS7) to use 13 pin trailer socket and it works great.

I've checked voltage at battery and with the ctek showing battery fully charged the voltage is 13.3v. Is it safe to leave charger on with this voltage input to battery or will it cause damage? I have read anecdotal reports that ctek chargers can do this.

Should I just connect charger when battery voltage drops?

TIA Andy
Freelander2 HSE (59 Plate, MY10 spec)

I just looked up your model charger quickly, it's sold as a smart charger so I am going to say "yes"..........I have a CTEK MUS 4.3 Polar and I leave mine connected with an AGM battery without issue. I have my Polar connected to a programmable timer also.

I don't have that problem with the solar panel as the controller sorts it all out.

Further, I do have a mains battery charger that 'Charges' and 'Maintains' when fully charged, which I tend to use in the winter months.

Finally got a 13 pin plug via ebay (the first one never arrived) and made up a lead. I have to report that it works very well - left on charge overnight and showing full charge this morning. I'm very pleased with this solution. Ian.
2013 LR2 SD4 XS
1982 Moto Guzzi V50
1952 Norton ES2

I am slightly confused, seems to happen a lot these days!! My handbook TD4e 2010, says " The battery must be disconected and removed from the vehicle before charging. Failure to do so could result in damage to the vehicle's electrical system." This seems to mean that a charger should NOT be connected to the vehicle without disconecting the battery. Is this because mines an AGM?

I have just put my FL2 on charge without disconnecting the battery.

Have done this before, also without any issues.

That statement in the handbook is generic for all models about disconnecting the battery.


Just make sure you connect the cables to the right terminals. Red to + and black to -

If you are using a CTEK charger it is unlikely to cause any problems.

My handbook says the same but advice from here suggests that it's unnecessary. I had previously connected the charger to the battery direct onto the posts with no problems. Ian.
2013 LR2 SD4 XS
1982 Moto Guzzi V50
1952 Norton ES2

It's a Cover Your Ass warning. Things could go wrong in a worst case scenario: You connect the leads in reverse damaging or bricking your modules (charger may have reverse polarity protection), a spanner falls and touches both posts each covered in lithium grease and a dragon breathes fire , the charger malfunctions and overloads the voltage and amperage, etc..

If your charger leads have an inline fuse, you technically should have one less thing to worry about.