Spinner

Hello -- Newcomer to all things Mercedes. Can I use the two jump start points to charge the battery without having to disconnect the battery itself? Sorry if this is an age old question that's been asked and answered a million times before. Thanks.

dennish

I have charged mine while still I the car. Didn't disconnect anything. No problem.

JimMBC300

NZ-Merc

Hi, My advise is buy a Ctek battery charger after using several other brands I found then best by a long shot and the extra long accessory power lead just makes life easy.
Just open the hood connect it up with out disconnecting the battery.

benzdude

I use my CTEK MUS 4.3 with the battery connected on my 2011 W204. it also comes with quick connect cables that you can leave attached to the battery.

Knightmare69

Just to note, oddly Ctek doesn't recommend using the AGM mode even though our cars use AGM batteries, they told me to use the regular mode.

benzdude

it's called "cold weather program" and is mostly for charging cold batteries in winter. The mode with the snowflake icon.

I use it all the time in winter, with no problems.

Knightmare69

If it works for you great, I'm just passing along what the manufacturer told me.

NZ-Merc

Just some info may be handy, I chose the Ctek MXS5 with the accessory 2.5 meter extension lead and also the cigarette lighter connector as well as the normal connectors supplied with the carger.
I have 4 cars with various difficulties of connection the charger and 3 different types of batteries in the cars.

My normal cheap non brand 7 stage “smart" battery charger was not fully charging the 2016 A180 so the stop start was not working correctly which the dealer identified as the battery was not fully charger even though the charger had got through the 7 stages of charging and indicated fully charged.

That is what led me to the Ctek brand after doing lots of research.

The extra extension cord works well for my 1987 BMW M3 I put the cord through the drivers window and plug it in to the cigarette lighter socket as it is live all the time, the battery in the boot is a PIA to access the terminals so the cigarette lighter is best for me option.

benzdude

You probably misunderstood what they said. CTEK would never say "we don't recommend using the features of our products"

Also, there is no "AGM MODE." You can see in that diagram both normal and cold weather modes charge AGM.

Knightmare69

Seems pretty clear they're saying NOT to use AGM mode, and my MX5.0 does have a AGM mode.

benzdude

OK, it says "AGM option" on MXS 5.0.

However, he is saying do not use AGM and RECOND options IF the battery is still connected to the car.

The CTEK MXS 5.0 voltages can go as high as 15.8v in your AGM and RECOND options, which is bad for electronics.(look at your voltage chart)

If you disconnect the battery (from the car) you should be free to use any mode you want on your AGM battery.

From the Mercedes manual:



Never, Never press recond option while the battery is still connected to the car.