Phil_T

Please can people confirm the correct method for trickle charging, I want to make sure the car starts after putting the car away for storage and just bought a ctek mxs 5 but the manual for the battery charger, car manual and people online all have conflicting info.

The manual for the car says for charging use the negative under the bonnet and earth to the inner wing and do not charge direct to battery.

A user on another forum said charging from under bonnet is only for the starter and will not charge properly as the main battery has constant drain for all car electronics and to direct connect to battery in boot, but I have looked online and some say dont direct connect!

Ctek manual shows conneting direct to battery and gives two different methods.

Mort

I don't know which way is technically correct but I also attach my CTEK directly to the battery. No harm that I know of so far and I have been doing it that way since 2010.

pbaylog

I run mine to the underhood connections and maintain a full charge...more convenient than running to the trunk

quaalude

+1 here. I use a Schumacher battery maintainer.

bhamg

First, to be technically correct your Ctek "float" rather than "trickle" charges, two very different things. I generally keep two cars on float chargers all the time. But to answer your question, utilizing the under-hood connectors is the way to go, although I think the best thing to do is to take 10 mins to hardwire your charger-supplied connector of choice to the adjoining terminal block under the plastic cover.

otakki

Make sure you use a good ground for the negative, if you cannot hook up directly to the battery's negative terminal. That is because contrary to popular belief, electrons actually go from the negative to the positive.

realjones88

The giant bolt in the engine bay that is there for specifically this purpose would be a good starting point.

I have always used the engine bay hookups, no problems.

Alex.currie44

I bought a Battery Tender Jr when I got my first gen SLK which sat for several months while I was away.
It came with a connector that you bolt under the clamp bolts on the battery. When you want to use it you just plug the connector to the charger. When you want to go just unplug it. No fusing with cable clamps etc. It shuts itself off automatically when the battery is fully charged.Cost me $25. Best car part I ever bought. Simple to use and cheap.

Phil_T

Thanks guys, appreciate all the help.

roadkillrob

I also use a battery tender with the permanent installed cable to the battery, just pop the trunk, plug in the battery tender to the cable and close the trunk. Cable hides under the floor when not in use and the back of my car is better/closer to the wall plug.

Also, I always put a sign on my steering wheel to say it is plugged in so I don't (or anyone else) get in and drive with it attached!

rorywquin

My manual says to use the jump start points under the bonnet. I use a CTEK charger which, MB, & Porsche et al rebrand. Ctek provide kits for permanent connections with a quick release connector If you ant to go down that route.

Phil_T

When charging through the hood do you guys close the hood and feed the wire up through the windscreen to be able to close the hood? I am guessing the charger needs somewhere to rest too because it will get hot?

pbaylog

My charger hangs from an overhead outlet, then the cables run under the hood on the front passenger side. I am able to latch the hood but not fully close it. This doesn't seem to pinch the cables or upset the mounts. I am also able to place my car cover on from there, but I do loosen up that front corner for access. The charger itself ends up resting on my car cover. You may want to place a towel there, or something to keep it from scratching the paint.

Phil_T

Right so I am wanting to install to comfort indicator to hook up for permanent easy charging but mine looks different under the hood being a UK car. Any ideas with two parts I should be connecting to?

http://img.photobucket.com/albums/v4...psv5s7lf5k.jpg

http://img.photobucket.com/albums/v4...ps1b0yk66q.jpg

Alex.currie44

I cannot figure out what I am looking at but I am confused. My battery tender jr came with a wire with a loop on the two wires at the same end. The one oo the red wire went under the clamp nut on the positive terminal of the battery and the other under the clamp nut of the negative,. A 5 minute fiddle with a 9-10 mm wrench. The other end is a combo male/female small molded plug so you cannot hook it up incorrectly about 1/2 inche across, 1/4 thick and maybe 1 in long. The charger had the same plug. When I want to use it I just plug the two together and then plug the charger in. When the battery is charged it shuts off automatically. All for $25 CDN. Simple.

Phil_T

Alex.currie44

Make it easier on yourself. Go into the trunk (boot) and connect it directly to the battery.

Phil_T

bhamg

Phil - That is totally different (obviously) from what I have. I wouldn't mess around with that, TBH

Phil_T

rorywquin

For my car, the manual clearly states that the jump start terminals should be used......

Phil_T

Alex.currie44

What ever suits your fancies gents. We are not discussing jump starting here. We are discussing trickle charging.
I have had 11 of these cars and the last 6 have been left for 2-4 months at a time so I use trickle charging.
Some had batteries under the hood or in the trunk. Some have had seperate batteries behind the dash that just start the car so using the under hood terminals is the only option. As far as I know these W204s of ours have only the main battery in the trunk.
All the under hood terminals are an extension of the +ve from the battery via a cable from the trunk in the harness and the brass ground is just that - a ground attached to the frame as is the -ve of the battery itself.
If you have to jump start it of course it is easier to just open the hood and MB is not unknown to make things difficult but you do not have to attach a trickle charger at those points too.
Do as you wish. The OP seemed confused and I was just suggesting it can sometimes be easier going to the source.

Mort

Phil in the first pic you put your positive connection, from the charger, on the blade that sticks up in the middle of the black plastic terminal block. All three of those bolts you see in your top picture are positive connections.

In the second pic you put the negative terminal,from your charger, on the copper colored post to very right top side of the strut tower.

rorywquin

Correct we are not discussing jump starting......and no one was criticising your recommendation......my user manual states that the jump start points must be used for charging ........I'll stick to the manual.....however others may prefer your recommendation