parkwood

Living in lockdowned france. Our local shops are 4km away so the car is only going to get a short run every 5 or 6 days. There is no opportunity to top up the battery by taking the car on a longer run. Usually the battery will show as partially charged after a trip to our local village and we will then use the car later or on another day perhaps to go to the nearer bigger town and all is ok. Also I know the battery will slowly discharge whilst the car is just standing around as well.

I have dug around in the barns and found a very very old trickle charger probably for the 70's! And a newer electronic one i used for the tractor mower which does 6 and 12v. That had a winter setting but seemed to stop working so i replaced it but i hooked it up to the tractor and it seems the straight charging function works if the lights are to be believed. The replacement is hardwired in the barn and the leads will not reach the car and I prefer not to have to demount it.
i know the eclass is a somewhat complicated piece of kit but can i simply charge the starter battery in the same way as the tractor mower? I ask as i know mercedes sell their own electronic chargers suited to their cars. Just do not want to hook it up and upset the cars systems.
Dealer is closed down so cannot ring them for advice.
Thanks and to all my fellow europeans bon chance!

JTK44

Check your owner's manual (my manual it is page 364) and you will see that you can use any regular charger: Hook the positive up first, then the negative to the grounding plug.

I was away for 10 days skiing and when I returned on my Mercedes App the battery was indicated "not fully charged". I hooked up my battery charger and the next day everything was fine.

Hope this helps.

cetialpha5

MB tends to use AGM batteries which use a slightly different charging algorithm. If you were in the US, I'd just just get a cheap 8amp charger like this one:


I wouldn't leave the charger connected, just long enough to charge up the battery and disconnect it and then charge it up every couple of weeks. It's well known that when they go bad, they will fry your battery.

MikeO3

If you use a battery tender (aka maintainer, trickle charger) you don't have to worry about disconnecting or leaving connected for any length of time. MB sells basic maintainers or you could opt for the manufacturers (CTEK) own version which is a little more functional such as this one:
https://www.ctek.com/fr/products/veh...-0-test-charge

Jhedmb

I am using ctek mxs 5 on my GLE350d bought from amazon for $99 cad. This is the same brand Mercedes Benz is using, they just put their MB stamp on it . Works like a charm.

BobbyT

I have the Ctek too, wonderful piece of kit. With three cars (two MBs and my old Porsche) and now driving very little, I plan to charge them all in rotation at least once a month. Lesson learned: while the Porsche will take charging via the cigarette lighter port, the MBs will not take charging from the 12V/15amp power outlet. For them, one must use the terminals in the engine bay.

Long Islander

We've used our E400 wagon only twice this year and it's been unused for 4 weeks now. Nobody entered it or opened the hatch during that time. When I connected the battery maintainer last weekend, it charged up right away (the battery maintainer has a green light to tell you when the battery is fully charged), so you can easily go a month or more without worrying about your battery as long as the car is untouched. Good luck with everything.

robert c

I’ve have several Granite pulse maintainers and like everyone else in lockdown no car use. I have used the 25 watt Granite on the collection cars because it will detect the battery type as well as the CTEK. As long as you use a maintainer with multibattery capabilities and don’t use a trickle charger you should be fine with a AGM battery. If you do have a trickle charger just remember to remove it when battery reaches full charge

bellavance

Two Questions:

1- Recently, my 2018 E300 asked me to turn on the engine when pressing the start button. One day, it even delayed starting of Comand (GPS and radio) for about a half hour after starting engine. I complained to the Dealer who recharged the battery, saying everything was normal. I think Dealer is wrong, as I've also noticed that the engine no longer stops on red lights.

2- Does the car use its Main Battery for Start / Stop function?

Thanks.

ua549

The E300 has just one battery.

vinnybenz

Hi folks,
This topic has made me wonder. My past 3 MB's have always had an issue with the ECO not kicking in. The dealer resolved it by replacing the battery under warranty, one had the battery sensor replaced. Now I have a 2019 E450 wagon with only 15,000km's on it. I live in the Detroit Mi area and noticed that the ECO will not come in unless the outside temps are above 60F. I also hardly drive the car except for short in city trips for groceries etc.
Could it be that the cooler weather is not allowing the battery to fully charge to power the ECO mode? Now if I drive the car for longer times during the day trips, the ECO mode will kick in the 45F up temps.
Should I be using a trickling charger or is it that the car is designed to use ECO this way in cooler temps?
Thank you

JTK44

Just my $.02:

I do not think it has anything at all to do with the battery.

I too have an 2019 E450: First, and I am sure others will disagree I like the ECO start/stop function. Anything that saves gas and reduces pollution I am all for!

I have noticed that start/stop is somewhat random: I believe the reason for this is that for the start/stop to work the engine temperature must reach a certain level. That engine temperature level combined with the outside ambient temperature determines when the stop/start works.

The start/stop works in Vermont when I ski, even below zero and on Long Island in the summer when temps can be over 90. But the stop/start takes longer to activate the colder it is.

Also, but I do not think you are talking about this, if other auxiliary functions like AC are on, the start/stop may not work.

Hope this helps.

vinnybenz

HiJTK44
I guess you have about the same temps as I do and experience the same ECO kick in's as I. If the car is running long enough and the engine temps reach a certain point the the cold weather will not prevent the ECO starting, I suppose my trips are too short for the temp sensors to kick in the ECO, I assume of course
Thanks

whoover

There are lots of reasons the auto stop is suppressed. But in my case, the number one reason is battery charge. Since I'm not using the car a lot now, I keep the CTEK on it and when I do go out, eco start works MUCH more often than when the battery is just charged by the car, even with mostly highway driving. The car's charging system doesn't come close to topping off these AGM batteries.

vinnybenz

Well for the cost of those tricklers, maybe I'll give it a try, hopefully before the temps rise this spring. Had a couple if inches of snow today, melted quickly

cetialpha5

Just be careful with the trickle chargers. When they fail, they end up frying your battery. I would just have it fully charge the battery and leave it off. I think in the latest round of CAFE changes, they don't charge the battery enough so you can get better gas mileage. But when they do that, they end up killing the battery early because batteries that are drained more don't last as long as ones that are fully charged. My W211 still has the original AGM battery at 12+ years. My W212 had the battery replaced by the previous owner a couple years ago. The W212 batteries just don't seem to last as long, probably due to the charging algorithm.

whoover

Others have mentioned it, and I'll give it three thumbs up. This CTEK is the only charger I'd consider. It has an AGM-only mode, is temperature compensated and is very safe. It's the same OEM that makes the MB-branded chargers, but has updated technology. CTEK is definitely the industry leader.

ua549

Here are some, not all, conditions required for ECO start/stop to engage. There are others but I can't recall them ATM.
1. The combustion engine must have attained the necessary operating
parameters (e.g. the minimum coolant temperature).
2. The relevant conditions relating to the vehicle must be met (e.g. sufficient voltage in the on-board electrical system, the interior climate has been regulated following the key start, the accumulator for the air suspension or brake system is sufficiently full). And the vehicle must be stationary, of course.
3. The relevant conditions relating to the driver must be met: the transmission selector lever must be set to D or N; no movement of the accelerator or the steering wheel; the driver's foot must be on the brake or the HOLD function must be active; the doors must be closed, the driver's seat belt must be fastened and the bonnet must be closed.
4. The ECO start/stop must not have been switched off via the ECO button.
5.Relevant speeds must have been exceeded after starting with the ignition key or during maneuvering, for example.

JTK44

UA549:

Great post!

#3: In my BMW if you moved the steering wheel while in stop, the engine started. On my E450 if I am in hold, which I always use, with the engine off, moving the steering wheel does not start the engine.

madtrader

I haven’t tested this, but I have read on this board that window and roof status (open/closed) are part of the eco mode start/stop decision too.

ua549

Start/stop works for me with the windows and/or sunroof open.

madtrader

I didn’t mean to imply it would not function with the windows/sunroof open, just that it is an input into the decision tree. What I vaguely recall an example was that under the right conditions, cracking a window might let the start/stop shut off your engine when one of the interior sensors would have otherwise not allowed it (like actual temperature not being near the set temperature on the A/C).

ua549

Interior temperature versus HVAC setting is an input, window position is not.

whoover

You might be thinking of the door position sensor, not the window. If the door is cracked, the engine comes on so you don't forget to turn if off if you exit the car while it has ECO-stopped.
https://media.daimler.com/marsMediaS...ml?oid=9361921

madtrader

Maybe I’m mistaken on the window/sunroof status. I just know I’ve read it on here. It would be nice to have a full list of the inputs.

About the door sensor, I have been able to open the door with the eco stop and the engine not come back on. I do get a big warning on the dash, but the engine stays off. My usual occurrence of this is getting home and putting the garbage can in the garage. I’ll stop the car, the eco stop happens, I put it in park, and exit the vehicle. Engine remains stopped. I usually leave the door open too. I get back in and put it in drive. The engine doesn’t start until I take my foot off the brake with it in drive.