El Cid

Battery replaced in Dec. by dealership. Dead this morning and Roadside Assistance came and jumped it. Didn't have battery so said I could take it in to dealership to get it replaced. Told him about right side parking lights (below) and he said might be a control module.
My concern is why it went dead. About once every 2-3 months the right side parking lights come on during the night. I turn them off the next morning. Dealership ran an XENTRY(?) test in Nov. 2016 for this and came back NPF.
Any suggestions.

KEY08

LALALAND

Look like you need a battery charger if they can't find any problem. I got a CTEK Mus 4.3 charger that I use on both of my cars about every 4-5 months since I don't drive over 8 k combined annually. They make charger for all MB, BMW, and etc manufacturer. Of course it will cost more if you buy the automaker's brand. In you case, might need to charge every month or two.

El Cid

Always lock car, even in daytime.

El Cid

thanks. Been trying to avoid that. How do you hook one up and leave the hood down? Actually I drive my car at least every other day, but sometimes for trips less than five miles or so.

Mud

Ctek is a great maintainer, I happen to use Schumacher 1.5a Speed Charger (maintainer) on my restored cars that sit a lot. It comes with 2 ways to connect to battery - a set of clamps with connector and a set of ring terminals with connector. The maintainer has a corresponding connector that attaches to either set. If it's more of a temporary connection, use the clamps. If more permanent use the ring terminals bolted to the battery terminals and route the connector plug to somewhere convenient to get to. I lengthened the leads to do this. The connector can be somewhere unobtrusive, you then just attach the maintainer to this connector without having to open hood etc. Been doing this setup for many years, even on riding mower.
But I agree with your overall perspective that there is something not right about such frequent battery issues. The maintainer addresses symptom only as you know.

LALALAND

You can mount the eyelet(comfort) connections directly into battery terminal. For charging pull the connection back toward the back of the hood toward windshield and out so that you can close the hood and make the connection with the Ctek (or what ever you decide to buy) to charge. I put a empty box (about 3-4 inches tall) above the right side air intake since it's not use by a E350 then put the hood on top of the box. This leave about 4-6 inch gap in front of the car to run the cable to the charger on the ground.

El Cid

Googled battery chargers and maintainers and the Schumacher. Way too many choices out there. What about prices for a simple, but effective one. That may help me narrow it down.
Seems Cen-Tech Maintainer and Float Charger at Harbor Freight is $20.

How do you keep the charger charged?

Also have a new riding mower with 12 volt battery and a pick-up I drive far less than the M-B. Can I use a device to recharge their batteries if they die or get weak?
Hate to sound dumb, but I am when it comes to this stuff.

Mud

I'll repeat to clarify, not to push that anyone has to buy the same as I have.

I've used the Schumacher SEM-1562A-CA 1.5a maintainer for several years now. In fact I have 4 of them, used for vehicles and riding mower. Yes you can use it for both. All have been very dependable. I had an issue some years ago with HF maintainer - it did not recognize full charge on the battery and kept applying voltage. I like the Schumacher as they cycle maintenance voltage to the battery without any problems. No overheating.

I also have 2 battery chargers/starters but I use these mainly just to jump start vehicles with low or dead battery. Not for constant connection as the amperage will be too high for long term use.

The maintainer is plugged into a 110v wall outlet and provides 12v dc power at low amperage to the battery. This will be similar to whichever brand you decide to get.

DFWdude

Not sure why this has devolved into a battery charger/maintainer thread. These cars should not require any charger.

Mud

El Cid

Thanks to all
NEW story from the dealership. Rather than drive one hour to show up at dealership on a Monday AM, I emailed the service manager. He replied that the battery died because the right side parking lights were coming on all the time. Called him and explained that that absolutely was not the case, but he said that they were coming on enough to drain the battery. Once every couple of months and only for a few hours?
My Nov 2009 build date model has the older switch that has both an O for off and A for automatic. Separate switch for parking lights. You can leave it on O with the DRL's enabled and the headlights come on automatically. You can do the same thing with A, but that also causes the "entry" lights to come on when you use fob to open car. As car is in a dark garage, I used the O rather than A so the "welcome" lights would not come on every time I opened the car doors.
SA said leaving it in O causes the parking lights to come on automatically? Why would it only be the right side ones?
He also said that letting it idle for two hours would not charge the battery as the alternator only works when car is moving. The Roadside Assistance guy had told me to let it idle for two hours - which I did. SA said driving it 20 miles will fully recharge the battery! Have not tried to start it as had no where to go and was going to wait for appointment with dealership.
SA said no reason to bring it in and nothing wrong with the battery or the car.
Any thoughts of the above?

DFWdude

Writing this to offer a change of opinion. While the Pandemic situation persists, I've purchsed a battery charger and connect it whenever needed.

I have found that low battery is indicated when the Comand system -- which I choose to leave on by default -- does not turn on when the car is started. I will soon buy a maintatiner, too.

El Cid

Thanks for the update. Not sure what you mean by leaving "Command on by default." Believe your first opinion was correct in that these cars should not need a charging or a maintainer as they do. Especially considering the cost of MB batteries. Have owned dozens of cars and never needed these before. Batteries always lasted four to six years and these were regular batteries.

DFWdude

I always have some source working in Comand while driving, most usually the MEDIA player. I leave it playing when I park and turn off the engine.

Normally, when you later return to the car and start the engine, Comand resumes operation automatically... if there is enough battery charge. If the screen is dark instead, it tells me that a battery top-off is indicated. This is a more reliable "tell" than waiting for ECO Stop/Start to stop working.

My E350 shares garage space with my wife's 2014 Sonata (with original battery). I swear the Sonata laughs at me when I connect the charger to the Mercedes (2-years newer on its third battery). BTW, my C320 is 20 years old next May, and it is using only it's third battery

El Cid

Confusing to me, but a lot of things are. I assume by Command you mean the Audio system? Mine is always on with either radio, Music Register or CD player operating. Goes off when I turn the car off and back on when I turn the car on.
My other vehicles are a 2014 Nissan Rogue (great vehicle) and 2011 Toyota Tacoma. Rogue still on original battery and had it checked last month - OK. Replaced the Tacoma's at 6 years since I seldom drive it.

LILBENZ230

How long are you guys letting the W212s sit? Mine doesn't get driven that often these days. In November while I had COVID, it sat for basically the entire month. Never had any issue.

DFWdude

YES, we're discussing the Audio system (and all other Comand functions). It operates from the "last used" principle, just as I described, and you reiterated. Set to on, when you start the car and the system does NOT power-up, it tells you the battery has less charge than needed to restart the audio system.

Mud

Suggest checking for a parasitic drain on the battery. With the car "asleep" there should be very very low millivolt draw when a multimeter is connected between battery neg terminal and neg cable. I believe 20mv is target , can sometimes be a bit more or less. Lots of YouTube to fully explain.

When I say "asleep" that means the car has to be left undisturbed for a period of time, doors closed , etc so all modules shut down. The small mv draw is typically for ECU memory, clock, immobilizer.

If there is a substantial draw found, individual circuits at the front and rear SAM (fuseblocks) can be then checked to isolate the circuit with the draw. PowerPoint.com has a good chart correlating mv to amps but you can also use an ammeter for determing draw.

Might be that there's a module that stays on - it will test fine on a scan because it's functional. But if it never shuts off it will pull the battery down.

DFWdude

I've accumulated just 1300 miles since Feb, so the car sits long periods. I try to start it at least once every two weeks, but do alternate between the MB and the Sonata to maintain the battery in both. And when there is rain, I use the Sonata first, just to keep the MB unsullied.

In addition, I don't habitually lock the E350, as there is always some need to open a door when I don't have the key fob on me. I've read here that unlocked can cause more battery drain than locked. I know there is always some battery drain that accumulates over time.

Bottom line... the car will always start and operate as normal. And, it can sit for a couple months without issue. The difference is that the Comand Audio System (radio, media, phone, nav, etc) will indicate battery state if it doesn't turn on automatically when the engine is started.

I can't imagine many folks purposely turning off the Comand System before parking and exiting the car. Soooo, it should be on when engine stops, and return to on when engine is restarted. If you haven't noticed this yet, you might check next time...

El Cid

Probably depends on the age of the battery. Mine is three years old this month. Last Nov. it wouldn't start, so called dealer and he sent Roadside Assistance guy over to check it out. He would have replaced it but did not have one on truck as he had already replaced two that morning. So he jumped and said to let it run for two hours. I did, but also called service manager to complain and he said letting it run does nothing - car has to be in motion to charge the battery. Said to drive it about 20-30 minutes. Battery was still under the two year M-B warranty and they checked it in Dec. and said it was OK.
So, at least once every two weeks I go on a 20-30 minute drive through the countryside if I have not driven the car lately.
Recently Consumer Reports had a brief statement that due to Covid-19 people need to drive their cars once per week for 20 minutes or more (if I remember correctly).
In past 12 months, I have only put about 1,000 miles on my car. So far, it starts when it should. Temp was 29 yesterday, but naturally warmer in the garage when I started it at 7:30 AM.
Interestingly I am taking car in on Dec. 31 for annual service.

LILBENZ230

Okay if you're at 1,000 miles in the past 12 months then you are driving way less than me. My car is at 12,000 in the past 12 months.

Clears that up.

DFWdude

I might head to HF later today to buy this maintainer... https://www.harborfreight.com/12v-de...MaAvRGEALw_wcB

This unit has quick disconnects with waterproof caps (for two cars if used with imagination) and includes cross polarity protection that the $10 HF doesn't have. I plan to install the quick connect to the back edge of the hood, ahead of the starboard wiper.

I can see spending $25 or so for this, but I'm not paying up to $100 that places want for the ctek.

cetialpha5

I like this 8 amp charger, better than a .75 amp maintainer. Prices of everything seem to be up lately, used to be around $20 a few years ago. Used it to charge up a battery a couple times. Too many horror stories out there about cheap maintainers that end up frying the battery when they fail.

DFWdude

Among the 125+ versions of Schumacher products out there (way too many models with too many features to sort through -- with prices all over the map), this is the most economically priced, and says it supports AGM batteries. I may get this one. Then again, I may not...