tooold2race

According to an article in today's Wall Street Journal , most EV's have a conventional type 12 volt battery located somewhere in the vehicle that powers many of the accessories (ie: door locks, interior lighting, sound system, etc). The jest of the article is that it seems to be a weak part causing numerous failures due to programming issues that let the battery run out of juice prematurely.... stranding the users. Hyundai, GM and Rivian were singled out as having problems with their latest offerings. The article did say that the Tesla truck does not rely on a 12 volt battery to power its accessories since it uses a 48 volt power source.

Does anyone know if out EQS's have one of these 12 volt accessory batteries? If so where is it? The article suggests that the long term solution is to move to a 48 volt system but the 'accessory manufacturers' aren't there yet with components that operate on 48 volts.

Is this something that we should be concerned about???

streborx

This is hardly surprising. Automobiles have been built around 12 volt electrical systems for as long as I can remember. Converting the entire infrastructure to 48 volts -- everything from light bulbs and relays to audio systems -- is not likely to happen in my lifetime. If Tesla has no 12 volt battery, likely it has a down converter that derives 12 volts from its 48 volt supply for all its accessory electrical systems.

But 48 volt systems are hardly problem free. Many dealers are coping with mild hybrids, having to keep the 48 volt batteries float charged so that the batteries don't die before being driven off the lot.

Radman991

As far as I know all Mercedes electric cars have a 12 v battery. In my eqs 580 sedan it’s under the front hood. I had mine replaced under warranty after a year because it would not hold a charge.
Look under service in your Mercedes me app and it will tell you the status of the 12 v battery.

hlothery

If you search this forum, you will find multiple articles on the 12V battery.....it has been discussed at length. Your high voltage battery recharges it regularly, unless there is some malfunction. But, almost all EVs have one to manage the accessories and to start the software. Luckily, the EQS has had few problems, but many of us carry a small jump starter which has the capability of starting the car, should our 12V battery malfuntion (which all 12V batteries eventually do). I got mine from Amazon.....there are a million of them out there. Search the forum.

ScottC2

Are you talking about a trickle charger? Or is there really a good method/device for "jumping" the EQ's other than the old ICE Jumper cable method?
Edit: i.e. I'd be grateful if you'd share an Amazon link with an example. If I search the forum, there will likely be so many, I will not realize when I land on the exact item I should be looking for!

streborx

Not being an owner of an EV, PHEV, Hybrid or Mild Hybrid, I am familiar with them only to the extent of what I read about them from time to time. Mild hybrids concern me most -- many car buyers are unaware that the car they're buying has this feature (and I wonder if even the SA's know). My understanding is that they have conventional 12V starters, but revert to the 48 volt motor/generator when auto start/stop conditions prevail. A problem with the 48 volt system can leave your 12 volt battery depleted, which you can jump start, but once running you can't drive the car (not because the car is inoperable, but because it's programmed not to run without the 48 volt system being functional). And these 48 volt power units (which include an auxiliary heat pump to regulate its temperature) are pricey to replace and are often on back-order from Deutschland. Maybe some of this is false, but I'm not anxious to find out through personal experience. However, I'm interested in learning about the experiences of current owners, as I suspect we'll all be owners of this technology in a few years.

hlothery

Your concerns are unfounded. EV's have a high voltage battery, which runs the propulsion systems, and a 12V battery which runs the software systems (MBUX, in the case of the EQS) I know of no current EVs (other than the one mentioned) which have a 48V battery, but my wife's mild hybrid AMG GLE53 has one, which augments performance and provides starter functions for the ICE engine. It has functioned flawlessly for three years now. All the EV's we discuss on this forum have a high voltage battery which runs propulsion, and a 12V battery which runs the operating system. Although there were12V battery problems with several initially (Porsche/Audi had many, MB had a few), those have largely been solved through software updates. You really should research these forums (Porsche, Audi, MB, Tesla) prior to going bonkers here about a problem which has largely been solved. You need to improve your research. Search the forums!

hlothery

Not a trickle charger, a jump starter device. Any of the auto parts stores, Amazon, Walmart, Costco, or Sams sell Lithium ion jump starter devices, They are small, many fit in the glove box, charge up at home and hold a charge for many months. When you need them, they deliver enough charge to start an ICE, or to provide temporary power for an EV to get the software going and the high voltage battery working to power the vehicle. Have never used mine, but it is in the trunk. Search any of the web sites mentioned above, and you will find a plethora of lithium ion jump starter devices. Sorry, don';t know how to give you a link.
Edit: Mine is made by Michelin, purchased at Costco.

streborx

And you should include the BMW forums in your literary sojourns.

hlothery

Been there, done that. I LOVE my EQS.

streborx

And I love my G550 and X7. We're all fortunate having the choices and the freedom to choose.

streborx

https://mbworld.org/forums/gls-class...s-3-weeks.html
Sorry - I couldn't resist.

streborx

https://mbworld.org/forums/eqs/88496...eqs-580-a.html
Nobody ( as in N - O - B -O - D - Y) is discounting G-Wagens.

ScottC2

Thank you for the tip. I found plenty on line, now that I know what I'm looking for.
I will get one. Looks like its a great thing to carry in the trunk for a variety of reasons.

Question: Are MB EQ's "negative ground"? Or does one simply connect the clamps to their respective positive and negative posts?
EDIT: And another question: If I store this jump starter in the trunk of my EQE SUV, I want to be sure I can get to it if the 12v battery is dead. Do you know if the MB "flip-logo-handle" is completely manual and will allow me to open the hatch even if the 12v battery is dead?

streborx

These lithium battery jump starters need to be stored carefully -- don't just stuff one under the seat and forget about it. Temperature is the main consideration -- temps above 50C (120F), easily attained in southern climates, should be avoided. There's a lot of energy packed into a small dimension -- a product whose user's manual needs to be thoroughly reviewed.

hlothery

MBs have a positive and negative connection inside the hood, near the 12V battery on the right near the passenger side of the "firewall". . I know I can manually open the doors, then drop the back seat mechanically and get to mine in the trunk. The hood latch is mechanical, not electrical, on all MBs. I think I can get one connected if I need to. Have not had to......thank goodness. It will at least (I think) allow me to get it into neutral and onto a tow truck if I need to. Hope all this never happens. Just emergency planning brought on by all the nay-sayers who don't own EV's, but feel the need to troll on EV forums. I transfer mine to my wife's ICE vehicle if we decide to travel in that.

ScottC2

Thanks for the tip on the temperature aspect. It's something I hadn't thought about! Studied the manual of the one I just ordered and it speaks of the 50 degree threshold as an "operating temperature" limit. It goes on to say never expose it to anything above 80 C. So it reduces my concern about fire/explosion, at least due to high ambient temperatures. I don't believe temps in the well under the cargo area will ever exceed 80C / 176F, even on a sunny day.

ScottC2

Thank you for the additional info hlothery! I just ordered one of these:

streborx

Yes indeed -- "you need to improve your research"
https://mbworld.org/forums/s-class-w...lfunction.html

hlothery

Don't feed the troll.