Originally Posted by toban

Now, I’m new at this like everyone else but I did talk to the head mechanic at the dealership and he confirmed when the car is running, the generator charges the 48V battery and the 12V AGM battery together. He said if you put a battery charger on the charging posts it will place a charge on the AGM through the converter and charge the 48v lithium lion battery too. I’m now trying to find out if a special charger is needed.
I hope this is right because It would be very disappointing to be spending this much on a problematic system.
I hope MB gets it right in January as this is when my car goes into production.
thanks for you comments and anything else people find out would be appreciated.
Toban

Originally Posted by toban

Now, I’m new at this like everyone else but I did talk to the head mechanic at the dealership and he confirmed when the car is running, the generator charges the 48V battery and the 12V AGM battery together. He said if you put a battery charger on the charging posts it will place a charge on the AGM through the converter and charge the 48v lithium lion battery too. I’m now trying to find out if a special charger is needed.
I hope this is right because It would be very disappointing to be spending this much on a problematic system.
I hope MB gets it right in January as this is when my car goes into production.
thanks for you comments and anything else people find out would be appreciated.

Toban

Originally Posted by Brer Rabbit

I believe (page 584 of the owner's manual) that the AGM battery charges the 48-volt lithium battery via the voltage converter. The charger you buy should be AGM battery compatible. CTEK makes them.

Originally Posted by whoover

The starter is 48V so if there is a problem with the 48V circuit the car can't start. If the 48V battery fails it won't take a charge so you're dead in the water. The concept of using another vehicle's (12V) battery to power the starter is not applicable, so jump-starting doesn't compute. And there's no provision for 48V-to-48V jump starting because, even if AAA had 48V available, it would be way too dangerous to both people and onboard electronics.

Originally Posted by Ron.s

As I recall this has been discussed before and a special charger was necessary. Seemed like it was more than just AGM compatible. But....if the 48 volt has an internal short or whatever keeps it from holding a charge then it might not be possible to charge it anyway. I did a search and couldn’t find the discussion that might have been about a year ago.

Originally Posted by Brer Rabbit

Yes, CTEK makes the MB charger. Back in Oct I emailed CTEK and got the following email when I asked about a charger for the GLE 450:Hello,
There are many charger options for you including the Mercedes-Benz branded charger that is manufactured by CTEK. This charger is available through your local Mercedes dealership.
If you are interested in a CTEK branded charger, our MXS 5.0 (40-206) is designed for lead-acid and AGM batteries up to 160Ah. If your vehicle battery meets this criteria the MXS 5.0 will also work well.
For more information on our MXS 5.0, please click on the link below:
https://smartercharger.com/collectio...s/ctek-mxs-5-0
Thank you,
I figured if I was going to buy a charger, I would get one that was AGM compatible.

Originally Posted by mikapen

Correct, there would not be a clear-cut way to jump start directly form a 48v battery to the onboard 48v battery.

But you can get enough charge by connecting a 12v battery to the GLE 12v battery posts, and allowing the GLE converter to bring up the 48v charge.
It may take some time, but jumping a dead 12v battery in a 12v car always takes quite a bit of time, while the dead battery gets enough charge to spin the starter - same situation with a dead 48v battery. Follow the normal jump start procedures, connect the negative lead to a ground point distant from the battery itself, and keep the charging car running.

M-B has already planned for these situations, by providing the 12v jump start connectors under the hood, and separating the ground point from the battery.

Originally Posted by Lucky 777

So if this battery fails, the car is a dead stick? I'm amazed MB doesn't have software in place to allow the car to still operate with the inline 6 alone.

Originally Posted by Ron.s

It’s just a bad batch of batteries & not an ongoing problem. This is just a very recent issue, the 48 V has been solid for the prior 18 months. I recently sold my GLE 450 after ordering a GLE 53 and completely agree with Mikapen. The fuel economy and silky smooth drive train/engine make it the best in class. If it wasn’t for the gauge showing the EQ Boost in action, you wouldn’t know it’s even there. You won’t regret buying a 450....
We have one individual continually running the Mercedes GLE down posting the same crap. His dealer wouldn’t repair an oil leak (on an older car) to his satisfaction so now he jumps at the chance to cheerlead against the brand. IMO, ignore his posts and look for facts.
Edit: There is a Mercedes me notice when the 12 volt gets low on charge but I don’t know if it’s also going to work on the 48V Lithium. Other Lithium batteries I’ve used in tools just die when discharged vs NMH that get too weak to function but still have a little power.

Originally Posted by Brer Rabbit

Gees!!! Not the goal at all. Where did you get that idea? I am talking about buying a charger for the 12V AGM battery. That will take care of the 48volt battery all else being fine.

Originally Posted by whoover

This is the CTEK charger that I use. It's newer technology than the one M-B brands and is cheaper. CTEK is the state of the art in AGM chargers. Again, you just need a good AGM charger as the 48V lithium battery is charged indirectly.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Originally Posted by Brer Rabbit

Yes, CTEK makes the MB charger. Back in Oct I emailed CTEK and got the following email when I asked about a charger for the GLE 450:Hello,
There are many charger options for you including the Mercedes-Benz branded charger that is manufactured by CTEK. This charger is available through your local Mercedes dealership.

If you are interested in a CTEK branded charger, our MXS 5.0 (40-206) is designed for lead-acid and AGM batteries up to 160Ah. If your vehicle battery meets this criteria the MXS 5.0 will also work well.

For more information on our MXS 5.0, please click on the link below:

https://smartercharger.com/collectio...s/ctek-mxs-5-0

Thank you,

I figured if I was going to buy a charger, I would get one that was AGM compatible.

Originally Posted by toban

Okay, we’re getting all kinds of different signals how you can charge this 48v battery.

Originally Posted by toban

Okay, we’re getting all kinds of different signals how you can charge this 48v battery. Many people are saying you can charge the battery through the converter from the posts under the hood through the converter. Others have said the converter only works one way from 48v to 12v and not the other way around.
so, this last poster is going to let the vehicle sit for 5 months with a battery charger hooked up to the posts and the thought wax it will keep the 48V battery charged also through the converter?
so, who’s right here I wonder? I wish MB would come out with an answer or explanation?
I’m really confused now what will work and not work.

Toban

Originally Posted by mikapen

The VW Group, BMW and FCA (including RAM trucks) all use 48v, some optional - but they are belt-driven. 48v is the future of ancillary power systems.

There is a Standard that 60V or above needs additional safety features, and 48V systems can charge at up to 52V, so the 48V batteries are the sweet spot for cost-effectiveness.
Right now, M-B is the only manufacturer using the inline starter-generator. It's the simplest and most efficient of the current (!) systems. And, as I understand, the 4:1 and 1:4 voltage conversion emit less electrical Noise that other voltages, needing less shielding.
Expect a widespread adoption of 48v systems in the near future, as fuel economy and clean air regs get tighter.

And the fuel savings are real. I have spent a month in a GLE450, two weeks in a GLE350, and own a GLC300 - the last two have the 2.0L four. Guess what - in normal driving, I get essentially the same mpg in all the above, perhaps a bit more with the GLE450. That's saying a lot, especially because I am somewhat tempted to enjoy the smooth acceleration of the straight six. I.e. bury my foot more, in the 450.
The added EQ Boost is real, and regenerative braking is smooth, probably saving brakes, and the elimination of drive belts free up significant power to the wheels.

I know that M-B had a setback, when Tesla bought M-B's main battery supplier and violated the development/supply contract that they had. The CEO of that company (can't remember its name right now) was fired when he wanted to honor the legal contract. This made me realize just how ruthless E. Musk is, and probably just how ruthless the future of electric cars and autonomous driving will become.

Originally Posted by quattrogmbh

do you have this documented somewhere or is it just opinion?

Originally Posted by WA3CUJ

One of the biggest drivers for a move to 48 volt systems is the weight savings. As the ever increasing amount of electrified technology went into vehicles the load on 12 volt systems grew exponentially, requiring more, and larger conductor size, copper wire. Moving to 48 volts reduces the amount of wire and the conductor size making those wiring harnesses smaller and easier to design and install. The reduced current also results in reduced heat.

Originally Posted by WA3CUJ

One of the biggest drivers for a move to 48 volt systems is the weight savings. As the ever increasing amount of electrified technology went into vehicles the load on 12 volt systems grew exponentially, requiring more, and larger conductor size, copper wire. Moving to 48 volts reduces the amount of wire and the conductor size making those wiring harnesses smaller and easier to design and install. The reduced current also results in reduced heat.

Originally Posted by GregW / Oregon

While it is true wiring weight is saved, I seriously doubt it offsets the weight of the extra battery. Of course there are many other advantages which have been cited - elimination of belts, a seamless start/stop system, ability to run accessories like AC while engine is off, fuel economy, etc.

Originally Posted by MikeFLA

I agree with the idea of a 48 volt system, no belts, efficiency, etc. However having been, well still going thru this 48 volt failure ordeal, I'm wondering about the reliability issue. The fact that this particular failure can render the car useless at anytime, anyplace, within seconds, which it have proven to be true, I would chose a belt if I could keep the car running at this point. If the AC goes out, or the hybrid system doesn't work, you could still drive the car to the repair shop. I'm thinking that Audi, and others who still employ a belt along with the implementation of a 48 volt system might have thought this out a little more thoroughly. My opinion.

Originally Posted by whoover

But with no way to jump-start a 48V starter (which all these systems use), you're not going anywhere. It would seem a safe and standard way to jump-start a 48V car is the missing technological piece.