Long term storing EQS
 

I am about to go on a trip for 4 months and can't find info on proper storage. Specifically concerned about the 12v battery(s). Most EV's require a trickle charger/maintainer as it is problematic if the 12v dies. There does not appear to be any way of maintaining the charge on the 12v. The manual is no help.

Found this at an Autp-Volt site:Mercedes-Benz (and smart electric/EQ models)

All electric and plug-in hybrid (EQ) models – When a customer activates their “Mercedes me” account, they can receive SMS or Mercedes me app alerts if either the 12V battery or high-voltage battery becomes critically low – prompting them to recharge the high-voltage battery.
Similar to a 12V battery, it is normal for a high voltage battery to lose a little charge when the vehicle is stationary for prolonged periods – but this depends on a variety of factors. Therefore, Mercedes-Benz generally doesn’t recommend leaving, for example, an EQC stationary with a low battery and unplugged for prolonged periods – but customers can get alerts sent via Mercedes me informing them if the battery becomes critically low.
When an EQC or EQ Power vehicle is put on charge, it also internally supports and charges the 12V battery – so a separate charger would not be required.
It is safe to leave an EQC and our EQ Power plug-in hybrid vehicles plugged in for “long periods” if desired.
On request customers can receive a push notification when the charging process starts and ends.
All new EQCs and Mercedes-Benz EQ Power vehicles come with complimentary Roadside Assistance within the first three years of ownership and every year thereafter when the vehicle is serviced within the Mercedes-Benz network. This includes assistance in the event of a flat battery.
Mercedes-Benz customers can find out specific battery and charging information within the respective model owner’s manuals.

The obvious? is,”Can you get someone to help whilst you’re gone.

I will be away for two months, and plan to follow the suggestion of leaving my 450 at 50% charge.

I will monitor my charge level regularly - if it starts dropping to a point of concern, I will have a friend hook it to my charger.

If you’re not able to do that, I’d ask your dealer to get some suggestions for you.

If you can leave it plugged in to a L1 or L2 charger while you are gone that is all that's needed. Set the max charge to 50% and you are golden.

You should not leave it plugged. Charge it to 50 and lock the car and thats it. I stored my EQS for 2 weeks. When I returned the SOC was exactly the same as I left it, 50.

I’ll swing by and take it for a quick spin once a week, I wont even charge you for it! :rolf:

You are incorrect... and 2 weeks is not the same as 4 months. I also left mine at the airport for 2 weeks without issue. I wouldnt do the same for 4 months. I would do as Mercedes recommends and leave it plugged in if I can.

But Mercedes does not recommend to leave the car "plugged in".

I believe c4000matic means the high voltage battery would survive well from 2 months parking if the battery did not lose any significant charge during two weeks. Starting from 50% would leave more than a safe amount of charge.

The 12V battery is the concern if the car is parked for 2 months. Honestly I'm not sure about the EQS if it only charges the 12 V battery when ignition is on ("engine on") or also when the high voltage battery AC charger is connected. The manual seemed to state that drive mode or DC charging would do it but DC or AC charging should not be different for the 12 V battery. In any case, leaving the car plugged in is against the Mercedes recommendation.

So, no really definitive reliable suggestion fits everyone’s situation - yet.

Why don’t you just hook it up to a trickle charger?

Is it possible to access the small battery?I thought it is under the hood?

Are there smart plugs that can be installed which allows you to cut electricity or let electricity flow from the control of an app on your phone? That way, I guess just plug the charger end to the vehicle and then the charging device to the smart plug and then monitor the EQS' battery via Mercedes Me aboard and turn on the smart plug when needed aboard?

It is under the hood but to attach a trickle charger you can just pop open the hood and stick one on just like any other vehicle. The OM doesn’t really give direction for someone who can’t check on their car every 6 weeks

I thought ChargePoint or JuiceBox allows you to schedule charging session.

They do. My Juice Box App gives me lots of choices. Like, turning off "smart charging", "charge now", "no charge". That is why I suggested leaving the car plugged in and managing the charging with the Mercedes Me App and charger App.

“…just pop open the hood…”

Why am I thinking MB strongly discourages this?

Maybe the 400 volts running around in there? However, the same terminals to jump start that 12V battery are there, just like in any other MB car. Would be fairly easy to hook up a trickle charger for that.

Good point - there are such smart circuit breakers, you can find on Amazon and it´s very easy to remotely turn on/off the whole L2 circuit or create a schedule

Don't forget to inflate your tires to max PSI to reduce flat spotting.

When i went out of the country for 2 months i hooked it up my Ctek 7002 to the 12V battery. Everything was normal when i got back. Hi voltage battery lost about 2-3%. This is what under the hood of the EQS SUV look like, i'm sure it the same for the sedan. Under this black cover is a red sliding cover for the +12V battery terminal. see picture.
https://cimg1.ibsrv.net/gimg/www.mbw...c1150ffb0e.jpg

Everthing done correctly. Note, for a 2 month storage it was probably safe even without the trickle charger, unless stored in the bitter cold.

I had a personnal experience, my EQS sedan was stored for 5 months last winter being in Europe non stop all that time. What I think is the High Voltage battery in no concern. If left at 50-55% SOC it did lost about 3% in 5 months. NO BIG DEAL. However the 12Volt battery is more of a concern. There is always some minor current draw from it all the time. Having the Mercedes Me app I was able to monitor the condition of the 12 Volt Battery but no means of recharging it from the distance. My point is as follow. I did open the bonnet and used the post available to install an intelligent 12 Volt battery charger the night before putting it in storage. The battery then received a full charge and was barely able to withstand the 5 months of slowly discharge. An other very important trick is that as soon as you can get access to the car, plug the car for the slowest recharge you can provide. Reason is while the High Voltage Battery is charging, so is the 12 Volt Battery. And if you can extend the HVB charging process for 12 hrs or more, you can be pretty sure your 12V battery will have had all the time it needs to fully recover. Contrary if you use a fast DC charger for 30 min. or so the 12V. battery will not have received much. And then using the car all the energy that vehicle is using will not permit proper charging conditions for your depleted 12V battery. This is looking for problems.

Finally if you have the opportunity to get someone plug your HVB once a month for a very slow charge, this will replenish the 12 V. battery as well.

Interesting. So someone in the US could simply plug their vehicle into a 120v level one charger with a simple smart wifi plug and have the wifi plug on a schedule to turn on the charger just a few hours each week.

Yes this is what I do. I leave the car plugged in to a 240V L2 charger, and set it to max charge of 50%. This will lead to the 12v battery also being maintained. Tjhedya was correct above. You can have car plugged in at 50% charge instead of having a trickle charger on the 12V. This is what MB roadside assistance told me when my battery went flat during the PPF and tint installation.