Question about max. charging power/current

[Zwerius]

Hello,

I've got a question about the charging power of my i3 Rex (2014).
I don't have the fast charging possibility on my i3 Rex.
I usually charge the car by means of the home charger that was supplied with the car.
It draws max. 10 Amps at 230V, so 2.3 kW.
However when I connect my i3 to a public charger (not being a fast charger), it's charging faster than at home.
I thought the max. allowed charging power was something like 3.5 kW?
But I can't find this number anywhere.
Of course the i3 communicates with the public charger such that the max. allowable current is not exceeded.
That's fine of course.
But I'd like to change my charging system at home in such a way that I'm using my solar panels in an optimal way.
For example by means of a Zappi charger.
But to design the system I need to know the max. allowed charging power for the i3.
Anyone of you who has this info available?

 

[JohnKelly]

With a level 2 240 volt charger, the maximum is just under 32 amps.... 7.7 kw. You will need a dedicated 40 amp circuit. I have used the Clipper Creek 32 amp evse for two years now... works every time, and I share it with the public on plugshare.

 

[alohart]

I thought the max. allowed charging power was something like 3.5 kW?

This depends on whether an i3 includes option 4U8 FAST CHARGING AC. Without this option, the maximum charging power is ~3.7 kW. With this option, the maximum charging power is ~7.4 kW. All U.S. i3's have included this option. I don't know whether 2014 Dutch or E.U. i3's included this option.

 

[Zwerius]

As far as I know, I don't have any fast charging option.
So my max charging power will be around 3.7 kW then.
Thanks.

 

[JohnKelly]

Your car does not have the DC fast charging option. I would not assume that your level 2 charging is limited just because of that. Two different things. I bet you can charge at ~32 amps or ~7.7 kw, if you are seeing faster charging rates while charging away from home. At 24 amps and the early battery, you should be able to gain about 30% per hour or 1% every two minutes... at 32 amps you should do even better. Be aware that as you get above about 90% the charge rate does slow down a lot.

 

[jadnashuanh]

TO keep the selling price down, lots of markets made the fast charging module optional. This is not to be confused with the DC charging. There are two modules in the USA that maximize the charging to 7.4Kw. Others will only have half of that.

There are a few markets that support 3-phase charging, and those can handle even more power.

 

[Zwerius]

With the help from a German i3 forum I found out, that the item on my invoice "Sterkere stroomvoorziening" (code 570), means that I have the possibility to charge with 7.36 kW.
So my question is answered.
Thanks everyone for helping.

 

[AndrewDebbie]

TO keep the selling price down, lots of markets made the fast charging module optional. This is not to be confused with the DC charging. There are two modules in the USA that maximize the charging to 7.4Kw. Others will only have half of that.

There are a few markets that support 3-phase charging, and those can handle even more power.

The way I understand it...

There are one, two or three 16Amp chargers rated to about 3.6kW each.

In some markets, only one charger is standard. Others get more.

4U8 AC charging Plus
4U6 AC charging Professional



If you don't have either option, the car has a single 3.6kW charger. That charger is part of the EME (Electric Motor). BMW reuse part of the motor to form a charger.

4U8 adds a KLE module and the car has two chargers. One KLE and one inside the EME. This will charge at ~7kW.

4U6 includes a 3-phase KLE. There are two 16Amp chargers in the KLE and the third is in the EME. On a 3-ϕ charge post, one phase is connected to each charger and the car charges at 11kW. On a 32Amp single-phase post, two of the chargers connect in parallel and the car charges at ~7kW.

 

[AndrewDebbie]

This is the wiring diagram for an i3 Rex with no optional charging. X578 is the charging connector on the car. The dark orange lines are the single phase AC connecting to the single charger inside the EME. E196 is the traction battery. REME is the range extender.

 

[AndrewDebbie]

This is the wiring diagram for an i3 Rex with 4U8. There is a 16A single phase KLE added to the basic charge. AC power from the charge connector goes to both the KLE and the EME. The KLE output connects in where the Rex used to go and the Rex output now plugs into the KLE.

 

[AndrewDebbie]

This is the wiring for an i3 Rex with DC rapid charge prep and 4U6. There is 3-ϕ AC input to the KLE as well as a DC connection.

2 phases of the input connect to charger modules at the top of the KLE block. A there is a switch to connect both chargers together for single phase 7kW operation.

 

[Zwerius]

You may be right about this. So this means then, that I've got the wrong information on the German i3 forum.
But then, what does the item on my invoice "Sterkere stroomvoorziening" (code 570) mean ??

 

[AndrewDebbie]

I think S570 means your car has the larger 12V battery. This is a guess. I'm doing some searching now. BMW use two sizes but both are small. There are 20Ah and 40Ah batteries.


What year is your i3?

Have you tried using a VIN decoder? Here what I get back from mdecoder.com for my 2018 i3s Rex.


4U6 is 11kW 3-phase AC charging.
4U7 is DC CCS charging.

My car also has 570 . I think all UK/EU cars have this as a 100% option.

 

[AndrewDebbie]

S570 might also mean our cars have a higher capacity DC-DC converter for the 12V system. It might get paired up with higher drain 12V systems. (Rex or heated seats or cold climates...)

Still searching.

 

[Zwerius]

My i3Rex is from 2014. I've tried the VIN-decoder, but in the specs that I'm getting there's no code 570 mentioned.....

 

[AndrewDebbie]

Maybe your car doesn't have it. ??

Do you have heated seats?



In 2014, the charging options were 4U7 and 4U8

 

[Zwerius]

I do have heated seats