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electricvirgin

Well-known member
Joined
Apr 3, 2014
Messages
90
Location
i3 Rex UK
I am having my Home Charger (EVSE) installed later this week (i am in the UK) and need some advice.

I have a solar panel system rated at 3.7kw and am having the more powerful (7kw) of the government funded (mostly) chargers.

I was thinking of having a standard 13amp socket nearby to the main EVSE to enable the car to be charged from the solar panels when the sun is out (it does happen sometimes!) as the EVSE would need more power than the array provides. The power from the array is sent to the grid if i dont use it, and i would prefer to try and utilise it if i can!

My question is can the car or EVSE be set to draw a lesser amount (over a longer period of course!) to try and match the output form the panels to the car? I thought i read this was possible via in car settings or perhaps via the app?
If so this might mean the 13amp socket is not needed.

I would prefer to go with the higher power charger for those times when a quicker charge is needed.

My car wont arrive until the end of august by the way.
 
I have the same situation. I tried to use Live Online Help to ask the actual charge rate for each setting but if I remember correctly, the first answer was by rote and inappropriate; after pursuing it the agent agreed to refer it to BMW i Tech Support, that was weeks ago and I've had no reply, so have given up expecting one.

The online manual only seems to make one reference to this, where it says (c p156) that the Low setting must be used when charging from a domestic socket. I'm assuming it will also be possible to use the low setting to limit the rate of charge when connected to the 7kW wallbox that I have had installed.
 
There were some figures posted earlier on this forum if I remember correctly. Try searching. I can measure mine, but I have the charger set to 15A rather than 30 so it may not be relevant.
 
There are only two settings to choose from.

http://www.mybmwi3.com/forum/viewtopic.php?f=11&t=1078
 
looking at another blog in relation to the question asked about optimum speed for REx on a long trip I've come across something relevant to this thread, which gives some info regarding charge rates but also refers to three charge rate options rather than two. I wonder if this is a difference between the UK and Sweden?

http://bmwi3owner.com/2014/02/charger/
 
There are two settings for the 'fast' ac charger Maximum and Reduced - I measure the latter to be roughly 15A (but my charge point is 15A anyway).

The supplied 'standard' (13A socket in the Uk) has three:

Maximum 10A
Reduced: 7-8A
Low: 5-6A.

I can get more accurate figures if you wish - just have to dig out my Fluke clamp.
 
At least with the protocol used in the USA, the EVSE indicates how much power it can supply, and then the vehicle can be adjusted via the menus to restrict how much it uses. What could work, and I think there are some EVSE that have this feature, is for them to vary how much power they can provide via their signaling line, then, regardless of what the vehicle might want, it would not be able to draw more than that from the EVSE. On some, there are DIP switches internally to adjust that signal level, but I think I've read about some that also have a front panel menu that can do it as well. Not sure if any sold in the UK have this feature.
 
Same protocol in the UK. Some charge points can vary the available current with a variable resistor. Mine does this to restrict the 32A basic unit to 15A.
 
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