Granny charging (by Renault this time)

Renault has been selling the official Zoe granny charger for a while. The official name is AFAIK the “Flexi charger”. It retails for a bit over 700 euro’s. Charging current is fixed to 10 amps. Slovenian forum member “pirpy” dissected it (partly) and noticed there is a control wire to the Schuko plug to change the maximum power setting to 13 amps. It is done by using a “special socket”, that is coded to supply that current using….. a strong magnet!!

See this forum entry and a few posts down. “pirpy” decided to use this knowledge to recode the flexi charger to 13A permanently.


In all fairness user “Crf” in the UK SpeakEV forum pointed me to this and I fully admit I thought he was pulling off a pretty decent April 1st joke, but it is really true!

Edit: as expected the Flexi charger has two relays so it can switch polarity. That was impossible to do in my granny charger, simply because there was no room for it.

4 Comments on “Granny charging (by Renault this time)

  1. Last week my “granny” charger (original Renault) started behaving strangely and stopping charge during the night. After some investigation I finally found out that my socket where “granny” charger is plugged is getting hot. Which means that Renault “granny” charger is very smart and besides reed relay for enabling faster charging also has embedded temperature sensor which detected faulty socket.

    After changing the socket everything again is functioning flawlessly. 🙂

  2. Nice to know the granny charger does have some safety build in. I wonder why…

    Charging with 10A or 13A is a bit silly when 16A is availible. Yes, 13A and sure 16A could melt a standard wall socket while charging. This could create a shortcut and even a fire too.

    Lets use magnets to higher the risks on fire during a nightly charging session. Adrenaline is the best drug! Legal and FREE of any charge.

    Please, change does cheap (__’__) wallsockets to heat resistant wallsockets and do NOT use those magnets!

    Unless you have a real good and trusty insurance, multiple ways to get out of the house…. and a way to remove those magnets without shocking yourself while the socket is melted or on fire.

    Because? …. the insurance will NOT pay when they see you have ..l., ‘ed with the wiring!

    • The magnet encoder is designed to be used by a 16A rated Legrand socket. Now if someone decides to mess with that…..

  3. Original Renault granny charger with magnet is 13A of which Zoe takes around 2400W – which is far from 16A.
    Of those, Zoe receives only 1800W (efficiency 75%) with around 8% charge per hour on our old Q210 Zoe.

    Without magnet Zoe is getting around 1800W from the socket of which it receives only 1000W with much lower efficiency (55%) and way slower charging time – around 5% charge per hour.

    Every good socket with 2.5mm2 wires is able to provide 2400W and I agree that 16A would be far more dangerous.