Shortly after buying my Twizy I discovered that despite being a 2015 registered model it was actually built in 2013 so was fitted with one of the earlier problematic chargers.
I soon found out my original charger wouldn’t charge when our solar panels were generating as the supply voltage pushed to around 253Vac. Also it didn’t keep the 12v battery topped up from the traction battery whilst parked.
Not much long after my charger developed what seems to be a common fault. It only charged the 12v battery whilst driving quickly. When ‘idling’ or plugged into the mains the 12v battery wasn’t charging and the battery indicator and STOP lights came on.
On reading the forum I got the impression for Renault to fit a new charger would cost in excess of £1000 so looked for a cheaper alternative. In the end the best option was to buy a replacement charger from Renault and fit it myself. The price for the replacement charger was £727.57 (2019).
As already mentioned my original charger was one of the very early ones.
The charger Renault supplied me with appears to be the latest version with the sticker suggesting it was made in this year.
Replacing the charger yourself is easy as with the exception of the earth wire, all connections are plug and socket.
CHARGER REPLACEMENT PROCEDURE
Raise the front of the Twizy on ramps.
Remove the front under tray (6 large bolts and 2 small ones / 13mm socket and 10mm socket).
It’s best to remove the centre bolts last to prevent bending the tray.
Both the mains cable and traction battery cable have quite complicated connectors on them. To disconnect them you must first slide back the blue catch then slide the black casing back whilst first pressing button 1 then pressing button 2. The connector should easily slide apart with minimal effort!
Unbolt the earth connection and disconnect both the mains cable and pilot connection.
Disconnect the 12v lead
Disconnect the traction battery lead.
Disconnect the communications lead.
Unclip any cable fasteners that would prevent removal of the charger and pull off the vent pipe (if fitted).
With everything disconnected, remove the four mounting bolts and carefully lower the charger, which is quite heavy. I’d suggest leaving two nuts, diagonally opposite, on just a couple of turns until final removal. You’ll need a deep 10mm socket.
Refitting the new charger is just a reversal of removal, making sure all cables are secure (blue tabs pushed in).
My workshop manual didn’t specify individual tightening torques so I just used standard ones recomnended for the bolt sizes. I also applied a spot of copper grease to the two small under tray bolts that had started to corrode.
On completion check all charging features are ok - traction battery charges when plugged in, 12v system at ~14v whilst running and no fault lights.