Disappearing SERV light

The SERV light on my Twizy came on the other day. The Twizy was fully charged, if I turned off Twizy, then light went off, If I then drove it, after about 5 minutes the light went back on. This was during the hot period a few days ago.
So I booked into Renault Bradford, they did a “B” service on it, then told me the SERV light wasn’t because of a service was due, but a fault, after I’d paid them. Hmmm
Anyway I wasn’t pleased about that, They then quoted me silly money to just look at the fault, I contacted another dealer, who rather amusingly had employed a technician from the Bradford dealer.
So I booked the car in, fully charged it. and today drove it to for 40 minutes, during which the SERV light never came on. It was raining, and nowhere as warm as when the light went on.With no light the garage wouldn’t have a fault to diagnose, so I came home.

I thought I’d let the battery go fully flat, then charge it up.

Does anyone have any ideas as to what triggered the SERV light and if it’s going to come on again?

Thanks

Julian

Not necessarily, but should be something simple and stupid…
Check rear side/brake light bulbs, maybee just change them and spray contacts with some WD40 or similar…
or… If the SERV light will trigger on again, just stop when lit and check every other bulb functioning
or… are hinges and the switch on charging hatch OK? (if this, then you can’t start again if you stop and try power off and on again)
or… Battery cooling fan is working when charging? (overheating the traction battery when discharging)
or… did they checked 12V battery state on “B” service …

Thanks Kuki

The fan works on the charger when charging, I checked the 12v battery on a classic car charger, it’s ok. I guess it’s down to a dodgy light or similar connector, but it’s good now.

Thanks

Julian