Sat for a month and it started fine!

[Dean76]

I left my i4 on the Lotus supplied trickle charger while I was away for 25 days and I came back to a new CEL (car started up and drove fine). I used my old OBD2 reader and couldn't get a code to appear (but also couldn't erase the CEL). After driving it around for a day the CEL disappeared. I think it had something to do with inadequate charging or maintaining of the battery charge while in my garage