Hey Mate,
Mine had the exact same issue, i left mine in the garage for 3 weeks and tried to start/open with remote and got nothing... i unlocked the door with a key but couldn't get the passenger door open lol. I had my mate jump start me and it worked first time you can do that as a temp fix but you will need to recharge it ASAP. I let mine charge for a day and its fine now, actually its AMAZING now... the ECU was obviously reset in the process !
The guy who owned it before me drove 2k miles a year and was 72 years old so went from 1st to third to sixth everywhere ! MY GOD did the ECU reset make a difference... i've fell in love with my zed all over again. Its like a new car... i did think it was fast when i first got it but it never really suprised me but now WOW
Also be advised when i jumped it the alarm went off when you complete the circuit so just use your remote to unlock as it should work then and turn it off !
Cheers,
Joe