If you got Rivas from L-F, they will tell you on the phone you can use them straight away now. The mfg in china used to send them uncharged, but things have changed, and the owners manual is no longer up to date.
I have 2 Riva kits, an eGo-t and I just sold an eGo kit. I prefer Riva, even if batteries dont last as long. They give a warmer vape. I go through at LEAST 4 batteries a day, so I figure a 2 month guarantee is covering my use. Plus Rivas were outlasting eGo's in working hours. So dont be surprised if you dont like the eGo as much. Price does not a good product make.
I leave my chargers plugged in, and the cord light is always green unless a battery is in the process of charging.