Beijing-flavored intensifier (erhua is the giveaway). Placed before an adjective: 倍儿棒 (awesome), 倍儿亮 (super bright), 倍儿精神 (bright-eyed and full of pep). Xinhua 词典 lists it as 方言 for 非常.
culture
Immortalized in the 2014 Spring Festival Gala song 《倍儿爽》 by 大张伟 — a refrain of 我的心情倍儿爽 briefly made 倍儿 viral nationwide.
