Xiaomi sells portable chargers, also known
as Mi Power Bank, with different battery capacities ranging from 5000mAh to
20000mAh and even has a 10000mAh Pro version. Some significant features of the 10000mAh Pro include the product being
much thinner than their 10000mAh model, the time saved to charge mobile devices
(such as Android) and to charge the portable charger itself. The 10000mAh Pro
also have high density batteries and has a two-way fast charging and it is
priced at $35.

Mi Power Bank is sold worldwide and is very
well known (and commonly bought) in Singapore. Some of the interesting
promotion strategy Xiao Mi used are:

a premise that resonates with your target audience, where they offer high specs
at low prices.

fan festivals and local meetups, where they build rapport within the local community
and growing the fan base by encouraging fans to invite their friends along.

forces with like-minded brands to build hype, where they found new avenues of
outreach in strategic partnerships which exploit the combined clout of both
companies to generate word-of-mouth.