The Consumer Council said on Thursday that power bank rental platforms lack pricing transparency, with one firm's fee rising by more than 100 percent depending on the location.

The council said of eight platforms it checked in the past two months, only two showed station charges in advance on the operation page and offered a fixed pricing model across all stations.

Prices for the other six platforms differed based on the location or partner merchants, with charges varying within a district and even just a few shops apart.

The council noted that a 30-minute rental fee for one platform cost between HK$3 and HK$6.8 at different sites.

A daily price cap varied from HK$24 to HK80.

Some platforms also required users to apply manually for a refund of their deposit for the power bank.

Council chief executive Alaina Shum added that all but one of the platforms showed inaccurate GPS locations or wrong station information.

She said the companies should keep their details updated and accurate as this is important to people who desperately need to charge their phones.

"When in urgent need of a power bank, consumers' phone battery is often critically low. Inaccurate navigation not only wastes time, but may also deplete the phone's battery," Shum said at a press conference.

"Incorrect station data could lead to fruitless trips and extra charges due to delays."

Shum went on to say that accurate information, such as station addresses, shop names and business hours, could prevent disputes between parties.