The Consumer Council says higher battery capacities do not necessarily correlate with longer battery lives in portable fans. As the hot weather continues, the council has tested 18 models of rechargeable portable fans that come with price tags ranging from HK$58 to HK$339 for both handheld and neckband models. It found that some models with a low battery capacity but high voltage ran longer than those with a high capacity and low voltage. The watchdog further pointed out that a more expensive po...