I also really appreciated the included second battery, which charges through a port in the transmitter itself; it meant a full recharge was never more than a few seconds away. (thenextweb.com)
Samsung is selling a replacement second battery for Galaxy S4 smartphone with a dedicated charger just for the battery itself. (gadgetguide4u.com)
Toshiba has promised a model with a hard drive and second battery in the base, which could help this issue, but will of course cost more. (digitaltrends.com)