Battery power?

Most of my operating is QRP, mostly 2.5W and occasionally 5W. On 472kHz my transverter produces 12W for an ERP of 10mW. Although I currently use an old linear PSU, perhaps I should use a battery pack with a charger to use when the pack is not connected to the rigs. Mains borne noise is likely to be less of a problem. I'd be interested to hear your views.