Dodd PreAmp batteries not charging

Please help, my Dodd pre received new batteries last year which powered my preamp nearly all day long, now the batteries only last about 20 to 30 minutes. I exchanged chargers with a Dodd phono pre but without any results. Could the batteries need replacing this soon? I usually listen to my system 5 hours. Week. Any input is appreciated 

You may try contacting this guy. It seems he’s got experience, regarding the batteries and chargers, that work in your pre: Perhaps one of his, "Ultracapacitor" supplies can work in your application. Here’s another, much earlier, thread on the subject: