Dood pre amp

I’m having problems with my dood pre amp. I replaced batteries 4 months ago because the (4) batteries I had in it for 9 months started to give me only give 45 minutes of run time. Thinking it was the batteries I replace them and now these 4 month old batteries are doing he same. The original batteries were 5 ah and Thought about getting 7 ah, but realize there is a problem somewhere else. I have the dood phono pre and it charges fine and have swapped the chargers to see if that was the problem but the preamp doesn’t care it still will only function last time was 20 minutes. 

I really like like this pre amp and phono pre and would like a solution, anyone have any ideas?
Dodd pre’s are a finicky lot and now that Gary is gone it will be tough to service them. I have a friend that owned one and like you he had alot of problems with the batteries as well as tryijg to find the right fit with amps. Its a shame as they do sound very good. Best of luck with this preamp.
Danny Richie might be able to help you with that.  He and Gary were close and I could be mistaken, but I think Danny was helping some people with his products.
audiothesis is right, Danny Richie is the guy to contact. He's at GR Research.
Thank you, I’ll give Danny a call.
I checked out the GR sight and some Dodd owners are using upto 100ah external batteries. I might try that.

After reading about this problem I checked the 4 old batteries I replaced and they all had 12.7 volts or better. I was impressed after them sitting outside for 4 months. I installed them in my pre amp and it’s working fine, meanwhile charging the newer (4) batteries with my motorcycle trickle charger... dang I like to tinker, but want to Come up with a better solution than this? Anybody want to comment or add a better solution I’d welcome all advice