Dodd preamp battery plays 40 minutes


I have a Dodd battery operated preamp. It sounds very good, but the batteries (four square units well seated in their alloted places) do not play more than about 40 minutes. At that time, the preamp starts beeping to be recharged. It recharges, but then again will not play through a whole CD. Any suggestions?

The Dodd has a switch on the front to select between two sets of batteries, but I understand that this is a holdover from an earlier design and that in fact the preamp automatically uses all the batteries before it asks for a recharge. Changing the switch position to the other set of batteries does not change things. The preamp is plugged in via its adaptor, and is supposed to disconnect the wall power when it is turned on, and then to reconnect to wall power for recharging when turned off. I realize the batteries may be faulty, but it's a new preamp and it seems unlikely. Any guidance is appreciated.
audiomole

Anyone with a Dodd Battery Powered Preamp: I strongly recommend buying the charger and LiFePO4 batteries referenced herein.  Run time is 40+hrs. and charge time is less than hour.  Don't even know it's battery powered anymore...except for the incredible quietness and dynamics...  

I stand corrected. Using the charger and batteries identified above, the batteries NEVER discharge! There is an LED display on the charger that indicates 5 levels of charge with 5 being fully charged, which with these batteries is 26.9 volts. In an effort to discover how much play time it would take for the charger to drop to level 4, I let the system play around the clock (volume at zero overnight) and after 3 days and nights, it still hadn’t dropped from fully charged level 5. So I got out my trusty multimeter and the battery bank was still at 26.9 volts!

The batteries actually charge faster than they discharge!

This is awesome! All of the benefits of battery power with none of the liabilities. These batteries also provide 12 Ah instead of the 10Ah that SLA or GEL batteries do.

Anyhoo, just a public service announcement for anyone with a Dodd Battery Powered Preamp or for anyone who was previously unwilling to accept a limited run time with one of the best sounding preamps of all time...well, that concession is no longer required! :)