Vinnie is certainly right about SLA batteries. To extend useful life, a 12V SLA needs to be topped off with charge as much as possible, and discharge below 10.5V (even for deep cycle models) will permanently weaken them. It has nothing to do with memory effects. One way to avoid problems is to install a cheap signal-powered digital panel voltmeter across the terminals to keep a close eye on them during operation and charge cycle. Lasker makes a nice $25 model. Enersys probably makes the best SLAs in a wide range of sizes, but no SLA will survive repeated deep discharge.
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.
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.