The lead acid (alarm type) batteries used will drain down below the capacity of the float charger to recharge them. Remove the battery
pack; (remove screws, remove far left had side digit). Charge it for about 1/2 an hour with a light weight car or motorcycle charger. Put a
volt meter on the battery an see if it gets close to or over 12 volts. If it does, replace the battery and the float charger will work just fine. You can leave it plugged in for extended periods. It is made for that. The battery box will accomodate several sizes of 12v batteries. You can source the 6 v batteries we use in series at any decent electronic
store. They are Power Sonic PS-632 (3.2 amp hour, 6 volts)

I am haveing trouble with the batteries on my PST display. Battery life is now in the 2-4 hour range so I am looking at replacement. Upon research of the PS-682 battery the mfg suggests a specific method for the initial charge of the battery. Will the supplied charger PSC-12300A perform this task as required for optimum battery efficiency?

It is supposed to. We specifically use the Power Sonic chargers with their batteries to attempt to keep problems to a minimum. I would also cut the jumper between the 6 volt batteries and check and see if one of them is suspect. New battery packs are easily supplied.