I have been seeking this battery for a long time now and I've ended up buying back the one I sent with a new, boxed HS-PX557 2 yrs ago. I originally bought this gumstick from Partstore in 10-07 and the manufacturing date is 1-03 stamped on the end. I think I might have bought one of the last ones available anywhere at that time. I paid $18 plus shipping then and this one I got for $15. So far, it works great, charges up and lasts about 3 hrs. before it needs to be charged again. I can't remember how long they are supposed to run before needing recharging. The seller said she just uses the adapter for her 557 and has never used the gumstick. I had her test it and it came thru with flying colors. One note however-it took her 1 month to test it and 2 wks to send it! I was sitting on the edge of my seat!

i would guess in my cassettes they average about 7-8 hours. for some odd reason it doesn't seem to matter how old they are. the old wm-6 cadium does at least as well as the ni-mh1400'S.i think your getting about 1/2 of what they used to bring new. you might try the aaa batteries and the gummy together. i would be curious as to how much longer the combo would run.

My question is: If one uses both the gumstick and AAA attachment at the same time, which battery is depleted first? Also, I was guessing about the PB-S5A's running time after full charge. As soon as the green charging light on the front of the 557 turns orange, it has probably run about 3 hrs. however, there is still a bit of life remaining in the gumstick until it just simply stops. I was anxious to get hold of my former PB-S5A gumstick especially since the woman was not using it and as we know, they go bad after sitting for awhile. She took forever to test it and mail it to me having one excuse after another! This whole transaction was very aggravating to say the least. I hope the battery lasts! I have another PB-S5A which reads 2V on my voltmeter but I can't even light up a simple flashlight bulb with it nor does it seem to have any output. Any ideas here? Another question: I have a wall adapter with a minimum of 3V output which I could use to charge the good battery in the walkman itself. The PB-S5A reads on the label 2V @ 300mAh. Would charging it at 3V harm it or should I just stick with my Aiwa wall charger for the battery?