I have had good luck with BATTERYSHIP.COM. I have bought from them for 3 years now. It seems the battery begins to lose a charge fast after about a year. I STILL use my TJ-37 daily. I hope this works for you. Hmm... I might be due AGAIN soon!
Here is the link you can copy & paste.
http://www.batteryship.com/htmlos/h...l=Clie+PEG-TJ37
Good Luck!