Posts: 129
Threads: 45
Joined: Apr 2007
As far as I know, this unit takes Qty(3) AA Batteries. At least mine does. I have the TI-2550.
Jeff
Posts: 620
Threads: 14
Joined: Feb 2007
Hello!
According to Joerg Woerner's site, all the battery pack contains is a single AA NiCd cell:
http://www.datamath.org/BP_Repair.htm#BP3
Greetings, Max
Posts: 901
Threads: 113
Joined: Jun 2007
I have two 2550III's in my collection. They are both at my winter home. My inventory says that the appropriate charger is the AC-9130.
I have a listing of the characteristics of the battery packs and chargers somewhere, but I haven't been able to locate it. I think the listing is on Gene Wright's site.
Posts: 351
Threads: 49
Joined: Mar 2008
Texas Instruments does not sell these battery packs anymore. If you can't find one on ebay, here may be the next best thing. This suggestion primarily hinges on one thing; is the BP1A battery pack of the same physical size and shape as the BP3? From the photos at datamath.org, it looks possible. It is possible to purchase new BP-1As, from ebay, and directly from a company based in Dallas. If the physical sizes are the same, it would not be too difficult to open up a BP-1A, remove two of the ni-cads, rewire the remaining Ni-Cad to the contact terminals, and glue it back together. Confirming polarity would be necessary.
Posts: 901
Threads: 113
Joined: Jun 2007
Here is another possibility. My inventory notes that one of my 2550III's has a nine volt connector soldered to the battery pack connector. I can't tell you about polarity at this time. I expect to go to my winter home in a week or so. I can look at the unit then and tell you what I see.
The idea of wiring in a nine volt connector is similar in concept to what users did with the TI-55. It used nine volts generated by a battery pack, but the connector was different. There were several battery packs of that general design -- the BP-7 and BP-8, for example. They used two NiCad AA cells and a circuit board to convert the output from the cells to a nine volt output. Finding one that works is not so easy these days. If the cells leak the circuit board was typically damaged beyond repair.
Posts: 416
Threads: 78
Joined: Mar 2006
Thank you all. I didn't expect so many experts on TI machines.
To solve my problem (surpassing it) I asked the people who gave me the calculator if they had the AC/DC charger: they did. I tried, but the calculator goes on showing all the blue digits lighting on and off, like they were running on the display. Typing keys shows some effect of the segments (so I assume they work) but the running doesn't stop.
The result is, I guess: BROKEN! Any ideas about the way to fix it?
-- Antonio
P.S.
I'm going on holidays, this evening (Friday 18.30, Central Europe Time), and for a week I won't be able to read your posts. So don't think I'm not grateful.
I'll read everything from today on when I'm back, on Monday 14.
Good summer to you all!
-- Antonio