Rechargeable (NI-CAD) "N" Cells spotted « Next Oldest | Next Newest »

 ▼ Frank Knight Member Posts: 68 Threads: 6 Joined: Aug 2007 12-03-2000, 10:45 AM Available Radio Shack under the Radio Shack brand, first time I have seen. ▼ Gil Petri (Brasil) Junior Member Posts: 12 Threads: 5 Joined: Jan 1970 12-03-2000, 09:50 PM What about the cells for an HP-97? They look awfully like regular size C, don't they? Does anybody know how to rebuild these? Can I replace these cells? Thanks, Gil Petri. ▼ Mike Sebastian Member Posts: 81 Threads: 4 Joined: Jul 2005 12-03-2000, 11:53 PM The HP-97 battery pack uses four "sub-C" batteries. Radio Shack sells them with solder tabs. ▼ Gil Petri (Brasil) Junior Member Posts: 12 Threads: 5 Joined: Jan 1970 12-04-2000, 03:44 PM What is the "mAh"? Does it make a difference or it's just how much the battery will last? Will the HP-97 use 1500mAh or what? Thanks in advance, Gil Petri. ▼ Steve (Australia) Member Posts: 241 Threads: 29 Joined: Jan 2008 12-04-2000, 05:44 PM mAH is the capacity of the cell. A cell rated at (say) 75 mAH can supply 75mA for one hour. Well, actually it's not that simple. the mAH rating is generally based on a 4 hour sidcharge (from memory) do this cell could give you 18.75mA for 4 hours. At 75mA it would actually give you slightly less than 1 hour service. You'll also find rates specified as 1C 0.5C, 10C, etc. These relate to a current of that multiple of the capacity of the cell. So 1C would be 75mA, 0.5C is 37.5mA, and 10C is 750mA (for the example above). The C notation is very commonly used for describing charging rates, and for describing the characteristics of a family of cells. AA cels were typically 400 to 450 mAH in the days that the HP41 was born. These days I can go out and get 1100mAH AA nicads. The same is true (but to a lesser extent) with the sub C size. I can't remember the figures off hand, but 2300maH (2.3AH) seems to ring a bell. The newer, higher capacity cells will give you longer running time from a single charge, but a charge will take proportionally longer. The best indication of a full charge is a rapid rise in temperature. I once posted the temperature of a full HP97 pack as I charged it. The rapid rise in temperature indicated to me that a 24 hour charge was WAY too long. It's also important to note that higher capacity NiCads are more sensitive to overcharging. If you look carefully into nucads, you'll find that they make nicads for rapid charge/discharge, trickle charge, etc. They vary in capacity since the use characteristics (partially) determine how they need to be constructed and where the tradeoffs in terms of capacity vs. ruggedness need to be made. Jerry Doctor Junior Member Posts: 28 Threads: 2 Joined: Jan 2008 12-04-2000, 12:59 PM I had the local Battery Patrol (I believe they have changed to Interstate Battery.) rebuild one last spring. Cost was only \$15. Steve (Australia) Member Posts: 241 Threads: 29 Joined: Jan 2008 12-04-2000, 08:57 AM You'll find that many small appliances (like cordless telephones) use packs made up of several N size batteries. Many used to be nicad, these days they tend to be NiMH. Look for replacements and tear them apart. :-) It may be a cheaper alternative. And yes, for the 97 (and HP 41 printer, cassette drive, disk drive, etc) the correct cell is the SubC. If Radio Shack AKA Tandy are anything like they are here, I would avoid them like the plague for buying anything. They are twice the price of normal electronics shops, and even they are twice the price you pay if you know where to go!

 Possibly Related Threads... Thread Author Replies Views Last Post HP 50g : More on best rechargeable batteries Miguel Toro 1 1,380 12-12-2013, 05:31 PM Last Post: David Hayden HP 50g : Best rechargeable batteries ? Miguel Toro 14 3,319 11-16-2013, 03:35 PM Last Post: Dieter Omnibook 300 battery cells Dave Britten 5 1,685 08-15-2012, 11:54 AM Last Post: Massimo Gnerucci (Italy) Rechargeable 2/3 AAAs in 41C-series Les Wright 7 2,097 06-14-2012, 12:43 PM Last Post: Eric Smith OT-N cells hide & seek Matt Agajanian 15 3,164 05-26-2012, 07:53 AM Last Post: Raymond Del Tondo Replacing Rechargeable Batteries on TDS/SMI RAM cards aj04062 2 1,129 04-12-2012, 11:20 PM Last Post: Geoff Quickfall HP41 battery holder, are there any CAD drawings? Ian Phillips 9 4,640 08-31-2011, 05:16 PM Last Post: Ian Phillips AA NiCad battery cells are now 1100 mAh rated Michael de Estrada 11 2,526 04-01-2011, 01:17 PM Last Post: Randy current draw from CR2032 coin cells Eric Smith 5 1,526 11-04-2010, 12:32 AM Last Post: hpnut 15C Spotted on National Geographic Program Jeff O. 0 681 04-16-2010, 01:27 PM Last Post: Jeff O.

Forum Jump: