I don't have any real measurements to back this up, but someone might find this anecdote useful.
I feel like my 102's AA battery life was much better after I cut out the internal NiCd cell. This idea is supported by the fact that it again seems to go through batteries faster since I replaced the backup battery with a new one. Worth noting I run the machine on Eneloop NiMH cells, not alkalines. On Tue, Apr 27, 2021, 20:51 Peter Noeth <petern0...@gmail.com> wrote: > I know this has been discussed before, but I was doing some testing on my > T102 regarding current drain to gauge external battery life. I made an > external 4D cell alkaline pack I use when watching TV and playing with the > computer a few years ago, and was thinking of upgrading the capacity. There > is no convenient A.C. outlet near by to my viewing position, hence the > battery pack. > > I measured this on a 32K Tandy 102 w/REX installed. > > - 0.4mA - Computer off, no peripherals connected > - 66.5mA - Computer on running a BASIC program, no peripherals > connected > - 67.2mA - Computer running a BASIC program and printing to my DPU-414 > thermal printer > - 71.8mA - Computer running REXMGR, no peripherals connected > - 114.7mA - Computer running a BASIC program, printer connected but > powered OFF > - 130mA - Computer running a BASIC program with Unitek Barcode Wand > connected > > I am sure a M100 would give similar results, but maybe a little higher in > some cases, due to the T102 being mostly surface mount components and the > circuitry optimized somewhat over the M100 > > The surprise was the marked current increase with the printer connected, > but powered OFF. There is obviously some sneak current paths if the printer > is not ON. Likely in the printers Centronics interface chip. This is good > to know if trying to maximize battery life. > > The current draw increase with the Unitek Barcode Wand connected was > expected, due to the fact that it has a very bright red LED, that is on all > the time. The RS Barcode wand likely draws less when its button is pressed > to turn on the dim LED. I like the Unitek wand better, as it reads codes > that are not black on a white background, like on food cans and potato chip > bags. Radio Shack just private labeled the HP wand for the 41-C calculator, > which was low power and expecting white paper barcode labels and program > listings. > > Regards, > > Peter >
