Fluke 8010A without NiCad Batteries

[gmilliorn]

While working on my HP counter, my Fluke 8010A died.  I had to dust off the Simpson
260.  Anyway, unlike most Fluke failures it is not the display, but the battery.  I've
already replaced it once, and it is a waste of money since it never leaves the bench.
But, the manual specifically says not to operate it without a battery.

I did anyway, briefly, to check that the batteries were the problem.  Seems to work OK.
However, the circuitry seems to be a standard constant current using an LM317.

Instead of replacing the battery again, it seems like I could just reconfigure the
LM317 to provide ~2.4V, since that is the fully-charged battery voltage, by adding
the appropriate values from pins 1-3 and 3-gnd.  Anyone ever tried that?

[Skimask]

2 fully charged NiCad's would be more around ~2.8v.

Google has been, and always shall be, your friend.

I've got 2 8012A's.  Basically the same thing.  Batteries shot, never leave the bench.  Put a 1/2 watt 100 ohm resistor in place of the batteries.  Didn't mess with the R's across the '317.  Still working after X number of years.  Didn't even solder in the resistor, just got it hanging there...

[tautech]

2 fully charged NiCad's would be more around ~2.8v.

Google has been, and always shall be, your friend.

+1
But if there is a tidy/elegant  for ~2.8 V that surely would be the preferred option?
Plus a sticker on the outside to remind you when the memory of the mod fades.

[gmilliorn]

Hmm, 100 ohms is certainly simpler, I'll try that, thanks!

Incidentally, I did Google and all I found was tons of complaints
about the display dying.  I must not have used the right
words...

[ModemHead]

Instead of replacing the battery again, it seems like I could just reconfigure the
LM317 to provide ~2.4V, since that is the fully-charged battery voltage, by adding
the appropriate values from pins 1-3 and 3-gnd.  Anyone ever tried that?

I did that on an 8050A.  It uses a 4-cell battery, so I reconfigured the LM317 for voltage regulation at about 5.6V.  Works fine and keeps the voltage regulation within original design intent.

[SeanB]

Mod the regulator or add 5 1N5403 in series instead of the 2 cells to drop around 3V to keep the supply happy.