Compaq Prosignia VS from 1996. Has a dead Rayovac type 840 battery. These are actually still commercially available, for $21-$36 each.
But say, just for the sake of argument, that I wanted to instead replace it with a much more common battery type. The 840 battery says 4.5 Volts but doesn't say the current. I can easily buy a replacement battery pack for 3*AA, 3*AAA, or 3*AAAA batteries to add up to 4.5 Volts, but how do I know that I will have the correct current?
But say, just for the sake of argument, that I wanted to instead replace it with a much more common battery type. The 840 battery says 4.5 Volts but doesn't say the current. I can easily buy a replacement battery pack for 3*AA, 3*AAA, or 3*AAAA batteries to add up to 4.5 Volts, but how do I know that I will have the correct current?