All things have an operating range...temp...RPM...altitude...humidity...etc
Electrical/electronic also has an operating range. There is a min voltage to a maximum voltage. Also there is a specification on other aspects of the voltage/current...more so for signal level for computers. Things like voltage spikes that in the pre-computers would not have been an issue...
So, the dead battery may be a victim of the real cause, which IMHO, suspect the alternator...but that could also be the voltage regulator(s) too
Be careful of just changing out parts...and...running the new part for a while...the culprit could still be there...to take down the new part(s)...chasing the tail so to speak...
Your comment of ABS and injector funniness is indicative of this. Both the cause and the possibility of it taking out other components and/or systems
-Ben
Picture of my rig1996 GMC SLT Suburban 3/4 ton K3500/7.4L/4:1/+150Kmiles orig owner...
1980 Chevy Silverado C10/long bed/"BUILT" 5.7L/3:73/1 ton helper springs/+329Kmiles, bought it from dad...
1998 Mazda B2500 (1/2 ton) pickup, 2nd owner...
Praise Dyno Brake equiped and all have "nose bleed" braking!
Previous trucks/offroaders: 40's Jeep restored in mid 60's / 69 DuneBuggy (approx +1K lb: VW pan/200hpCorvair: eng, cam, dual carb'w velocity stacks'n 18" runners, 4spd transaxle) made myself from ground up / 1970 Toyota FJ40 / 1973 K5 Blazer (2dr Tahoe, 1 ton axles front/rear, +255K miles when sold it)...
Sold the boat (looking for another): Trophy with twin 150's...
51 cylinders in household, what's yours?...