This demonstration guide answers one field question about a battery that will not recover after deep discharge. Measurements come before parts, and the notes are not a generic equipment FAQ.
Diagnose before replacing parts
Start with load-test amps versus the battery spec after a cooldown. That reading separates a battery that will not recover after deep discharge from adjacent faults that share the same complaint.
If the measurement is out of spec, treat the starter battery as the primary path. If it is in spec, do not replace the starter battery just to complete a parts list.
Repair the failed system
The usual correction is the starter battery, installed to the documented spec for this complaint.
A demonstration shop records the finding so the next technician is not repeating a guess about a battery that will not recover after deep discharge.
Stop before you make it worse
Do not automotive batteries used as a "temporary" standby pack. That shortcut hides the original measurement and creates a second failure.
If the machine still fails after the starter battery is corrected, convert the visit to a broader diagnosis rather than stacking parts.
Written and published by Ridgeline Small Engine.