The short answer is no, you cannot fix a shorted battery cell. When a cell becomes shorted, it means that the positive and negative plates inside the cell are touching, causing a direct short circuit.
What causes a lead acid battery short circuit?
The following mainly analyzes the lead-acid battery short circuit caused by excessive charging current, charging voltage of a single battery exceeds 2.4V, internal short-circuit or partial discharge, excessive temperature rise and valve control failure, and summarizes the treatment methods of lead acid battery short circuit as follows:
Why are so many lead acid batteries'murdered'?
So many lead acid batteries are 'murdered' because they are left connected (accidentally) to a power 'drain'. No matter the size, lead acid batteries are relatively slow to charge. It may take around 8 - 12 hours to fully charge a battery from fully depleted. It's not possible to just dump a lot of current into them and charge them quickly.
Personally, I always make sure that anything connected to a lead acid battery is properly fused. The common rule of thumb is that a lead acid battery should not be discharged below 50% of capacity, or ideally not beyond 70% of capacity. This is because lead acid batteries age / wear out faster if you deep discharge them.
When should a lead acid battery be charged?
It's best to immediately charge a lead acid battery after a (partial) discharge to keep them from quickly deteriorating. A battery that is in a discharged state for a long time (many months) will probably never recover or ever be usable again even if it was new and/or hasn't been used much.
What voltage should a lead acid battery be at 0%?
Be sure you look at a table that correlates resting voltage against SoC and not the voltage under load. If you see a table with 10.8 volts at 0%, you are looking at a table for under load voltages. A battery at 10.5 - 10.8 volts at rest is probably damaged. A lead acid battery should never be below 11.80 volt at rest. ↩
Yes, a short circuit can damage a battery, especially if it leads to excessive current flow and overheating. It can result in internal damage, reduced battery life, or even a hazardous situation such as a battery explosion. Can a 12V battery short circuit?