Yes, it's done. Or, the trickle charger that keeps it charged is of poor quality... and is trying to continue charging it even though it's fully charged now.... so it's service life will be shortened.
No.
The old battery was bad it could cause a power surge and plow the main fuse.
Bad battery.
I got shocked by a search protector which didn't feel good even though im 12 years old. I felt a very bad shock but didnt die even though its only like... 10 minutes after i got shocked. TIP: turn off the search protector then plug in the AC adapter or what ever it is... Then turn on the search protector. Could SAVE MANY LIVES! Im doing better after 15 minutes. Be SAFE!!! :D
bad cells usally the water in the battery gets low damaging the cell
You probably have a dirty carburetor causing that surge.
the engine to stall and surge at idle
Yes and No, It depends on what place it is or how bad it is.
No, a bad coil will not drain the battery.
There are 3 items that can be used for surge suppression measurements. Most of the plug in strips use Joules as a measure but this can be very misleading. Joules is a measure of energy. Energy is current (amps) times voltage (volts) times time (seconds) or E=I*V*t. Voltage during a surge is critical in determining if downstream equipment is protected. So low voltage rating are important. Current during a surge is important as this is a measure of how many amps are flowing diverting the surge from the downstream loads. So high surge current rating are important. Time is not generally critical, but is determined by the characteristics of the surge. For standard surge testing, the time is identical for the same waveshape. So Joules appears useful at first glance because it incorporates voltage and current in one measure. However, one can increase the joule rating by increasing the voltage (bad) while decreasing the current (also bad). Joules can also be manipulated by using waveforms that are not standardly used in the industry. So rather than use Joules, it is much better to look at the voltage during a surge and the maximum surge current a product uses and ensure the testing is with a recognized standard surge waveform.
bad alternator, bad voltage regulator, bad battery, bad connections.
Could be the battery is drained or bad. Could be battery connections at battery and or starter are dirty and or loose. Could be starter solenoid is bad. Could be starter is bad.