The famous volt named Sparky is now over a half million miles, so I wouldn’t worry about a 10 year old battery. If you like the car, suck it up and fix it. The other option is to get a newer car and jettison this one, but that will likely cost you more than fixing the volt. I wonder if the loose bumper cover was a collision from one of your kids that broke the charger. With the bumper loose, you might luck out and just have a loose or broken wire (fingers crossed).
As for MM you really aren’t gaining anything by just driving it in normal except you get 12-14 miles of pure EV mode if driving along quietly once in awhile is important. Using MM to generate electricity at a cost of fuel only to use it later is no different than just driving in normal using that same fuel, in fact there are losses converting that motion to electricity to battery storage then back out to motion through the electric motor.
As for MM you really aren’t gaining anything by just driving it in normal except you get 12-14 miles of pure EV mode if driving along quietly once in awhile is important. Using MM to generate electricity at a cost of fuel only to use it later is no different than just driving in normal using that same fuel, in fact there are losses converting that motion to electricity to battery storage then back out to motion through the electric motor.
