Last weekend, I spent most of a Saturday replacing a chain on a motorcycle.
After trying to re-start the motorcycle, I discovered that the battery was no longer any good. It's been in use for several seasons, and I typically put the battery inside and on a trickle-charger during the winter.
Even though the voltage measure indicated full-charge, the headlight went dead while trying to crank the engine. And the battery couldn't turn the engine over fast enough to bring the engine to life.
Thus, I had to purchase a replacement battery.
I did delay the purchase somewhat. The weather went from warm-weekend to cold-and-snow-flurries during the week. And I gave the old battery another session on the charger...then tried to start the engine again.
That, and the variations in weekly schedule, kept me from being able to do anything until this weekend.
The new battery has been purchased, prepared, and charged. But it hasn't been tried yet. I'll see what the result is tonight.