Importance of TiBook Backup Battery

My nearly eight-year-old 1 GHz Titanium PowerBook has over the past couple of years exhibited some crankiness, not show-stopping but somewhat annoying. I knew that some of it was related to the backup battery which no longer took a charge and was low in voltage. Unlike the desktop Macs, though, replacing the battery is not a case of slipping another dry-cell Lithium battery into the machine.

A week or so ago, I finally ordered a new battery to replace the incumbent. Since Panasonic quit making the cell in 2005 after almost four years of production, one has to find other sources, one of which is iFixit. What is required is removing the supporting circuit board the cell is soldered to, unsoldering the old cell and soldering the new cell into place. After getting the new battery in place and letting it charge overnight with the main battery out, I began to see the disappearance of a number of annoying behaviors, some of which I didn't attribute to the backup battery.

In no particular order, these behaviors included the following:

• At boot, even restart, backlight set to minimum value, making verbose boot useless, unless preceded by a PRAM reset. (battery suspect) Now with the new battery, this does not occur.
• Inability to boot to Super Drive (this was a replacement I installed about a year ago) or select it from the Boot Manager. (not a battery suspect, I thought there was some subtle incompatibility with the newer drive) Now able to boot to the Super Drive if needed.
• Inability so swap batteries while sleeping. (definite battery suspect and the best test of that battery's capacity.) Works like it's supposed to now.
• Power manager does not give a warning on low main battery before putting machine to sleep. (did not suspect backup battery on this one). This now functions correctly.

I post this only as an object lesson regarding annoying misbehaviors in a PowerBook and how they were corrected and my TiBook was returned to better mental health (no such prognosis on its owner, though).