Mac Trackpad woes

OK, this is so annoying. My clicker button went out on my trackpad. Just try using your trackpad without a clicker. Dragging windows becomes very zen—like a bad lightbulb joke. So now I'm using inventive hand gestures (in both senses of the word), to compute. Old USB mouse to the partial rescue. But talk about making useless hand jive motions! #idiotsdelight

I don't think it's actually the trackpad, but the battery beneath....it needs "servicing" but I'm determined to keep it going as long as possible—they sometimes swell as they age, making the trackpad wonky. I wonder what's the longest anyone's ever kept a "Need's service" battery going? I seem to have good luck with MacBook batteries. My old 2006 MacBook battery only just died, luckily I had a spare, so I swapped it out. Nae bad—that battery lasted 8 years! Most average about 3-5 years. I was very good, followed all the battery rules.
 
But, alas, the newer MacBook batteries are sealed inside. I need a special tri-tip screwdriver (not a roast), for starters. So it's not a simple swap. Guess I need to hunt down a battery. Nae clicker on a trackpad is irritating to say the least. Also, this was a used MacBook, so I don't know how well the battery was maintained previously. And if the trackpad and battery are bad, then its costing what it's worth to fix it. Ugh. You know me and Macs, I keep them alive decades past their expiration date.