You don't need a multimeter to catch a dying battery before it strands you. Most batteries give some warning — you just have to know where to look.
Look at the terminals
A white, blue, or greenish crust around the posts is corrosion, and it's often the actual cause of a “dead” battery — not the battery itself. Corrosion breaks the connection long before the battery is actually worn out. If you see buildup, it's worth having it cleaned rather than replacing a perfectly good battery.
Check the date
Most batteries have a manufacture date stamped or stickered on top, usually a letter-and-number code for month and year. Most batteries last three to five years. If yours is past that and you live somewhere with real winters or real summers, it's worth testing before it decides for you.
Listen to the crank
A slower, more labored crank than usual on startup is often the very first sign of a weakening battery — well before it fails to start at all.
Notice the lights
Headlights or interior lights that dim noticeably at idle, or when you turn on the A/C or accessories, point to a battery that's struggling to keep up with demand.
The real test: if you've needed a jump start more than once, the battery isn't “fine now.” It's on borrowed time, and the next cold morning is when it usually picks to fail. We load-test the battery and the alternator on every visit (RR‑5), because a battery that keeps dying is sometimes actually a charging problem in disguise.