is there a way to know if your battery is going to fail soon?

 

Probably start by having it checked.

 

If you have an amp meter, you should get about 12 volts with the car off. If the battery cannot maintain that voltage, you can bet that battery might not last more than a few more months.

 

Drill a hole in it. It will fail shortly



Seriously, what type of failure are you concerned about? Most of my car batteries seemed to just up and die. The glass mat battery on the other hand seemed to have less and less cranking power, especially in the winter.

 

Behavior is the best way to know outside of just checking it. Slow, weak starts (summer heat kills batteries, winter cold highlights lack of CCA), dimming electronics while in operation, both good ways to tell. Also, age, and some batteries have visual indicators on them.

 

The first time I think the car cranks one extra time before starting or cranks different than I remember, I go to the parts store, they hook up a meter, it tells you everything about the battery. That usually tells me if I have a bad battery or need to check a ground. They do it for free and it takes two minutes.

edit
exactly, they even will print out a sheet with CCA and whatnot at the local big box parts store for free.

 

Have to run a load test (what shops do) to find a battery that is just nearing the end of its life from natural causes. An ordinary voltage measurement can look fine (13-odd Volts) but then drop to nothing when the battery is under load (putting out decent current).