A signal your 12V battery needs replacing

After swapping out my 12v battery for a new one. I realized there was a sign ahead of time (possibly) that could've been a signal that my battery needs to be replaced.

It has to do with the car alarm. I always had to be pretty close to my car to set the alarm. I mean within 5 to 8 feet. It was sometimes annoying, but I just thought it was because it was an older car.

Now after changing the battery, the alarm seems to be a lot sharper. I'm able to set it from a lot farther away. I'm still testing this out to see if it's my own imagination or not lol. But this was definitely something I noticed and could be a sign your 12v needs to be replaced soon.

Heads up, the way I found my 12v battery needed to be replaced was my alarm went off out of the blue. Then I went to start the car and all I saw was a flashing dashboard until the car was completely dead. Jumped the car, took it to the shop and got a new 12v battery...everything is back to normal and better now.

Forgot to add that the old battery was 6 years old (previous owner).

 

What would I be testing with this? The battery?

The mechanic I go to always does a load check with the battery and it came back positive before this happened. I should've added this to the op.

 

I don't think so, but I also wouldn't know. I'm the third owner.

edit: the car has been great though!