Surprise! 
You don't even have to be a hoarder! Just be a westerner with anything and chances are you have way too many batteries. At least I do.
Tonight, I am STRESSED by batteries.
I've got 5 car batteries- two of which are going dead.
2 Garden tractor batteries on their way out.
One of two 2 bike light batteries took a dump.
One of three rear bike light blinkies wont hold a charge.
Three smoke detector batteries need changing.
I can't keep count of my Canon DSLR batteries which are dying various slow deaths.
I've got multiple rechargeable batteries for my camera's flash which aren't getting the attention they deserve.
I've got one dental light battery that just died.
Just replaced the key FOB batteries for one car.
The batteries in my bike pedals just needed replacement.
The batteries in my computer surge protector / battery backup just got replaced.
This is not including all the batteries in my HF stuff- for example, my studfinder, which I TRY to take out when not in use, but if I dont, the battery corrodes the hookups.
Drill batteries- Two different drill brands, two different systems. One older system kaput, newer system barely hanging in there.
Electric start battery on my home generator- just needed replacing.
Battery backup in my car's antitheft system is shot.
You get the picture. I'm starting to wake up in cold sweats about batteries.
Did I pull the 9 volt battery out of my temperature gun when I used it 6 months ago?
How are the batteries in my wife's maglight?
edit- oh crap- I need to pull the 9 volt batteries from my laser levels I use to align cars.
Oh yeah, the red- dot batteries....
Some of these batteries are regular A AA AAA etc. - but many are expensive li-ion options.
If the TABSapocalypse happens tomorrow, I hope two things:
1. TABS will be around to enjoy it.
2. I will get to simplify my life and need fewer batteries