Question about Battery Charger

[Newt]

I have an '05 TZX 200, it has a 3 bank charger.
It's been rather cold in PA the last few weeks, so I went out to the garage and plugged in my charger.

On my charger there are 3 groups of lights, the one on either end has maybe 3 or 4 redlights and looks like it normally does when I start a charge.

The set of lights in the middle only have one light on and it is blinking.

Can anyone tell me what this might mean?

[Newt]

Sorry for the double post.
I thought I lost the first post.

[dr. seuss]

with my charger when i let the batteries get too low it wont bring them back up..so maybe one battery isnt taking a charge is my guess