Battery dead after track day? Any thoughts?

[atombmb]

I have a UK Atom 2 with the Honda.  The last few track weekends my new battery starts the atom for the first track day but the morning of the second day I need to jump start the car or bump start it to get it going.  I have started to bring a charger with me to the track and put it on the car after each session.  Last weekend at Road America the battery lasted until the fist session of the second day and then wouldn't turn the motor over.  Got any ideas?

[positron]

Take your voltmeter and check for charge while running, should be in the 14v range. I had a connector fitting break at the starter from the alternator so it basically couldn't hear it. Was a 10-min 50-cent fix once I had the proper tools, but put me down at the track.

Or for whatever reason your not getting a charge. It'll pull this tiny battery down pretty quick with no recovery. If you have a wimpy charger it won't recover between sessions.

All this assuming your second battery is not crap and not knowing why first battery was changed.