Ctek Multi XS3600 Hot while charging

Hi!
I just purchased my battery box setup.
1x ABR Sidewinder battery box
1x Fullriver DC105-12 AGM battery
1x Ctek multi XS 3600 Battery charger

Upon arrival I connected the battery to the battery box leads and saw that the battery meter wasn't full. So I connected the charger directly to the battery and left it for about 45minutes. I've noticed that the charger is warm-hot to he touch. The battery itself remains cool. I've googled around and found conflicting reports as to the normality of the chargers heat while charging. I was wondering if anybody knows if this is normal?

Thanks in advance,
Will