If you charge it at a high amp rate you run the risk of warping the plates. These small gel batteries have thin lead plates.
Even though that charger has a 2 amp setting, and even though it says it is an Automatic Charger I would be cautious using it.
Technically it should charge @ 2 Amps until it senses the battery is fully charged, then drop to Zero Amps.
-If you do use it keep the interval short. 2 hours max for safety sake, if the battery feels Hot, or starts to Swell disconnect the charger.
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The Schumacher 6 Volt / 12 Volt 1.5 Amp/ Trickle Charger is hard to beat.
Check Walmart its about $20
http://store.schumachermart.com/sem-1562a.html