NancysToy
Motorbike Professor
Two amps for an AGM battery the size of the one in the Spyder is marginal, but probably acceptable. Be aware that it could very well shorten the battery life, though. Fortunately, it is unlikely to blow it up. A smaller battery would carry that risk. Two amps can easily damage a small battery, ballooning or breaking the case, and blowing the lead out of the plates. The high amperage can also cause premature sulfation.This charger does have an on-off floating feature with solid state protection so using 2 amp setting wouldn't that be ok? The company maintains its ok use for motorcycle batteries.
There are additional differences between something like a Battery Tender and your charger. The chargers intended for motorcycle use do more than just charge at a high rate, then "float" with a low rate charge. They use carefully programmed charging algorithms to charge the battery in a way that extends its life, reduces sulfation, and provides the maximum charge for the longest period of time, without damaging the battery in the process or overcharging. The Battery Tender, for instance, uses four modes for charging...bulk charge mode, absorption charge mode, equalization charge mode, and float charge mode. Other brands use similar, multi-step charging, sometimes with five or six possible modes. They is more complex than they look, and worth the extra money. Getting one extra year out of a good-sized battery can pay for one.