The "practical" difference is the amps a battery can safely discharge without venting or failing. Most quality batteries are 20A, but some are rated and tested higher. It is their tested value for continuous discharge that is important. Their pulse value is usually higher, but means little since you are not using them in a pulse capacity, in other words you are holding the fire button longer than one second [emoji4]. Typically, batteries with lower capacity (mAh) have higher discharge ratings, and those with huge capacity have lower amp rating... But it's a generalization, not a rule. The batteries I listed above are proven and tested to 20A ratings, and most of us here on VT know and trust them daily! Sent from my XT1094 using The Vapor Talk mobile app