Do remember tghis is a parallel 2 battery mech, not 2 battery series mech. Important is calculating your amp draw as the voltage does not "double" the voltage as a series mech will. Here's a mech safety poster that can help you out.
Edit: Oh, and note that's at a full charge of 4.2V. As you use the batteries the voltage will drop, changing the amp draw accordingly. A 3.7V nominal (what the battery is actually "rated" at, but is 4.2V with a full charge) can actually be a useful number to plug in when calculating your load on the batteries.
Edit: Oh, and note that's at a full charge of 4.2V. As you use the batteries the voltage will drop, changing the amp draw accordingly. A 3.7V nominal (what the battery is actually "rated" at, but is 4.2V with a full charge) can actually be a useful number to plug in when calculating your load on the batteries.