Recharge symbol
Rockster in recuperation
Recharging is a process in which monsters will rest from a battle and recovers his health (unless you pay for an instant recover which costs crystals) the easiest battles will take you less time to recover, meanwhile the hardest battles will take you more time, meanwhile the same occurs to crystals.
Better habitats like the native camp will give you more recuperation discount meanwhile habitats like the lake gives you less recovery time discount