Is the Gaomon GARVEE powerful enough for tree work?

It handles branches and small limbs up to roughly 10 inches, which is most yard cleanup. It is not built for felling trees or cutting thick hardwood logs.

How long does the 20V 4.0Ah battery last?

Expect a few dozen cuts per charge in softwood and less in dense hardwood. Buy a spare battery if you plan long sessions.

Does it come with a charger and battery?

The kit includes one 20V 4.0Ah battery. Confirm the listing includes a charger, since some sellers ship the saw and battery only.

How does it compare with a 6-inch mini chainsaw?

The 12-inch bar cuts larger limbs and reaches further, but it is heavier and drains the battery faster. A 6-inch saw is handier for pruning and light brush.

Is the chain easy to replace and tension?

Yes. The side cover comes off for chain swaps, and tension is set with a screw or tool-free knob depending on the version. Check the chain after the first few cuts as it stretches.