If you don't have any XT60 batteries, an AC XT60 wall power adapter may be your best choice.
Input: 100-240V AC 50/60Hz
Output : 12V 3.0A
Cable length is about 80cm
This thing does the job. Only issue is the cable wires are low quality. The XT60 connector has already broken off mine and I always pull the connector when unplugging, not on the cable.
This power supply is cheap and light, so ideal for travelling.
The 3A rating is an exaggeration though. At 3A use, its built-in thermal protection makes it reset after 15-20mins
At 2.5A, it gets very hot, but works no problems.
Ideal for charging small whoop batteries (maybe up to 8 at once).
A perfect travel companion for an ISDT SC-608