What is the maximum diameter of spices it can grind?
Within 5mm in diameter. And keep the spice dry, otherwise it will affect its normal work.
How long it takes to charge and how long it works?
It takes about 2 hours to fully charge and it can be used continuously for 25-30 minutes (about 150-200 times of grinding) when fully charged, which is enough for daily use.
If I need to take it outdoors, do I have to carry it upright at all times? Otherwise it will start automatically?
No, it has a safety switch. You can turn it off when youre not using it.
If I need to grind the coarse particle, will it get stuck easily? How do I clean it?
It comes with a small brush included in the package that you can use to clean it after each use. If a large particle gets stuck, you can use a sharp object to remove it.
What is the storage capacity of this electric grinder?
Its about 100ml and you can refill it at any time.