You Do Need power plug adapter while traveling from South Africa to Thailand.

Here is Why You Need An Adapter

The outlet and plug type used in Thailand are A, B, C and O and in South Africa are C, M and N. This is how they look like.

South Africa

In South Africa, outlets of type C, M and N are in use.

Type C

Type M

Type N

Thailand

In Thailand, outlets of type A, B, C and O are in use.

Type A

Type B

Type C

Type O