My wife has a 1999 New Beetle 5-speed manual 2.0 with 110K miles.
A few times ‘only when turning right’ the battery light has come one.
It loses power (bogs) but then when straightening out after the curve all is well.
VW Dealer said battery and alternator are fine, ground is good and secure.
Firestone said the same thing.
The battery is from Sears, they said the same thing.