NO! Your lane lights remain unlit. (They are fault lights) The only indication is a significant jump in amps as your battery begins to charge. For example, with the Earth X battery, my amps usually go up to around 16 to 18 amps. So while you are advancing the throttle, you should be looking at the ammeter for this jump.
This is correct.
The Lane A and Lane B lights are *fault* lights only, and neither should be lit in normal operations, including during the startup sequence and while the generators kick in. The ammeter is the thing you need to keep an eye on.
If one or both lights are ever lit or flashing, refer to the RV-12iS POH for a list of what the combination of lights means.
From
RV-12iS POH 7-12:
7.7.2 ROTAX 912 iS GENERATOR TRANSITION
After engine start, the Rotax 912iS generators will supply
power to the engine computers but not the main bus.
After the engine speed exceeds approximately 2,500
RPM for a few seconds the K1/K2 relay shown in Figure
7-7 will switch, Generator B will begin supplying power to
the main bus and Generator A will supply power to the
engine computers. This transition will be noted on the
Gen Amp Meter (Shown on the EFIS screen)
A table explaining possible Lane Fault light indications and related actions to take are in the POH, in Section 3-4.
Please don't operate the aircraft without being familiar with the contents of the POH.