On the positive face, for G1, add two non-polarity tubes on the board, no matter the polarity is positive or negative, the LED light will be lighted up.

As for G2, the mainly difference between G1 and G2 is, except the two non-polarity tubes, G2 has a resistor on the bottom of the board,So you can see the difference on their appearance. 

 
On the back face, as you can see from the G2, and this design is very useful for heat dissipation, when the temperature of led increase, can dissipate heat from the resistor in the bottom to the base so that avoid to overheat, not reach to the melted point of the tin, 100% the led head not fall apart and 100% never burned.

G1: the resistor of G1 is on the top near the led chip, it is on the middle board, when light on, not easy to dissipate heat, so easy to reach the melted point of the tin, that’s why G1 canbus led easy to fall apart into two parts.Meanwhile when the temperature of led lamp is too high ,the life time of led chips is shorter.

Inner part design of G1 and G2:

As for G2, from the single board which split out from the led light, then you find there are four constant current tubes inner, which on the back of each board, And this design is very useful, when the current reaches above 14v or 16v, then the constant current tube will adjust the current, reduce the current to avoid the led lamp burned.

As for G1, all the resistors are welded with the back of the top boards, besides the inside of the G1 canbus led have two big resistors, when light on, inner g1 canbus led 6 resistor generate heat,so the temperature of G1 canbus led is much higher than G2 canbus led, and once overheat, it will melt the tin point and make led fall into two part, and this is why we update the second generation to avoid this easy burning problem.