Regulator rectifier convers AC into DC for charging the battery

On a bike engine if you have low battery power when the engine is running (should normally read 14v across the battery) then the likelyhood is the rectifier is burnt out and will need replacing.

The rectifier regulator is an alternator equivalent for a bike engine to keep the battery charged while the engine is running.

Please ensure this is mounted ideally on an aluminium surface to help dissipate the heat and ideally if this can be mounted somewhere on the vehicle where air can pass over it, that is preferable for preserving the life span of regulator rectifier