[77newell]

Dom: If all your 12V lights are doing this at the same time the problem must be something they all have in common. Assuming you change nothing (like having some 12V usage switching on and off randomly) then either the supply of 12 volts (your charger or inverter/charger) is raising and lowering voltage for some reason or the ground to the charger has got a bit of variable resistence in it (when this happened to me it was the lug where the ground cable connected on the charger)