No, all our cable is specified by the cross-sectional area of the copper conductor (in mm²) which is related to the current carrying capacity. Cable insulation thickness changes by manufacturer and cable type so you should never rely on outside diameter alone.

Yes, voltage drop is one of the most important elements to consider when designing your 12V electrical system. See our voltage drop calculator to help you select the correct cable.

The motors driving the compressors in these fridges tend to be quite sensitive to voltage drop, and if the voltage becomes too low it can prevent them from starting-up.  The fridge manufacturer's handbook will usually recommend a cable size for a given cable run length (from battery to fridge) and this can be much larger than you would expect (perhaps between 6 and 10 mm²). This large size is not because a high current will be drawn (these fridges tend to draw only around 3-4A); it is to prevent voltage drop from being an issue.