6v-12volts?

Originally posted by Barry Read
how esay is it to convert a 6v carrier to 12volts.
obviously change the battery, but what else?:

All the bulbs!

I've done it for a F30 but this had a modern(ish) diesel fitted so came with a 12V alternator and starter.

You can put 12V on the starter as its duty is very low but it may give the ring gear some grief as the pinion is slammed into it with some serious force, the starter relay will need to be replaced with a common 12V type too.

In the case of the F30 I made a regulated 6A convertor to supply a stabilised 7V (a fully charged and charging nominal 6V battery is 7v~7.2V) for the original 6V instruments.

You will either have to select your own high wattage ballast resistor for the ignition coil, or preferably replace it with a modern 12V type.

I have heard tell that the original regulator can be set up to 14V for a nominal 12V system and the dynamo will make that voltage given its head as it is limited only by the regulator setting. I have never done this.

Incidentally, you should be aware that vehicle electrics whilst being referred to as 6V or 12V are in fact never this in real life.

A 12V lead acid automotive battery (you can halve the figures for a 6V system) will rest at some 12.5V - 12.7V, it will drop to some 9.5V - 11V when cranking and should be maintained by the charging system between 14.2V and 14.5V when on charge and full. A digital meter across you car battery will show these readings.

It is normally accepted that a single lead acid cell, it matters not of what size however, is therefore at 1.97V fully discharged and 2.4V charged and on float charge.

Here's a hep of gen on automotive batteries:
http://www.uuhome.de/william.darden/index.htm

R.