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 Conversion from 6 volts to 12 volts



Some people like to keep their 6 volt system.

Others like to convert to 12 volts because it means they can use much brighter bulbs that are also available off the shelf in any motorists shop and that it ensures good starting.

Some say its handy because 12v batteries are readily available and much cheaper - they can get a jump start from any modern car should the need arise.

With the advent of high performance electronic regulators a 6v system can be made to be much more reliable and efficient than it ever was.

Staying with 6V operation also gives you solid state zero maintenance convenience to your electrics, giving good battery charging and with modern low current consumption bulbs, good lighting at all practical speeds provided that the wiring is in good condition.


We have looked deeply into 12v conversions for 6v cars and motorcycles. Our research includes much testing to see just what works best.

Our 12v conversions bring you convenience and efficiency.


6v dynamos can handle a 12v conversion. In fact a dynamo is more efficient at 12v as it runs cooler. Ease of conversion depends on the type of dynamo fitted and whether originality matters to you. Your vehicles existing 6 volt starter motor will easily cope with 12 volts without any conversion so long as it is in good condition.

Some 6v items, a prime example being a petrol gauge are voltage sensitive. i.e. they will not work on 12v with out some sort of extra resistance in circuit. To determine this resistance value, measure with a multimeter the resistance between the battery connection (B) on the case of the fuel gauge and earth (the body of the fuel gauge). The reading obtained is the value of the resistor that must be fitted in series between the gauge (B) and the new 12 volt battery. The petrol gauge will then work accurately on 12v. This can also be done with other 6v accessories. 


  I have developed our 12v conversions to suit all 6v vehicles using original fittings, modified internally.

I have developed conversions to make a dynamo that works efficiently not a half hearted cheap conversion that works but is in fact very inefficient. 

Examples of our work are to be found on Austin Sevens, Ford and Morris Eights, Buicks, Cadillacs, early Citroens, Jowetts, BSA 3 wheelers  (4cyl and V twin variants), Vincent and BSA motorcycles etc.

So forget about keeping the 3rd brush and connecting diodes and resistors or 6 to 12v invertors. Forget adaptor plates and fitting later dynamos. Our conversions look exactly as original from the outside.


Please ENQUIRE about a 12v conversion for your vehicle to work alongside one of our electronic regulators.

There are two types of 12 volt conversion.

Basic conversion

Most 6v dynamos start charging at around 800-1000rpm so they are geared to the engine to suit.

A 6v dynamo that has been converted to 12v using a converter regulator and its original 6v armature will not start charging until about 1700 rpm. Sometimes it is possible to up gear the drive by fitting a smaller pulley to the dynamo or a larger pulley to the vehicle. In the case of geared or direct drive dynamos this may not be possible. This does affect charging at engine speeds BELOW 1700 rpm. 

It's false economy to try to cut costs in this department.

Some rebuilders offer this basic conversion but from experience, their customers are usually disappointed with the results.

For these reasons, we don't offer a basic conversion.

Six volt vehicles especially if low revving/used for round town driving or after dark benefit well from full conversion. 


Full conversion

OUR full 12v conversion includes a rewound armature to 12v specification, new field coils to 12v specification, brushes, springs and bearings to suit and a 12v electronic regulator so low speed charging becomes BETTER (lower speed cut in) than ever. This is a real bonus for low revving machines or where the dynamo is crankshaft driven at engine speed. 

Our full conversion is the ULTIMATE in 12v conversions.

As a rough guide, prices for our full 12v conversion to a 6v two brush ** dynamo start at £550.00* including an electronic regulator fitted inside your existing case (plus VAT if applicable to you) .

A full 12v conversion to a three brush dynamo (inc. two brush conversion) starts at £575.00* including an electronic regulator fitted inside your existing case (plus VAT if applicable to you).


* Depending on the make/model/size of dynamo

** Unlike some others we recommend our full 12v conversion for Lucas and Miller motorcycle dynamos as low speed charging can be a problem using a 6v armature. 80 watts or more are available and the dynamo runs cooler. Prices start at around £350.00 including an electronic regulator in your original case (plus VAT if applicable to you).

Please enquire about your particular vehicle

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