Topic: Converting my H100S from 6V to 12V - One for TwoTired?

[CrisPDuk]

I though I'd posted this last night, but I can't find the thread anywhere, so I obviously did something wrong

So the trusty, and much abused, H100 has finally been stripped down to its component parts for a long awaited, and well deserved, thorough clean and overhaul.  Apart from requiring a new piston, a hone of the barrel, and a gasket set, the bike is mechanically in far better fettle than I expected

However, the wiring loom (especially the plug connectors) has definitely seen better days, and since the original electrics were never really up to that much anyway,  I thought I would investigate the possibilities of upgrading to 12V.
Whilst the existing alternator should be OK,  I suspect I will need different voltage regulator , and probably a CDI unit?  Items from a later 12V 4 stroke CG125 should be more than adequate I would have thought,  but what I’m not sure of is what alterations will be required (mainly with the charging circuit, I suspect?) when I build the new loom.

Do I build a straight replica of the existing 6V loom?  Or do I look at incorporating  aspects of that from the CG125?

All advice, comment, and/or assistance will be gratefully accepted

[CrisPDuk]

Anyone

[TwoTired]

Do you know the voltages output from your 6V alternator?  Why do you think it would be high enough to charge a 12 v battery or run 12 v components?

6 V wiring routinely carries more current than 12v wiring.  It shouldn't be an issue with a 12 v conversion.  The voltage difference isn't enough to be concerned about insulation breakdown.

Note that I no nothing about an H100, or what type of alternator it has.

Cheers,

[CrisPDuk]

Hey TT, how's it going?

I'm assuming (dangerous I know) that since it's effectively the same as that fitted to the later 12V CG125, give the right exciter voltage, the alternator is capable of churning 12V out.

Like most 6V bikes it uses two of the phases to run the engine and the third phase to charge battery and run the lights.  The headlight switch connects this phase to a hefty resistor to dissipate this charge when the lights are not in use.

To my way of thinking I can wire the alternator through a silicon rectifier in the same manner as my CB and have the thing running more reliably?

I suppose the only way to really find out is try it   My piston and gasket set arrived today, so engine should be ready for a bench run tomorrow

[bryanj]

Chris you could try the old Triumph way and just rectify the ac then fit a big zenner on a heat sink to stop the battery overcharging, you would normally have all coils in parallel to do that