6 volt to 12 volt

[Plum]

Hi all I intend using two 6 volt batteries each rated at 8ah when linked to get 12volt does the ah also double your help much appreciated using Alton alternator which states 12ah recommended any thoughts

[ajscomboman]

No the amps stay the same only voltage rate goes up

[Greybeard]

I use a Motobatt MB9U which is 12v 11ah and fits nicely in the battery box of my M31. Good luck with the Alton - I sent mine back and rebult the dynamo with 12v internals. Its been fine (and quiet) ever since

Steve

[Plum]

Many thanks for the answer to my question it now makes sense Now I'm awake and thinking clearly
can not send unit back as shortened to fit with cp box oh well let's see just how much noise they make then test it reliability
Paul

[GOLDSTAR]

can you elaborate pse Greybeard, parts used, where obtained etc? kind regards

[Greybeard]

Goldstar. This was what I was referring to

http://www.jampot.com/forum/viewtopic.p ... se#p205579

Steve

[GOLDSTAR]

sorry I didn't make myself clear perhaps. I understood you had converted your dynamo to 12V and I was asking for elaboration on this, kind regards

[Greybeard]

The conversion I did was simply replacing the field coil and armature with 12v versions - British made ones naturally if you believe the blurb. I think I got them from Feked as I had some points built up to use.The rebuild was straightforward and I replaced the bearing and brushes whilst it was apart. A year or so on and there have been no hitches at all with the bike showing a healthy charge even at lower revs whch it never did when trying to squeeze 12 from the 6v dynamo. The only reason I went down this route is that the bike, M31 DL, has an electronic ignition fitted so I was relying on the battery for sparks (I had taken to carrying a spare battery in the panniers just in case and always had the battery on a maintenance charger). If it hadnt worked I would have fitted a magneto again, either a Lucas or a BTH if the pension would stretch to it. As the dynamo conversion was the substantially cheaper option, I though Id give that a go first and it did the trick - I can even use the indicators without worrying about power use

Steve

[GOLDSTAR]

Thanks for this, one more question, did you have any difficulty removing the coil retaining screw? kind regards

[Dave T_LAPSED]

Hello Goldstar, I changed a field coil a while ago. You need to drill out the staking or centre punching which stops it coming loose, then with the dynamo held firmly use your biggest screwdriver with a small adjustable spanner on the flat of the blade. Press down on the screwdriver with all your might with one hand and turn the blade with the spanner with the other. It worked for me, my fear was to chew the screw up and then it's "hello Mr Drill!" Fitting is the reverse.
The armature caught my field coil at my first attempt so I slackened the screw, wrapped some thin flat plastic from a blister pack around the armature, reassembled it all and tightened the screw up, it worked a treat.
Tighten the hell out of the screw and centre punch it to stop it misbehaving. Then you can have a(nother) beer !
They fitted these screws originally in a special press that tightened down on the bit so it couldn't slip out of contact then tightened the screw bloody tight!
Hope you'll soon be keeping up with current affairs, Dave.