Boyer Battery Booster

I admire your creative nature, solving a problem that can, and has, caused injury. I appreciate that you are budget minded, and I'm sure that the exercise was rewarding and satisfying; one of the joys of owning an old British motorcycle is that you get to release your creative energies frequently, especially if you subscribe to the maxim of "don't fix it until it breaks". I have seen countless old motorcycles that I wouldn't ride any further then I could push them; a virtual quilt of many fabrics which would carbon date across a number of historic periods.

You have also added a measure of complexity and increased the probability of a ride ending failure. Why??? New electronic ignitions are actually less costly if you look at the intervening inflation, and more reliable, as was stated earlier in this thread.

I noticed a classic lead-acid battery mounted in your ride, a good point of cost saving, also stimulates the surrounding paint to abandon ship, no need for Zip Strip, and good for two seasons, so no need for a Battery Tender; cha-ching, cha-ching, the savings become overwhelming, perhaps the Norton is some sort of in-organic reincarnation of the goose that produced golden eggs?? I find the classic English expression: "penny wise and Pound foolish" quite ironic when it comes to English motorcycles.

I apologize for raining on your parade, and I'll back that up with an offer of a free analog Boyer, I think I have a Mk3, if not a Mk4, I have one or the other. If you are interested look me up, call me, and I'll get it done. I will not be at the shop on Monday 10/1. This offer is good only for the original poster.

Best wishes.

cliffa said:

Mike, The Mike Taglieri of headsteady fame ? well welcome!

Let me get this straight, so before starting you change the Boyer / coils to the "D" cell supply, spin up the engine and once started switch back to alternator power? If so that seems a very pragmatic approach, and the D cells are quickly isolated from any charging. One suggestion however would it not be better to use a single PP9 ( rectangular) 9v battery as they have a simple secure cap connection - i.e only two connection points and be less prone to vibration?

If you look at the price of the voltage regulator pdl999 suggests though long term it will work out cheaper than replacing batteries annually.

To me both have there merits.

cheers,

cliffa.

Click to expand...

Thanks for the kind words, but I think you're misunderstanding the circuit I showed. It is NOT designed to "change the Boyer / coils to the "D" cell supply, spin up the engine and once started switch back to alternator power." It's designed to add 3 more volts to the output of the regular battery during kickstarting. The regular battery and alternator continue to be connected and work normally.

So I don't see how a 9 volt battery could be used because you're still using the regular battery. That's theoretically putting out 12 volts. If you add 9 volts more, you're increasing it to 21 volts, which is way too much. The point of this modification is that the regular battery can drop down below 10 volts during starting, so if it drops to, say, 9 volts, that plus a 9 volt battery would give you 18 volts, which is still too much. If you used a 9 volt battery by itself to start the bike, it would be too little. Two C batteries, in my opinion, increase the voltage by 3 volts more, which is just about enough to prevent kickback, but you could also use 3 batteries to increase it by 4 1/2 volts.

I suppose in the long term anything that has to be replaced could cost more than something that never needs to be replaced (assuming that something never breaks, which is a big assumption). But if I buy an 8-pack of Ever Ready Energizer batteries at Home Depot, that works out to about $3.50 per year, which I think I can afford. (BTW, beware of buying alkaline batteries at convenience stores, etc. They are often fakes).