After 20 years of satisfactory service from my Boyer Power Box, my charging system only provides just over 10 volts at the (disconnected) battery terminals. This seems to me to be an odd failure mode. Any hints and tips would be most welcome. The bike died on a run and I made the mistake (I think) of buying an AGM battery to get me home. Now I read they need special chargers, so was that more money down the drain?
I use AGM batteries with Boyer Power Boxes on two machines (12V alternator equiped) and have never had any trouble with them.
Despite the warnings I also use AGM and have no issues.
I think (from testing I have done) that the clever charging systems do not provide a good output if they are not connected to a battery. By this I mean if they do not have a load, then the output they provide is undefined.
If you have another battery of reasonable size, then connect the charger to that and check again.
I have been using an AGM battery for a number of years without problems.
Hopefully Al Oz will comment on this as he understand these things better than I do.
Thanks all for the assurances. I'll go go the Vreg1 plus capacitor (just in case). It's June and we might have a summer soon so I want it on the road asap!
My first Boyer power box lasted about 9 years. I noticed the red charging light was not going out and checked all the wires without finding any faults. I bought another Boyer power box exactly the same as the old one and everything was working again as it should. Sometimes things fail. My Boyer ignition system has been on the bike for over 25 years and still works perfectly.
I did sell these 30 years ago but they failed too often considering their excessive cost.
I do not know of any issues with the AGM batteries. If any product in this area is sold for motorcycle usage and it says so on the receipt and it fails then you take it back whence it came.
I can test regulator/rectifiers and there is very little gained by running them open circuit, they are there to charge a battery, hence look at the battery charge voltage with and without lights on, you will soon see a short fall if such is the problem. Low output of reg/rects is the most common problem, they come up to charge voltage-no lights, as soon as the lights are on the voltage falls below usefulness. Another test that is worth while with when these devices are suspect. Replace the reg/rect with a basic bridge rectifier (the one you took off if you like) no need for a Zener as this is a test. Run the bike up with and without lights and if you can get battery charging with the lights on then all else is in good order. You could even ride home with your lights on with reasonable care ie no high revs.
Al's observation about regulator voltage drop when on load seems to be my experience. When I removed the battery and kicked the engine over with my Power Box connected to a voltmeter, I got 14v almost immediately. And it hung there for ages before I discharged the capacitor with a flash through a bulb. But with engine running, it only gives 10volts. Anyway I have ordered a reg from Al, so hopefully it'll be OK soon.