I have a gerbing heated jacket which is wired up to the battery and works , although a bit optomistic with a 1960 12v 99 and RM15? alternator.As the bike attempts to compensate the ampmeter goes beserk and will probably frighten itself to death.I'm thinking that I would like to see what is really happening and the meter needs to show the nett result . I think I should take the feed off the rectifier to ampmeter wire?.I did simplify the wiring 20 years ago and the charging probably bypasses the PSR8 switch which means less to go wrong.The jacket is radio controlled and keeps me warm on the lowest setting so probably only using 20/30w.
To show whether the alternator is keeping ahead of the game you could fit a small digital voltmeter across the battery. I have one on a Commando that is taken from the feed to the light switch and then earth. It effectively shows the state of the battery and if the alternator is coping then you would expect to see a steady voltage around the 13v mark. If it starts to drop, start switching things off. I have a fat wire running the length of the bike dealing with earth rather than the frame. (how does electricity complete a circuit through the headstock bearings covered in grease?)
Yes Robert. If you want to monitor the total balance* of power being used, the jacket wire should be on the same side of the Ammeter that is fed from the rectifiers output (as you suggest).
The other side of the ammeter should feed the battery only or any other electrical item you want constantly connected to the battery without showing its current consumption on the ammeter when in use...(not recommended but sometimes the stop lamp is wired this way)
* The sum difference of the alternators output and the batteries output (or charging current) vs the consumption of the bikes electrical loading.
Also note that the bikes ammeter is only there to indicate what current the BATTERY is receiving or giving out...NOT the generator's power output.
Hi les, Yes the ampmeter is mostly showing the alternator output (which is a bit distracting,and alarming!) After 20 years use I'm surprised to see the needle so far across the gauge ,thought the old alts are supposed to be feeble. Its powering coil ignition ,a Boyer box, indicators, a 40/50 watt H/L. and now a heated jacket. I'm expecting a big escape of Lucas smoke anytime. Re rigging the jacket feed from the rectifier output should give a better idea of the power balance (if there is one). The jacket has connections for heated gloves, do I dare??.
Don't worry about overloading the Lucas alternator as their "drooping" voltage characteristics means they can even drive a short circuit without heating up too much. In fact some wiring systems deliberately short out some coils to lower the magnetic flux across the other coils to reduce the power produced in them. So you will either have enough power to heat the jacket and gloves or not and this will be shown on the ammeter as a discharge from the battery if the alternator fails to produce enough power to balance the load, but no damage done to the electrics...as long as the wiring can handle the drain current that is....you can fit a safety fuse.........Les
Hi All, getting some use of the gerbing heated jacket now. Its still wired directly to the battery (with fuse!) and provides plenty of heat even on low settings, Its controlled via a radio link on the bars which allows adjustment on the move. My only issue is that to control the heat the unit uses an on/off switching at about 1 sec intervals and although its not wired thro the ampmeter the charging system tries to match the output and sends the poor old ampmeter going like a metronome, Not sure this would damage it ,probably the way out is to bridge the meter connections so can't see no evil. Ignorance is bliss.Thinking of upgrading from the old RM15 to 180 watts, expect to need a powerbox or similar to replace the old zener etc. Compressor powered air horn set found in the junk and relay next project.
You could wire it from the battery side of the ammeter (like the horn and stoplight) then the fluctuation won't show up on the ammeter.
Hi Ian, I thought that wiring directly to the battery would avoid it showing on the meter,but no, the meter is showing the charge systems response to the intermittent load. So noway round this one. Did about 50 miles early this morning in sub zero with a 50 mph headwind at times ,and stayed snug , well worth it.
Strange as that's exactly why the horn and stoplight are wired on that side. Although I must admit I'm thinking about dynamo rather than alternator.
I would be tempted to remove the ammeter from the system completely (leave it there for show if you like) If it's anything like my ex Commando a wire went from the battery (under the seat) to the ammeter, back to the ignition switch (Under the seat) up to the headlight switch and the coils etc. a lot of wires that you don't actually need and each connector giving you a potential ( scuse the pun) voltage drop or circuit break. My 3 phase alternator would do the job nicely and charge to a sound 14v at about 1800rpm loading up with lights was no problem and Oxford heated grips could be turned down in traffic when revs were not at a sustained 2-3000rpm. worth looking at whether your sidelight bulb is on when the head/main is on and off loading some smaller bulbs with LEDs. My personal opinion is that LED headlight bulbs are lacking in a quality beam. Like a lighthouse in the desert, brilliant but useless
Hi David, I did find that at 60 mph with very cold headwind the jacket heating effect was not noticed although felt snug enough on half setting (40w?).In slow traffic the heat builds up and the jacket can be turned off or down. The charging rate then soon drops off showing that the battery is not suffering too much.Will consider gloves or heated grips next. The crazy expensive Daytona boots have proved their worth and appear to be both waterproof and warmer than basic leather ones.A size bigger than I normally wear as I understand that feet spread with old age and the extra wiggle room helps the blood go round.
I have a Widder heated jacket. It was supplied with a thermostat and it can also be connected to pants (they are chaps, actually) and gloves. I ran a direct pair of cables to the battery with an in-line fuse. When riding my Mk III Commando during the day everything is fine but once it becomes dark things are much more challenging. Travelling at below 55 mph the headlight begins to shine less brightly and the heat in the Widder clothing diminishes. As the headlight becomes dimmer I have to ride even more slowly (I ride on mainly unlit, country roads) and consequently the amount of current going into the heated equipment will also diminish as the alternator provides less current at the lower speeds. So I end up going slower, for longer, with less available heat and light from the headlamp. If I turn up the thermostat the headlight becomes very dim. I suppose I have reached the limits of the original performance from the alternator, rectifier and zener diodes. Being realistic, an ammeter showing me just how much current I don't have might be useful .
Good luck and do let us know how effective the jacket proves to be - they are probably designed for much more modern machines which have more available power.
Colin Cheney, Leicestershire.
Hi Colin, Riding at night I suspect there would be little if any spare juice for the jacket. Night vision is much depleted by age so its something I avoid. At low power setting(20watts) the worst effects of cold are mitigated and at 40/50 mph on Aand B roads the loads would work for shortish journeys and I tend to run in 3rd more to keep the revs up.Probably would not have bothered but family bought me for christmas.
The Gerbing jacket has prooved itself so I am now adding some oxford heated grips, I have uprated the Alternator with the ES Commando 2phase unit.That was a bit awkward as the stator is not a simple direct replacement and the grip wiring is bulky .I will post again when I have done a decent trip.Still using the old dissy with a Boyer booster so this may be next as it seems difficult to get quality parts for these now.