Battery weak after ride - C Rapide

[clevtrev]

This bike this summer did a two day trip, and if you look carefully, you will see no charging system, an electric starter, lights. That trip was 600 Kms. The Shorai, that you cannot see, handled all that with no problem. The charger for the Shorai is small, can be carried easily, plug into mains,you can find one of those somewhere, it only takes about 20 minutes for a full charge. Who needs charging systems ?

 

[Monkeypants]

Trevor, you might have been a few kms from shutdown. The Shorai site provides a discharge chart , along with a warning not to go below 12.86 volts. If you are somehow able to maintain a battery above 12.86 volts at all times while running a dead loss system, then it will be fine. Drop below this and get the double whammy, problems on the road and a very expensive junk battery.
I accomplished this very feat last June when coming home from Crawford Bay in South Eastern British Columbia. My Norton charging system failed and after an unknown number of miles , the bike died. The point at which the charging system failed is unkown because it has an idiot light and the idiot in charge of the light did not replace it some time ago when it burned out. So it could have been non functioning when I started the trip, about 1300 kms total. Anyway, the voltage dropped below the critical point for Boyer ignition about 500 kms from home on the return trip. No problem, I have a spare fully charged Li 20pb /eq Battery in the pannier. At this point I still thought 20 pb/eq was the same as a lead acid 20 ah, which is about small car battery size in Lead acid.In reality I had about 6 AH in the Battery, though it did not even seem to go as far as 6 AH ought to.
The Li Battery made it about 40 miles down the road and then it was ignition off time again. I checked the voltage and it wa hovering between 12.5 with no load and limp mode 5volts with lighting load, so fully discharged. Fortunately the Li battery ran out of steam at the top of a several miles long steep hill. I was able to coast right into the little town of Osooyos which sits at the bottom of the long hill. Actually I coasted into the Dairy Queen parking lot, which was ideal. I was able to sit in the airconditioned DQ (very hot day) and slurp ice cream while my friends went down the street to purchase a big lead acid battery for me. They came back with the propersized YTX 14 battery, OE size for the Norton. It ran the bike about 400 kms to home deadloss, andstill had lots of charge left. The Li battery apparently did not like being fully discharged to 12.5 volts, and that was the end of it, it no longer holds a charge.

Glen

 

[danno]

Danno,
three years old can be very old on a small battery that is not used everyday.
David

Yes. I guess many classic bikes are used like this. I use it when the weather suits but wouldn't want to use it as daily transport.
I have an Optimate trickle charger that I occasionally connect up. Maybe I need to use that more often with lead/acid type batteries.

 

[Monkeypants]

danno, is your existing battery topped up with fluid?
It sounds as though you have quite a high draw on your charging system, though it depends greatly on the type of lighting used. Your ignition draw is going to be quite high with Lucas Rita, I believe it is around 30 watts at idle. You mention that you always run your headlight during the day. If it is a 55 watt Halogen like my main headlight, then you have 85 watts so far. Add to this another 15 watts or so for incandescent bulbs in the tailight and two speedo lights (big speedo)

This gives a total of 100 watts dead load on the charging system. While sitting idling in traffic all of this power is being pulled out of your battery. In fact power is being removed from your battery all the way up to balance speed, which might be 50 mph with this load. So the only time the charging system can build the battery voltage back up is when you are crusing above 50 mph. If you are on slow roads or riding in congested areas, you might not be spending much time riding at speeds that will charge the battery.

You can (and may have already) reduce this electrical load by using a pilot light for daytime riding. Paul Goff sells LED pilot light bulbs that draw next to nothing for power and are quite bright. Same with the speedo bulbs and tailight, if they are all in led then this will reduce the draw quite a bit.
So it makes a big difference if you have a bike fitted with al LED lighting and low draw EI ignition such as Pazon (7 watts at idle for standard Pazon) or zero draw such as original mag or BTH.
Your total daytime electrical load could be down around 10 watts with lights and ignition on or as high as 100 with the first scenario.
Obviously with just 10 watts of load your charging system will be working on the plus side at a much lower speed and for a much greater percentage of your ride, so this will be reflected in the battery voltage at the end of ride.

 

[Howard]

I did all these calcs 3 years ago, right down to LED indicator bulbs. Decided I could use a rebuilt dynamo with solid state regulator on my Egli and it would look neater than my alternator conversion. After persevering for 3 months, I put the alternator back on - in town I was spending all my time watching the charging light and changing down to keep it charging - if I wanted a fast revving engine, I'd ride a Jap 2 stroke. My decision was the dynamo just wasn't up to the task, 30 amps (360 watts) from the alternator means the system is charging at 30 mph in top, halogen light, electronic ignition, heated gloves........

My Comet now uses the dynamo and 12V reg, but it has a BTH, 40 W headlamp and LED tail, I don't use it for long trips after dark and I don't use lights in daytime, so that works fine.

H

 

[Monkeypants]

Howard, the best stock looking charging system Ihave encountered so far was the 2 nd to last generation of the Alton. They are single phase with strong magnets and an internal transmission which speeds up the works. They produced good power right from idle and hit 150 watts at about 2000 rpm , as near as I can tell. Unfortunately the tiny plastic gear in the transmission was not suitable for the load. One of the club members here had some gears cut in 4140 steel as replacements. He provided me with one and I intend to use it soon.
The current version of the Alton is decent, it puts outv150 watts as well, but at a much higher speed. Aside from the Alton, all other options which provide higher power are quite nonstock looking, and in some cases, rather unattractive.

Glen

 

[Howard]

Thanks Glen, alternator is on an Egli that I try to use regularly, so it's more about reliability than looks - a bit like me really.

H

 

[danno]

danno, is your existing battery topped up with fluid?

Says on top of battery (Rob Hunter brand) not to remove the filler seal even when charging.
Also that no refilling is necessary.
It was filled and charged at time of purchase.

LED looks like a good idea. I also have after market indicators from M&P fitted.
Having just checked the bulbs,strangely they don't have any specs on them but may be 5w at a guess.
My father fitted the indictors and there's a note written in the front of 'Know Thy Beast' saying that '5w does not activate flasher, 20w ok'.
There's also the orange indicator warning light fitted in the headlamp plus the red ignition/charge light.
Thinking about it that's a lot of bulbs.

I sometimes have to sit in traffic in local town centres and at times would have dipped beam and indicators on.
I can see this would be drawing quite a bit from the battery and at the same time not charging.

 

[Howard]

5 W not bright enough for indicators, more likely to be the 20 W mentioned. If you change indicators to LED you'll also need to change the indicator relay.

H

 

[vibrac]

I have a Walkernator on my road comet I think it looks good
You know what they say, if you have room to spit through the middle of a motorcycle, it aint right.
well you cant spit through my Comet with the alternator in place