Battery

Standard battery:
-Elder models: 32 Ah, dimensions 230 x 125 x 165 mm
-SF models starting from 1973: 18 Ah, dimensions 175 x 125 x 165 mm (tighter cams and more revs in slow traffic, etc.)
Note that 18 Ah is also standard size.

MotoJouni said:
...in generator systems the charge and decharge cycles are longer than in more modern systems. ...
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All of the capacity is not only for starting a vehicle. Of course in the standard dimensioning of the battery capacity it has also more safety margin for things such more self-discharge in batteries of the era, possibly bigger battery for higher starting current, etc.

The standard 750 generator system don't charge anything at all under 1500 RPM.
In slow city rush hour traffic and similar conditions the battery can be discharging most of the time, or even 100% of time - the battery should be able to storage enough charge in these conditions - lights on. This kind of situation is normal in vehicles equipped with generators + mechanical regulators, the situation is quite different to modern alternators. This is why vehicle batteries often can have lower capacity in systems equipped with alternators.

-Jouni
 
Absolutely - goes without saying on an SF. The genny/reg is very reliable and produced a lot more watts than early triple alternators did once on the move, but the constant loss at idle was always its weak point if you ran a small battery.
 
The battery in the photo is safe to use in any Laverda. Regulators control the voltage for charging the battery it is a very very small amperage that the bike's charging system feeds to the battery. Trickle charges are very low amperage rapid chargers much more. As long as you keep the battery fully charged the one in the photo is capable of providing 200 CCA (cold cranking amps)it will start every time.
 
🤣🤣🤣 Too bloody true! I never had a flat battery until the battery was dead and ready for a replacement anyway. It's not as if we sat at red lights at night for hours on end.
 
I used a battery from a 1977 Honda 400/4 in my 750 Egli for many years, it was very small in physical size, installed due to space limitations, but the parameters of dynamo and regulator are identical, it was only 10 amp/hour, it never gave me any trouble whatsoever, that included at least six months of a 25 mile each way urban commute (read crawl).
CLEM
 
piranha-bro2 said:
Sorry, don't understand your comment, Jouni? Are there regulations regarding vehicles what have a 'total-loss-at-idle' charging system?
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I mean different regulations in different countries, no matter what kind of charging system a vehicle has.
For example headlight has major influence to average loading of charging system.

Say a bike has H4 55/60W headlight bulb. It must be on all the time when driving in Finland, just a couple of exceptions to this rule.
No matter how sunny the weather is, middle of city, etc. For example in Clems case, if it would be in Finland, it must be on all the time.

I also think that early triples are designed to regulations of Italy. I think they try to use headlights as less as possible.

-Jouni
 
I've never riden with day time lights, it's not law here in west oz. As I don't ride at night it's been a long time since I've used my head lights.
I do use them if the conditions are shitty but thats very rairly.
I have a Kawasaki 250 alternator fitted to the 1200 so no shortage of watts and also low wattage HID headlights, 35 watts I think X 2.
Took the Motodd out yesterday and for the first time I had to use a power pac to start the bike and when I got home put the battery on charger.
Hope that my at least 6 year old lithium battery isn't at it's end of life. It''s probably on the small side [290cca] as it's never cranked the H/C motor over at full speed but has always started.
When it didn't crank the motor over yesterday after the attemp it showed 11,8 volts. After running it for 10 mins it read 13.8 volts and started the engine no problem after that. I'm thinking the cables are on the too small size as they get warm so the main problem of slow cranking could be those.
 
Hi Cam, I checked the voltage this morning after charging it yesterday for an hour or so and it had 13.8 volts. Turned the motor over a couple of time and the reading was still 13.8.
I do think my problem is too smaller cables as the starter cable was feeling warm.
 
There are plenty of LED lighting options available now that are bright and use barely any amps. I have my eye out for a day running type that will look ok on the SF. All new cars have a separate day running light (some weird and wonderful LED designs) separate from the headlight, so it appears that this is allowed by the strict EU regulators and must be ok for a bike as well.
 
I'm running twin LED H4 conversion bulbs in the FSQ - they look very bright and the cutoff system looks to work fine - wattage is WAY down now; I'm running relays even though they don't need them - if I want to convert back to H4 the system is in place. In the past I've run twin 55/60 H4s from the SFs genny no prob, but used to switch one of the low beam H4s off in the city, day and night.
 
motoddrob said:
Hi Cam, I checked the voltage this morning after charging it yesterday for an hour or so and it had 13.8 volts. Turned the motor over a couple of time and the reading was still 13.8.
I do think my problem is too smaller cables as the starter cable was feeling warm.
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Yes, the original Laverda starter cables are a bit on the skimpy side. My Jota used to get hot cables on occasions when it needed a bit of cranking to get going. So I replaced the cables with fatter section welding cable (don't remember the actual size) and it improved starting. Don't forget the battery earth cable too. There's not much point having a beefy cable to the starter motor if you still have a scrawny little earth cable.
 
Yeah a mate of mine made the cables for me when I rebuilt the Motodd. At the time I questioned him about the gauge but he reckons they were ok.
I don't have alot of room to run beefy and non flexable cables either. I'm thinking I'm going to have to look into this futher.
 
Check out Todd's beefy battery cable! Then again, he's got a long run to cover. I'll need to make up some good size battery and starter cables for the SFQ.
 
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