Taipan wrote: ↑Tue Aug 20, 2024 8:35 pm
I'm with Yorick here, never jump a bike from a running vehicle. A spike can kill your ecu.
Well, you live and learn eh?. (Not that I've ever tried to jump start a bike with a car, but have done car to car many times). Puzzled as to why a car on tick over would have an output spike and why this isn't a problem for a modern car on the receiving end too. (Our 'laptop on wheels' car instructs you to have the 'donor' car running).
Car to car isn't an issue: the systems on both are designed to handle the outputs of batteries with similar specs.
But Car to Bike is not to be recommended because bikes aren't designed to accept current from car-spec systems, they're only designed, or rather, manufactured, to accept current from the rather meagre outputs of bike-size batteries and generators.
Taipan wrote: ↑Tue Aug 20, 2024 8:35 pm
I'm with Yorick here, never jump a bike from a running vehicle. A spike can kill your ecu.
Well, you live and learn eh?. (Not that I've ever tried to jump start a bike with a car, but have done car to car many times). Puzzled as to why a car on tick over would have an output spike and why this isn't a problem for a modern car on the receiving end too. (Our 'laptop on wheels' car instructs you to have the 'donor' car running).
Car to car isn't an issue: the systems on both are designed to handle the outputs of batteries with similar specs.
But Car to Bike is not to be recommended because bikes aren't designed to accept current from car-spec systems, they're only designed, or rather, manufactured, to accept current from the rather meagre outputs of bike-size batteries and generators.
Interesting, but a bit confusing - being a non-electrician I'd thought that 12v is 12v and things draw the current they need but that's probably a bit too i=e÷r
OTOH if I needed to jump start a bike, I'd use my Noco. Although from memory, if I hadn't added 'tails' from the battery I'd still have to take the tank off to access the battery terminals on the GS.
Doubt is not a pleasant condition.
But certainty is an absurd one.
Voltaire
I've had a tech do some tests tonight. It looks like battery failure only. Bloody hope so. Starter motor is fine, Starter relay in fine. He also has no qualms on jumping from a running car to bike. It seems some do and some don't.
Unlike the old wet lead acid batteries that would gradually die, gel batteries seem to fail almost instantly. They're often fine one day, shagged the next.
I rode the old Hornet from Kent to Oxford one morning to run a course. It started fine out of the garage, parked up to meet the trainee, only for the battery to fail when I tried to restart - it wouldn't even turn the motor over. Fortunately, I was right next door to a bike shop who ripped me off for a ultra-cheapo R*b H*nter battery that was equally dead just 9 months later. Yuasa went in. Lasted years.
FWIW, I finally replaced the OE Yuasa on my 62 plate Yamaha XJ6... yep, twelve years old.
Although from memory, if I hadn't added 'tails' from the battery I'd still have to take the tank off to access the battery terminals on the GS. 
