R80GS electrics

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jeffsimants

R80GS electrics

Postby jeffsimants » Thu May 26, 2011 9:58 pm

Hello,
Problem!
R80GS 1992 - I've owned it for 18 of its 19 years and its always been extremely reliable.
Due to a move involving months of work, the bike was stored in a barn over the winter.
When brought out this week, the battery was dead - new last year. When fully charged up the bike started easily and rode smoothly.
Problem - when ignition switched on, the ignition & neutral lights appeared only briefly then went out.
When riding, any attempt to use indicators, lights or horn resulted in the ignition light coming while none of these ancilliaries worked.
Strangely, the bike ran very smoothly and the brake light worked as normal.
On returning home, I connected the Gunson charger which showed the battery to be pulling 5amps!
Is it damp or dirty switchgear, connections or is it alternator/diode board/regulator?
(I doubt the latter, as I can't understand why this would affect the ancilliaries & warning lights immediately on refitting fully charged battery).
I'm tempted to apply contact cleaner to switches and silicon grease to connections.
Any help would be gratefully received.
Regards.
Jeff Simants.

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Galactic Greyhound
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Re: R80GS electrics

Postby Galactic Greyhound » Thu May 26, 2011 10:36 pm

I think the battery is likely to be goosed. If a lead-acid battery is left in a discharged state for any period of time the plates become sulphated. This is a white crystalline surface formation which insulates the plates from the electrolyte (acid) resulting in the active area of the plates being effectively reduced by up to 100%. It is the plate surface area which determines how much current the battery can deliver. A voltmeter across the battery terminals will still read 12v but the battery will not be able to deliver its normal current. Any current it can deliver will only be for a much reduced period.

When you charged up the flat battery it probably managed to take enough of a charge to fire up the bike which then ran on the alternator output but it will not be able to supply the current required for both the ignition and lighting if it is badly sulphated. The plates may have become damaged due to overheating by trying to draw too much current from the reduced plate area when starting and/or being charged at too high a rate in their damaged state by the alternator. This could cause the lead oxide paste on the positive plates to fall off onto the base of the battery where it will short out the cells, cause self-discharge and show a high charge rate on the charger.

If the battery is badly sulphated and the bike is run the alternator charging circuit is at risk of being damaged.

First check that the main earth connections from the battery 12v negative terminal to the engine/gearbox are clean and sound. Then swap the battery with a known good one and see if things work OK.
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

jeffsimants

Re: R80GS electrics

Postby jeffsimants » Sat Jun 18, 2011 1:38 pm

Many thanks GG.
Relay & battery sorted it!
Jeff S.

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Galactic Greyhound
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Re: R80GS electrics

Postby Galactic Greyhound » Sat Jun 18, 2011 6:37 pm

Thanks for the update Jeff - glad to hear it's now working OK.

Regards,
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

wulfrun
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Re: R80GS electrics

Postby wulfrun » Sun Jun 19, 2011 10:39 am

I think the battery is likely to be goosed. If a lead-acid battery is left in a discharged state for any period of time the plates become sulphated. This is a white crystalline surface formation which insulates the plates from the electrolyte (acid) resulting in the active area of the plates being effectively reduced by up to 100%. It is the plate surface area which determines how much current the battery can deliver. A voltmeter across the battery terminals will still read 12v but the battery will not be able to deliver its normal current. Any current it can deliver will only be for a much reduced period.

When you charged up the flat battery it probably managed to take enough of a charge to fire up the bike which then ran on the alternator output but it will not be able to supply the current required for both the ignition and lighting if it is badly sulphated. The plates may have become damaged due to overheating by trying to draw too much current from the reduced plate area when starting and/or being charged at too high a rate in their damaged state by the alternator. This could cause the lead oxide paste on the positive plates to fall off onto the base of the battery where it will short out the cells, cause self-discharge and show a high charge rate on the charger.

If the battery is badly sulphated and the bike is run the alternator charging circuit is at risk of being damaged.

First check that the main earth connections from the battery 12v negative terminal to the engine/gearbox are clean and sound. Then swap the battery with a known good one and see if things work OK.
People often overlook the damage done to a flat lead-acid battery. It takes as little as 24 hours to do serious damage and, effectively, destroy one just by leaving it below it's lowest permitted discharge point. I've known plenty of people discover them flat (say) after winter non-use then think "I'll just recharge the battery and it'll all be fine". Never known it to work though! There are methods of de-sulphating them but they're not guaranteed and never restore full performance, even when they work at all. Moral of the story - disconnect the battery when storing a vehicle, make sure it's re-charged every month or two.
'82 R100RS (written off Nov 2013, by a dozy car-driver), Suzuki Bandit

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Re: R80GS electrics

Postby Galactic Greyhound » Sun Jun 19, 2011 9:31 pm

+1 on that Wulfrun.

You have probably saved the lives of a few batteries with that post!
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!


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