BritBike Forum logo
BritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorThe Bonneville ShopBritBike Sponsor
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
ShoutChat Box
Comment Guidelines: Do post respectful and insightful comments.
Buy BritBike staff a coffee
Buy BritBike's staff a coffeeStill here since 1996 serving BritBike enthusiasts..
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
Member Spotlight
iansoady
iansoady
Birmingham UK
Posts: 49
Joined: June 2005
Show All Member Profiles 
Newest Members
Sumpong, Hap Shaunnessy, Steve D, DaveG., stretch7
10790 Registered Users
Top Posters(30 Days)
franko 146
NickL 79
DavidP 67
Popular Topics(Views)
952,902 mail-order LSR
Forum Statistics
Forums34
Topics67,583
Posts676,355
Members10,790
Most Online14,755
May 5th, 2019
Who's Online Now
62 registered members (Alex Lynch), 383 guests, and 763 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Battery Failure #745147 08/10/18 6:31 pm
Joined: Aug 2018
Posts: 8
Bill Harrison Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
Joined: Aug 2018
Posts: 8
Hi,
have just acquired a 350 Goldie but have electrical problems. Initially the dynamo was seized but I've sorted this, the dynamo motors correctly and I've fitted a new voltage regulator (solid state) I'm still only getting a slight charge at lowish revs but more concerning is that 2 new lead acid batteries have failed whilst out riding. They drop down to 4.3 volts, won't charge and despite all efforts appear totally U/S. Could it be vibration? Any idea how to check if the voltage regulator is working?
Ta

Last edited by Bill Harrison; 08/10/18 7:32 pm.
Support Your #1 BritBike Forum!

Check out British motorcycles for sale:
British Motorcycles on e-Bay UK
British motorcycles on e-Bay North America
Re: Battery Failure [Re: Bill Harrison] #745181 08/11/18 1:57 am
Joined: Mar 2014
Posts: 669
J
Jerry Roy Online Content
BritBike Forum member
Online Content
BritBike Forum member
J
Joined: Mar 2014
Posts: 669
Originally Posted by Bill Harrison
Any idea how to check if the voltage regulator is working?
Ta



Disconnect the battery.
Get a 12 Volt headlight
hook the headlight up to the battery leads
Start the engine
Does the light glow at idle? If yes, rev the engine
If no, rev the engine
Does the light get brighter?
If yes, measure the voltage across the light terminals while revving the engine. It should read about 7 volts
If it does, alles ist in ordnung
If it doesn't, measure the voltage across the output wire of the dynamo and it's case
It should read the same as the leads to the headlight (roughly)
If it doesn't, read the voltage from the field terminal to the case
If there is no voltage, or very little, get another regulator or check the continuity of the field wire from the regulator
Hook some jumper wires to the battery, hook the appropriate polarity jumper to the dynamo case, (ground) and touch the other battery lead to the field terminal.
Do not leave it on for more than 15 seconds or so, and while it is connected, rev the engine and check the voltage of the dynamo output. (terminal to case)
It should go way up
If it doesn't, rebuild the dynamo. If it does, the dynamo is working and the fault of no charge is probably the regulator
Most importantly, make sure you wired the regulator correctly, they do not handle reversed polarity voltages well

For extra credit, BING "flashing the field" and ponder the vagaries of electrical components.

Have fun JR

Re: Battery Failure [Re: Bill Harrison] #745182 08/11/18 1:58 am
Joined: Mar 2014
Posts: 669
J
Jerry Roy Online Content
BritBike Forum member
Online Content
BritBike Forum member
J
Joined: Mar 2014
Posts: 669
Originally Posted by Bill Harrison
Any idea how to check if the voltage regulator is working?
Ta



OOp's, I double posted, so this is a total edit

Last edited by Jerry Roy; 08/11/18 2:00 am.
Re: Battery Failure [Re: Bill Harrison] #745195 08/11/18 10:31 am
Joined: Aug 2001
Posts: 5,169
R
Rich B Online Happy
BritBike Forum member
Online Happy
BritBike Forum member
R
Joined: Aug 2001
Posts: 5,169
Dumb question.....is the dynamo wired correctly internally? The bush wires must cross each inside the dynamo. If they don’t there will be no output from the dynamo, but it will motor. eek


Never underestimate the human ability to elevate stupid to a whole new level!.
Re: Battery Failure [Re: Bill Harrison] #745202 08/11/18 11:45 am
Joined: May 2004
Posts: 4,061
B
BSA_WM20 Online Content
BritBike Forum member
Online Content
BritBike Forum member
B
Joined: May 2004
Posts: 4,061
Yes they most likely failed due to vibrations.
You will need to fit a battery with AGM
Absorbent Glass Matt wich goes between the plates for mechanical support
or
Fit Cyclons which are spiral would like a big cap and being a spiral suffer less from vibrations.
Having larget plate area are harder to overcharge
Being sealed do not gas and do not self discharge.



Bike Beesa
Trevor
Re: Battery Failure [Re: Bill Harrison] #745293 08/12/18 2:32 pm
Joined: Feb 2012
Posts: 1,301
Kerry W Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Feb 2012
Posts: 1,301
My Cyclons died in no time at all..


No generalisation is wholly true, not even this one.
Oliver Wendell Holmes
Re: Battery Failure [Re: Bill Harrison] #745295 08/12/18 3:25 pm
Joined: Mar 2007
Posts: 950
Swan Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Mar 2007
Posts: 950
I found good information about magdynos, including "flashing", testing, wiring, and more, on this website when I had issues with my dynamo.


1966 Triton
1962 BSA DBD34 Gold Star
1966 Triumph Bonneville
Re: Battery Failure [Re: Swan] #745365 08/13/18 2:33 pm
Joined: May 2013
Posts: 5,748
Allan Gill Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: May 2013
Posts: 5,748
Originally Posted by Swan
I found good information about magdynos, including "flashing", testing, wiring, and more, on this website when I had issues with my dynamo.



Swan may well have hit the nail on the head, has the dynamo been flashed to the correct earth (positive/negative, depending how it is wired) it would explain the batteries being killed, is the battery fitted with an inline fuse? if it has been flashed the wrong way it would have blown the fuse.... least it will if the output is high enough....


beerchug
Re: Battery Failure [Re: Allan Gill] #748914 09/12/18 6:19 pm
Joined: Aug 2018
Posts: 8
Bill Harrison Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
Joined: Aug 2018
Posts: 8
Now the old original battery has failed. I was out doing plug chops, going quite fast in top gear, serious blasts, then some slight misfiring then oooggghh stopped. Turned on lights, back light illuminated , headlight on, everything went out, no spark (coil ignition), so I think this is about 4 batteries that have failed, so have ordered some dinky little 6 volt jobs that are gel filled-AGM as mentioned above, hopefully they will survive the battery eating monster!!!!

Last edited by Bill Harrison; 09/12/18 6:27 pm.

Moderated by  Rich B 

Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | DVD- Manuals & Parts books
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Powered by UBB.threads™ PHP Forum Software 7.7.3