overcharge spike

[duTch]

 Can't offer suggestions about your issue yet, but I'm having a similar thing that I haven't managed to yet identify....had a headlight fuse blow a couple of times but not for a few days now- keeping tabs on this...

 Someone on here posted a link a couple of years ago about resettable fuses like these below, they don't fix the problem, just saves on fuses (just an example );-


 http://www.ebay.com/itm/Marine-Resettable-Blade-Fuse-Manual-Circuit-Breaker-5A-7-5A-10A-15A-20A-25A-30A-/311886307406?var=&hash=item489ddf604e:m:mtiUI4yBUP_DXSUtOQ9SoXA
 

[BSA500]

More testing... as before no blowing before the headlight is on. I watched the ammeter as the revs increased and it flicked into the positive a couple of times then a 4 amp flick and fuse gone.

[BSA500]

It goes to over charge because the generator is feeding into a fault.
You are reading the output from the generator, not the battery.
Is your light circuit connected to the generator or the battery side of the ammeter?
If connected to the battery side, this will happen.

Its always been wired this way so does this suggest a fault that has occurred in wiring or reg?

[BSA500]

Anyone suffered similar issues and cured????

[mikeb]

It goes to over charge because the generator is feeding into a fault.
You are reading the output from the generator, not the battery.
Is your light circuit connected to the generator or the battery side of the ammeter?
If connected to the battery side, this will happen.

Trev I think i get what you are saying - if the lights are connected to the battery side of the ammeter then the extra current of the lights (and battery charge current) could show a high reading as the genny/reg tries to power them both (yes?) especially when the revs are up.

and there must still be a fault, or two, to account for the sudden spike. And weird that the DVR2 will allow such a lot of current to flow out of it. however if the fault (a short) was in the headlamp wiring/switch then yes that would account for the spike at least (lets hope the DVR2 is still ok - thanks to the fuse). If the wiring and switch check out OK try a different headlamp bulb. (remembering headlamp and tail lamp are on the same circuit). I'd be suspicious of that switch.

BSA500 - I think all the wiring diagrams show the only things on the battery side of the ammeter should be the battery and the horn (like, why show the occasional current spikes of the horn) and it would probably be wise to re-wire to that

[BSA500]

It goes to over charge because the generator is feeding into a fault.
You are reading the output from the generator, not the battery.
Is your light circuit connected to the generator or the battery side of the ammeter?
If connected to the battery side, this will happen.

Trev I think i get what you are saying - if the lights are connected to the battery side of the ammeter then the extra current of the lights (and battery charge current) could show a high reading as the genny/reg tries to power them both (yes?) especially when the revs are up.

and there must still be a fault, or two, to account for the sudden spike. And weird that the DVR2 will allow such a lot of current to flow out of it. however if the fault (a short) was in the headlamp wiring/switch then yes that would account for the spike at least (lets hope the DVR2 is still ok - thanks to the fuse). If the wiring and switch check out OK try a different headlamp bulb. (remembering headlamp and tail lamp are on the same circuit). I'd be suspicious of that switch.

BSA500 - I think all the wiring diagrams show the only things on the battery side of the ammeter should be the battery and the horn (like, why show the occasional current spikes of the horn) and it would probably be wise to re-wire to that

Okay lots to try. Lucky that the mot testers f****d up today and I now have week to fiddle about. Thanks I will work through this.

[duTch]

 No work today, so I'll do some research...Mine is Standardish system though- 6V (- ve earth) & mechanical reg, so obviously a different animal.

 To sum up what it's doing is; lights on- full discharge. Engine running, ammeter shows various charge- up to full (~8A) Lights on; cuts  it back to ~just above 'neutral'...I think, because it varies a bit.

 Battery is ok, shows about ~7.? running and ~6.2 at rest, even when laid up for 7 weeks (analogue V meter 'semi-permanently' mounted).

 I suspect my cut-out needs adjusting, as if I recall I mixed up the value last time (a few months ago)...and I rewired the dipper switch the other day and haven't popped a fuse for a while...

  may or not be of help to you though

[TimK]

 After reading the above posts I'm thinking I should fit an in-line fuze whilst I'm replacing the wiring loom on my 59 GF. What amp fuze should I use (6 V electrics with standard regulator and lights).

Cheers

Tim

[trevinoz]

Good idea.
25 amp or so should do. It will protect against short circuits. And save the wiring from becoming a molten mass.

[mikeb]

i'd use a 15A fuse on a 6v
e3l is 60W =  10amps at 6v (actually  specced at 8.5 amps at 7v) plus some headroom
i'd fuse the horn separately as they suck a bit

[Triton Thrasher]

I'd go for 25 A, rather than 15 A.

20 A is common as a main fuse on 12 V Brit bikes. 6 V systems pass more current.

I like to have a fuse that will only ever blow because of a short circuit in a battery-powered circuit.

[mikeb]

i was basing 15A on what the DVR2 people say for 6v - hasn't blown for me yet.
tho a fair point TT - current may swing around more on an old lucas reg making a higher rating preferable.

[TimK]

Thanks everyone, based on your comments I think I'll start with 20A but carry some 25A just in case.

cheers

Tim

[Bsareg]

I always wire the fuse in the battery earth lead rather than the "live" lead. This still protects all of the circuits and will also blow when I change the battery and accidently touch the live to earth (again), and yes I know the earth terminal should be fitted last but accidents still happen

[mikeb]

wire the fuse in the battery earth lead rather than the "live" lead

it will isolate your battery either way, but not solve other problems, like  battery fuses still won't protect the regulator eg from still driving into a headlamp short (like where this thread probably started. (i've added a second fuse between reg and lights/ammeter, just to be sure and sure again).

for safe battery changes remove the ground first from the battery, not the live.