The BSA A7-A10 Forum

Technical => Lucas, Electrical, Ignition => Topic started by: BSA500 on 31.08. 2012 08:39

Title: A7 charging issue?
Post by: BSA500 on 31.08. 2012 08:39
Hi,
The question mark is there for a reason I shall explain. I have a A7 in daily use and that includes winter(30 miles a day) so lights are quite important. What I have at the moment is a dynamo running at 12 volts pos earth with a 12 amp hr battery and a vreg 2 regulator and a belt drive. The dynamo was rebuilt/serviced last year by beezermac. Now I have been running all summer so I would expect the battery to be charged,not so!!. With the lights off the ammeter just hovers above the 0 in charge from just above tickover. Lights on the ammeter shows discharge -4 and quickly rises to just above 0 from jsut above tickover and stays there. No matter how many revs it goes no higher and if you stop for lights and tickover the lights dim,nice and bright while running,but dim at stops. It seems either battery will not take the charge or the reg will not put out anymore. Any suggestions as where to start??
Andy
Title: Re: A7 charging issue?
Post by: iansoady on 31.08. 2012 10:56
That sounds about right if the battery is fully charged. The voltage regulator stops excess charge so unless the battery is flat(tish) there shouldn't be too much going into it. Remember the lights etc are fed from the dynamo side of the ammeter.

The only thing I would be thoughtful about is the lights dimming, although I would expect this to some extent as when the dynamo is charging the voltage in the system is getting on for 14 volts; when at idle it'll be more like 12.
Title: Re: A7 charging issue?
Post by: BSA500 on 31.08. 2012 12:03
Surely the battery should have the capacity when fully charged to keep the lights bright for a minute or two at the lights. So does that suggest the battery is unable to except and hold charge?
Title: Re: A7 charging issue?
Post by: Dynamo Regulators Mike on 31.08. 2012 15:53
Hello Andy

Don't like to simply knock the competition but the VReg2 can struggle to maintain charge at 12 V. It takes a lot of revs to get the output up to the 14 V or a little more, which is required to fully charge the battery. See http://www.dynamoregulators.com/about.php for more on this subject.

I suggest you monitor your battery voltage and check for any such shortfall in charging voltage.

The VReg2 has been around a long time unchanged (except for its case). With no load there is a 2 A or so discharge at low speeds where the battery is supplying the field in vain. This is a design shortfall. I am constantly surprised how those things keep selling, but you pays your money and you takes your choice. Caveat emptor.

Mike
Title: Re: A7 charging issue?
Post by: BSA500 on 31.08. 2012 17:41
I get the feeling you may be right. I don't really suspect the dynamo as when you switch on the lights it quickly balances out and beezermacc fixed it last year *smile*. The belt drive helps as it is the extra wide and spins up the dynamo by 20%. I have removed the battery which is a year old sealed type 12 amp hour and the reading is 12.08 volts not alot considering its summer. I will check the dynamo f&d together etc. I checked with the battery in place and the highest reading was 12.78 volts so hopefully I can rule out one or the other.
Title: Re: A7 charging issue?
Post by: BSA500 on 31.08. 2012 19:46
Update....
Connected the f&d together and got a healthy output easy 16 volts plus so looks like a new reg,prob the DVR to go with the belt drive from them. Problem is I need to charge up the battery but the only charger I have is the car one which pumps out 6 amps.My bike Oxford charger blew up. I should avoid electrics *conf*
Title: Re: A7 charging issue?
Post by: stu.andrews on 31.08. 2012 20:59
A cheap reliable 2/6/12 volt charger is often available from both Aldi & Lidl. I've had one for several years. They can be left attached as the charging current is only 0.6 amp.
Title: Re: A7 charging issue?
Post by: duTch on 31.08. 2012 22:30
Heya Andy,
                 I couldn't see you mention the headlight Wattage, which could be loading up the system??

 Cheers, duTch
Title: Re: A7 charging issue?
Post by: Triton Thrasher on 01.09. 2012 01:59
Surely the battery should have the capacity when fully charged to keep the lights bright for a minute or two at the lights. So does that suggest the battery is unable to except and hold charge?

Usually, you cannot keep headlight on in traffic with a 6V dynamo regulated to 12V. Many people use a pilot light with 10W halogen bulb or somesuch, for town work.

The speeded up belt drive and DVR2 may help, or even fix the situation. I haven't used them.

Manormike is right- the waste of 24W (2A) at idle is a daft feature of many electronic dynamo regulators.
Title: Re: A7 charging issue?
Post by: BSA500 on 01.09. 2012 10:21
I am ordering a new charger today as we don't have a decent Lidl and no Aldi within 50 miles there's nothing down south *smile*. The headlight wattage is 55/60 and I have an led rear lamp, but that's not the issue as I have run the bike all summer with no lights and still the battery is no where near charged. The vreg coupled with the belt drive copes to a point as I said it quickly balances when lights are on from just above tickover but no more extra to top up the battery.
Title: Re: A7 charging issue?
Post by: saltbox Alf on 01.09. 2012 12:25
Jut as an after thought , I run a DVR2 reg but still have chain drive to dyno, but i had a similar problem re charge rate. After sorting all the bullet conectors to see if they were making well, all seemed fine, still the problem! just as a rueling out I put another ammeter in place, spare one kicking around the w/shop and lo and behold proper charging rate and battery keeping charged, I think the old ammmeter had gone high resistance in it guts somewhere *dunno* However I am pleased with the DVR2, does what it say's on the box.
Title: Re: A7 charging issue?
Post by: warmshed on 02.09. 2012 08:33
You need to get a meter and measure the voltage of the battery and also when engine is running, or it will just be guesswork. I have a DVR2 and without lights,  it gets up to 14.6 volts at around 2000+ RPM.
Don't forget that running a 55 watt headlamp with a pilot bulb (noted the LED rear lamp) you leave very little output to charge the battery and the dynamo will have problems maintaining the correct voltage to the battery or the headlamp. 
Once charged a good 5AH battery should in theory,  have sufficient capacity to run a headlamp for an hour, in reality you can expect a good 30 mins, so the stops at the traffic lights should not present a problem.

Batteries as they age or have been abused, can give a good terminal voltage (but normally slightly lower) but will have seriously reduced capacity, that's why the best way to test a battery is with a load tester.
Title: Re: A7 charging issue?
Post by: Triton Thrasher on 02.09. 2012 09:23
I'd try a 35W halogen bulb and switch to pilot lamp wherever there  are street lights.

Ammeters are rather notorious for failing. You don't really need one. If the lights brighten when you rev off idle, that's all the test you need on the charge system when you're on the road.
Title: Re: A7 charging issue?
Post by: BSA500 on 02.09. 2012 10:46
quote from a previous reply of mine

 "I checked with the battery in place and the highest reading was 12.78 volts so hopefully I can rule out one or the other."

and another

"Connected the f&d together and got a healthy output easy 16 volts plus"

So it looks like the reg is playing silly buggers. Yes the lights will brighten off idle but it stops short of putting out enough to charge the battery so when I stop for any reason they dim straight away. I also have a 12 ah battery on board so if charged correctly this should not be an issue. My ride to work each day is mainly A roads rarely dipping below 45 mph. And it should have a healthy charge right now as I don't ride with lights on in summer.

Title: Re: A7 charging issue?
Post by: Triton Thrasher on 02.09. 2012 11:33
Lights going very dim at idle can be flat battery, which can be a bad battery which will not charge, or can be a battery which is isolated from the charge circuit or has high resistance between it and the circuit, such as at a bad connection.

I had a Boyer reg which regulated to too low a voltage. I phoned them and they didn't believe me, which wasn't much help.
Title: Re: A7 charging issue?
Post by: BSA500 on 02.09. 2012 11:47
I will find find out if the battery is rubbish when the charger arrives. But the measured voltage across the terminal does suggest low output from the reg. I know how to suffer I once had a JG reg that would melt the solder on the dynamo during heavy use :!
Title: Re: A7 charging issue?
Post by: BSA500 on 07.09. 2012 19:41
Right charged the battery and the reg/ammeter shows no change. ie it is reading/doing the same as when the battery was flat. The charger proved the battery is capable of taking and holding a charge so it looks like a DVR reg is the next option at least there will be 2 amps extra flowing to the battery.
Title: Re: A7 charging issue?
Post by: warmshed on 07.09. 2012 22:19
As you have used a meter why have you not measured the voltage with the engine running????
Title: Re: A7 charging issue?
Post by: BSA500 on 08.09. 2012 09:55
Yep i did around the 12.8 volt mark. Which is the same voltage as when the battery is near flat.
Title: Re: A7 charging issue?
Post by: duTch on 08.09. 2012 10:33


Yeah-but,yeah-but, just because you have 12v are you still putting out same amps(10), = 120w..?
I got the notion that it's still a 60 watt output whether it's 6 or 12 volts? ie 12v = 5amps..?
 that means that a 55w headlight at idle would surely dim the light?
 As an 'aside' (that's a Shakespeare moment), I had a situation, many years ago, sitting at the lights and a 'well meaning' officer came over and informed me I had no lights, but after  a little rev, he 'went away'....

 I may be wrong about the wattage/output??
 cheers, duTch
Title: Re: A7 charging issue?
Post by: BSA500 on 08.09. 2012 11:03
I understand where you are coming from. My issues is that riding around for 2-3 months(150 miles a week) without using the lights I would expect the battery to be fully charged and not near flat. Also when finding out the state of the battery I was surprised to see the reg does not seem to reconise this and supply the battery with enough 'amps' to compensate ie the needle of the amp meter barely rises above the 0(it is a new meter) and when first installed was acting as it should. The proof is that what ever the state of the battery the reg will not push out enough to completely match the demands. BTW the rear lamp is a LED which uses nothing in electrical terms. All connections are clean no rubbing wires etc.
Title: Re: A7 charging issue?
Post by: bsa-bill on 08.09. 2012 11:16
Hi dutch - you didn't mention Ohms, you need to
Don't know how many of us 12 volters ever get around to re wiring our bikes but I suspect we should (it's on my to do list).
it's a simple formula for the relationship of volts, watts, amps but I can never remember it, probably because it so simple; Pythagarus on the other hand I can get my head around no trouble (thank you little Mr Williams my old maths teacher).

Yes it sounds like your getting something for nothing but it does work that way
Title: Re: A7 charging issue?
Post by: Triton Thrasher on 08.09. 2012 11:23
Yep i did around the 12.8 volt mark. Which is the same voltage as when the battery is near flat.

I used a Boyer Power Box dynamo 12V regulator, which regulated the voltage to too low a figure, like that. If the unregulated dynamo, with D and F joined, can light a headlamp bulb and exceed 15V, the regulated voltage should exceed 14V when you rev it up.

A charging system regulated to 12.8V is just about useless.
Title: Re: A7 charging issue?
Post by: BSA500 on 08.09. 2012 12:09
My point exactly. I had issues with my car alternator and when I replaced it I was able to see a healthy 14.5 volts across the battery I would hope to see something near that.
Title: Re: A7 charging issue?
Post by: BSA500 on 17.09. 2012 22:21
Guess what the v reg decided to work again today. The ammeter went up to about 3/4 amps at full chat. Still going to get a DVR2 seeing as I cannot trust the vreg with winter coming up. I have not touched anything else on the bike.
Title: Re: A7 charging issue?
Post by: BSA500 on 18.09. 2012 08:25
Scrub that last post regulator has resumed the norm for it ie not enough.
Title: Re: A7 charging issue?
Post by: duTch on 18.09. 2012 09:40

 Hi Bill back,
  Not totally sure what you mean, maybe the one you're thinking of is E=IR, not to be confused with E=MC°˚(squared), which is the formula for putting bubbles°˚°˚ in beer,(Yahoo Serious)
   
     I had figuers but realised they didn't add up will get back to you on that
 cheers

    500, sounds like the dvr2 is on your list
Title: Re: A7 charging issue?
Post by: bsa-bill on 18.09. 2012 10:16
Quote
E=MC°˚(squared)

At last a formula that explains why we're all riding old bikes, now to find a garage with  petrol pumps  from the same time continuum 
Title: Re: A7 charging issue?
Post by: BSA500 on 08.10. 2012 08:39
Dvr on and no change looks like the battery. I say no change the ammeter does not dip 1-2 amps on start up as it was with the vreg and from just above tickover with all lights on, stays in the positive but only 1 amp max. Seems the battery is resisting charge?? as after 5 miles with the bike stopped at the traffic lights they dim to that yellow dimness-makes sense?. Nothing I've missed is there can the ammeter influence the charge rate? or does it just 'read' what is going on???. When running along the lights are nice and bright.
Title: Re: A7 charging issue?
Post by: BSA500 on 09.10. 2012 09:24
Just checked the charge across the battery terminals and getting 14+ volts. Spoke/email Mike at Dynamo regulaters and he agreed the battery is stuffed prob too many charge/discharge cycles. Also when I tested using the vreg it was only putting 12.8 volts into the battery so look like they both decicded to die which begs the question who killed who *conf*
Title: Re: A7 charging issue?
Post by: morris on 09.10. 2012 12:10

Battery's can act strange sometimes.
I remember a couple of years ago, my car wouldn't start again if I stopped the engine for just a couple of minutes and left the headlights on.
I replaced the battery to no avail, so I suspected the alternator not doing his job. I installed a new one, but I still had the same problem.
In the end it was the battery, which showed 14V, but if I hooked up a bulb, the voltage dropped in seconds.
I changed it for another one, problem solved.
Just checked the charge across the battery terminals and getting 14+ volts. Spoke/email Mike at Dynamo regulaters and he agreed the battery is stuffed prob too many charge/discharge cycles. Also when I tested using the vreg it was only putting 12.8 volts into the battery so look like they both decicded to die which begs the question who killed who *conf*
When reading your last reply though, it came to me that it's perfectly possible that the alternator in my car killed the battery.
I remember changing the battery first because of the same reason, then the alternator, and then had to swap the battery again for a new one
Title: Re: A7 charging issue?
Post by: BSA500 on 30.10. 2012 12:43
Well two weeks in with the DVR2 and new battery and alls well. Battery holds a healthy charge and the DVR makes sure it gets it. Just my luck with all things I do I ordered a new battery and the first one came with a dead cell but they  changed it without any issues.
Title: Re: A7 charging issue?
Post by: duTch on 31.10. 2012 09:11

 Good luck, hope it hangs in well for you cheers, duTch