The BSA A7-A10 Forum

Technical => Lucas, Electrical, Ignition => Topic started by: a101960 on 24.02. 2019 13:37

Title: Charging issue
Post by: a101960 on 24.02. 2019 13:37
Woke the bike up from it's winter hibernation only to discover that it is not charging. The battery (batteries are) X2 6v Cyclons wired in series to give 12v. I checked the batteries and discovered that the voltage is down to 10.7v. Now here's the thing I  removed the batteries and connected them up to the two chargers that I have and neither one of the chargers would charge. So, I separated the batteries and one of them took a charge on the 6v setting whereas the other battery registered 4.2v and will not take a charge. That is to say both chargers charge battery 1 whereas both chargers would not work when connected to battery 2. Now what I am wondering is this (before I rip the dynamo out to check it) is it possible that this could be the cause of my no charge problem on the bike? I am using a DVR2 electronic regulator by the way. My guess is that because my of the Cyclons has expired it does not matter what I do the charging circuit is not going to work until I fit new batteries. Would I be correct in assuming this? By the way when I layed the bike up last November everything was working fine.
Title: Re: Charging issue
Post by: beezermacc on 24.02. 2019 15:57
Correct (probably!) If one of the batteries won't take a charge off the charger, then it won't take a charge off the DVR2 / dynamo either. You have two batteries connected in series so technically this is now just one battery, half of which is duff, which renders the whole battery (i.e the two batteries wired together) duff.
Title: Re: Charging issue
Post by: Bsareg on 24.02. 2019 16:32
Some of the modern intelligent chargers won't  charge if the battery is outside certain limits. Try an old style charger to see if will start things moving, ifso, then switch to the modern.
Title: Re: Charging issue
Post by: bsa-bill on 24.02. 2019 16:34
Had three of those batteries at one time (on bike 12 volt the other 6) the plan was I could if needs be swap them around, they are prone not to take a charge if they get to far down, I ended up with one duff, one that would not get over 5 volt and the other lasted quite well, modern chargers have some quirks as well
Title: Re: Charging issue
Post by: RogerSB on 24.02. 2019 19:44
I've always understood that:-
A 12v battery fully charged and while still connected to the charger should read about 14.5 - 14.7v. After being disconnected and settling it should read about 2.1v per cell, so a 6 cell battery should register 12.6v on multimeter.
12v would indicate low charge.
11.8v indicates needs charging.
10.8v  indicates dead battery.
Title: Re: Charging issue update
Post by: a101960 on 27.02. 2019 14:33
Well, it turned out to be the battery that was the cause of the no charging problem. I bought and fitted a new battery and all is well with the exception of this caveat. At 2000 rpm the ammeter is indicating a 4 amp charge rate, and at 3000 rpm about 6 - 7amps. The new battery is a Cyclon 8 ahr battery the old one (A Cyclon) was rated at 5 ahr and the highest I ever saw that go was 4 amps if I blipped the throttle. Voltage measured before start up was 12.3v and after running the engine for a couple of minutes it measured 12.5v. Is this OK? I am hoping after a reasonable run that the charge rate will fall back a bit because it does seem to be on the high side. The regulator as I mentioned the when I posted this topic is a DVR2 and the dynamo is driven by a Manortech belt kit. observations anyone?
Title: Re: Charging issue
Post by: mikeb on 27.02. 2019 19:35
observations anyone?
more some speculations: that charge rate sounds ok to me, yes maybe a bit higher than expected but doesn't the dvr2 limit maximum change rate (I may have imaged that). also you'll have a 10A fuse inline (right?) which will stop any big trouble. I assume your Lucas (or copy) ammeter is not exactly a calibrated instrument so +/- 30% and who knows what the charge actually is. I've seen my ammeter pretty far over when the bike has been sitting for a while but it settles down fairly soon (that's with 2x cyclons on the 12v B33 and wet lead-acid on the 6v A10).
From memory Cylons specify their charge rates in C, and I've never got my head around that specification. You could do the maths. But I'd be 95% sure that after a long ride it will settle down to a more comforting 2-3A
Title: Re: Charging issue
Post by: groily on 28.02. 2019 07:55
Bit more speculation  . . . I wonder what does a meter show for battery voltage, across the terminals, with the engine running at various rpm? It should  start at your 12.5v base or whatever, then rise to about 14 and settle there whatever the revs (or load).
Just wondering whether the thing is regulating properly.

If you run it with the battery disconnected and put a meter on the brown A line from the regulator to earth, what shows? Again, should settle at about 14v when running at 'regulated' rpm. Bit spikey maybe, especially with a digital meter, but should be good enough to show that things aren't heading ever-upwards. It should show much the same when lights are on, but need a few more revs to get there usually.

If the volt meter is like like a tacho, with voltage continuing to rise with revs and no sign of stopping them, then either there's a problem in the regulator or there is a wiring problem, as it would indicate the field input isn't being controlled. I have a friend's very pretty A7 in the shed at the moment, which exhibited similar high charge symptoms, until it stopped charging altogether. The dynamo is still good, but the solid state regulator isn't - I think the thing had effectively allowed F and D to remain connected (which is the correct situation between cut-in revs and when it should start fully regulating). Then it had cried 'enough' and died.

Normally, as mikeb says, you'd see a small steady charge, with blips of more after, say, idling with the lights on for a bit (as the battery gets a boost to compensate for the temporary drain). With a fully-charged battery, half an amp charge would be pretty normal as a cruising reading out on the road.
The risk (if the thing doesn't settle down soon) is that the dynamo could be 'over-served' like happens to some of us now and then down the pub, and the system could get itself a nasty hangover.
Title: Re: Charging issue
Post by: mikeb on 28.02. 2019 08:23
If you run it with the battery disconnected
is it ok to run a DVR2 with no load - ie the battery disconnected? may pay to check first. or put a low value (e.g. 22 ohm) high power (10W) resistor between the DVR2 output and the battery, and measure at the DVR2 end.
personally I'd just add revs and see if the fuse blows (=10Amps). if so you have a problem  *eek* like what groily says
Title: Re: Charging issue
Post by: berger on 28.02. 2019 14:33
I don't know much about anything that's why I am a danger to myself but we must not get confused with say 15 amp blow and the other ones which are continuous and lets say 35amp blow - I made the mistake of using a car fuse which of course blew straight away and I am pretty sure my DVDR thingy regulator packed up because I had a 12volt system with a low amp hour battery which the reg didn't like- of course the auto sparkys amongst us will know the ins and outs of electrickery. no pub for me today . *eek*
Title: Re: Charging issue
Post by: groily on 28.02. 2019 17:36
I think it's not recommended mikeb, but pretty sure it shouldn't harm it (unless Manormike comes in and says 'you stupid boy' that is).
I unknowingly ran for a good few miles in the dark with a busted battery terminal a couple of years back on one bike, so I know the regulator can certainly work without the resistance of the battery in there. Only realised something was wrong when the lights went off when the revs dropped to tickover at a Stop sign! Nothing was damaged, as it's still going fine.

Title: Re: Charging issue
Post by: mikeb on 28.02. 2019 18:01
Good to know it's durable Bill. It may need a load to regulate. So if it does regulate to 14.4 then all is well, but if it doesn't that doesn't mean there is s problem, unless manormike can clarify
Title: Re: Charging issue
Post by: RDfella on 28.02. 2019 18:02
A10 - you say you bought and fitted a new battery. Does that mean a 12v battery, or a new 6v to go in series with the existing 6v? If the latter, you've got some problems in store. When you have two batteries in series (2 x 6 to get 12v, or 2 x 12 for a 24v system) if you put a new one and old one together, pretty soon the system will fail, as the old one requires more charging than the new and so you get half you battery under-charged and half over charged. Also, your new battery is of higher AH than the old one, and therefore not the same as the other half of your 12v system (assuming I've understood you correctly). Better get out and buy a 2nd battery the same as your new one.
Title: Re: Charging issue
Post by: a101960 on 01.03. 2019 08:37
It is a completely new 12v battery. Cyclon 12v 8ah one unit as opposed to the old Cyclons which delivered 12v by connecting 2 6v 5ah modules in series.
Title: Re: Charging issue quick update.
Post by: a101960 on 24.03. 2019 16:11
All the problems I had were due to the DVR2 going bad. It was not regulating for some reason. It was absolutely fine before the winter lay up. As a temporary work round I have fitted an old AO vreg 2 that I had lying about and everything is working fine. The DVR2 popped the 10 amp fuse, no idea what caused the regulator to fail, any way a new DVR2 ordered.
Title: Re: Charging issue
Post by: berger on 24.03. 2019 19:58
I am sure I had a modern solid state dvl2 thingy jig a bit reg fail when I had a low amp hour 12v battery on, can't remember what amp hour maybe something daft like 3, I put a new ddv2 thingy on with a possibly 8 or 10 amp hour , can't remember and no problem.