BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: Matt Brighton on 14 May, 2020, 16:55

Title: Mystery battery drain ?
Post by: Matt Brighton on 14 May, 2020, 16:55
Hi

Noticed my stop lamp wasn't working and found the battery to be dead flat a few days ago.

I put the battery on charge (6v) overnight and all seemed well upon reconnection  but following night it emptied itself again

After 2nd recharging I noticed the ammeter drops to - 4a upon reconnecting the battery .......despite nothing being switched on ?

The bike had the dynamo belt drive conversion and solid state regulator.

Any advice on where and what  to start checking welcome

Best

matt - brighton 
Title: Re: Mystery battery drain ?
Post by: LightningAndStarfire on 14 May, 2020, 17:29
Not sure, but I think when the oem regulator fails in a certain way the battery can discharge through the dynamo. If so, perhaps the solid state regulator can fail in a similar way. Do you have an ignition switch that cuts off the battery from the dynamo when turnédatum off?
Title: Re: Mystery battery drain ?
Post by: idie on 14 May, 2020, 18:06
It sounds as if the switching diode in the regulator is not working.  My Velo has a regulator that does this. I pull the lead off the battery when I stop and it drops out. The diode that is. I then put the lead back on I have been doing this for over a year. To mean to buy a new one.
Title: Re: Mystery battery drain ?
Post by: Matt Brighton on 14 May, 2020, 18:31
Thanks both

No ignition switch or key on my bike.

I could get a new battery to eliminate that,  and take it from there -

Whilst attaching/unattaching the battery it did once not show a drain so perhaps it is the switching diode -

I now just need to know what it is... where  to find it - what it looks like - where to get another  - and how to replace it ?

Thats again for advice and help - its much appreciated

Matt
Title: Re: Mystery battery drain ?
Post by: Matt Brighton on 14 May, 2020, 19:08
UPDATE

I just had another look..... and found its got a DVR2 regulator fitted in the tool box.

It feels warm to the touch with the battery connected...... so I am guessing somethings amiss in the "box o tricks".

Are these things testable /  repairable or do I just fit another ?

I could give them  call and see if they wouldn't mind taking a look at it - don't think its that old

Best

Matt

Title: Re: Mystery battery drain ?
Post by: idie on 14 May, 2020, 21:53
Interesting that you have the same problem as my Velocette. It is a DVR2 as well. When you speak to Mike tell him that you know of another with the same problem.
Title: Re: Mystery battery drain ?
Post by: Matt Brighton on 14 May, 2020, 23:46
Ok sure

I will give them a call and  let you know how I get on.

Thanks

Matt
Title: Re: Mystery battery drain ?
Post by: Matt Brighton on 15 May, 2020, 14:54
update

i sent Mike from Dynamo Regulators  an e mail asking if they would test it - on their website theres a £10 charge for test .... but thats fine if it eliminates the rectifier  .....or identifies it as having gone bang !

Meanwhile - I discovered that by disconnecting the yellow wire to Dynamo ......the amp draw when battery is connected  is stopped. ????

Have left the bike in bits now, until I can get the rectifier checked out by Dynamo Regulators.

Thanks again for replies and advice

Matt

Title: Re: Mystery battery drain ?
Post by: Matt Brighton on 15 May, 2020, 17:38
Mike Hutchings from Dynamo Regulators Ltd replied same day to say send it in to him for testing

He said in theory it could be the regulators cut out diode having broken down, but this would be rare and and usually caused by a wiring fault or connecting the battery in reverse.

Ill whip it off, send it in... and report back on the outcome.

Matt.
Title: Re: Mystery battery drain ?
Post by: EDDIE SIMPSON on 15 May, 2020, 21:42
i ve had similar experience with my trusty a10. some mornings battery dead and first to blame is the cursed dvr2 with those confounded chinese diodes. went down the regulator route but all the time it was that original leaky headlamp switch which needed overhaul. i always use a keyswitch now to isolate the battery when parked up. another cheap chinese addition , but you need to remember to turn it on every time you fire up.
Title: Re: Mystery battery drain ?
Post by: Matt Brighton on 15 May, 2020, 21:47
Thanks Eddie

Its off the bike now and in an envelope, so I will still go ahead and post it to Dynamo Regulators  and get it tested

if it proves to be ok then Ill take a look at the headlamp switch as you suggested

Thanks

Matt
Title: Re: Mystery battery drain ? SOLVED DVR2 Solid State Regulator
Post by: Matt Brighton on 22 May, 2020, 12:51

Turns out... t was the cut out diode that had failed -  and mike called me to confirm after he tested it today.

Mike said its unusual and usually result of a wiring fault or connecting it wrong way round.

The unit is nearly 10 years old.... (and connecting it wrong way round wouldn't be the most stupid thing I have ever done  - if indeed that was what bade the diode fail) .

A New unit is on its way to me.... £51 posted so Im happy to have found the problem with all your help - so thanks to all who replied and gave advice

Matt
Title: Re: Mystery battery drain ?
Post by: idie on 22 May, 2020, 14:25
Thanks for the message couldn't work out how to reply. Glad it's all sorted. More peace of mind.