classic motorcycle forum

Motorcycle Discussions => British Bikes => Topic started by: JohnnyT on January 22, 2019, 12:48:07 PM

Title: Battery drain
Post by: JohnnyT on January 22, 2019, 12:48:07 PM

Bought a new 6vbattery for my Triumph Tigress scooter.I only have speedo light fitted to test things and it worked fine.Next day the battery was flat.Only other things connected are brake switch and rectifier/switches.Any tips on where to start to find short?

Title: Re: Battery drain
Post by: Rex on January 22, 2019, 01:13:47 PM

The usual way is to connect a DVM in series with the battery lead and sequentially connect/disconnect things to see where the fault lies.

Title: Re: Battery drain
Post by: iansoady on January 22, 2019, 01:48:05 PM

Set on the 10 amp range, at least initially.

The most likely source of the problem would be the rectifier. Is it the original plate type?

Title: Re: Battery drain
Post by: JohnnyT on January 22, 2019, 03:15:12 PM

Yes it is.I have a new one so I will try that.Will try the meter as well.

Title: Re: Battery drain
Post by: 33d6 on January 22, 2019, 11:30:40 PM

Those selenium plate rectifiers die of old age even when not used. If yours is still working properly it would be the only one on the planet.  It's time for a new solid state jobbie. Modern electronics allow us to upgrade old systems and make much better use of  the lower capacity available from original charging layouts. Your scooter will be much better for it.

Title: Re: Battery drain
Post by: JohnnyT on January 23, 2019, 05:00:27 PM

One of these ? Scooter has positive earth.
https://www.ebay.co.uk/i/254053354686? (https://www.ebay.co.uk/i/254053354686?)

Title: Re: Battery drain
Post by: chaterlea25 on January 23, 2019, 08:09:27 PM

Hi Johnny,
No, that one is for a dynamo equipped motorcycle
One of these will replace your existing plate rectifier, but you are still dependent on the old switching of the alternator coils for crude regulation
https://www.ebay.co.uk/itm/Solid-state-rectifier-Classic-motorcycle-12-or-6-volt-Triumph-BSA-X2/223306091454?hash=item33fe148bbe:g:egYAAOSwKtVWyMgv:rk:2:pf:0

Here is an ebay link to 6v rectifier regulator units for alternators
These are a better option than the switched output setup originally fitted

https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=6+volt+rectifier+regulator&_sacat=0

John

Title: Re: Battery drain
Post by: JohnnyT on January 27, 2019, 10:31:32 AM

33d6 good shout swapped the rectifier and battery syill good.