The BSA A7-A10 Forum

Technical => Lucas, Electrical, Ignition => Topic started by: mikeb on 20.07. 2019 04:16

Title: leaking battery... why?
Post by: mikeb on 20.07. 2019 04:16
i've noticed my 6v 'conventional' lead acid battery (5yrs old) is leaking fluid around the top so now I have a small garden of crystals around the battery holder and tarnished marks on the chrome mudguard. i thought this only happens when batteries boil due to overcharging. but the levels are correct and its charging thru a dvr2 and i haven't noticed any unusually high charge rates (should my ammeter be believed). i should note the battery holder had broken so the battery may have been jiggling around, but i'd guess only a bit.

any other reason batteries have acid coming out the top?
thanks
Title: Re: leaking battery... why?
Post by: duTch on 20.07. 2019 08:16

 What kind of venting does the battery have? Really needs a tube exiting as far back as possible
Title: Re: leaking battery... why?
Post by: mikeb on 20.07. 2019 08:27
The only venting is via the tiny holes in the cell caps. No option for a tube. It's a yuasa b38-6a. Hasn't done this before
Title: Re: leaking battery... why?
Post by: bikerbob on 20.07. 2019 16:08
If you have a multimeter it is easy to check what is coming out of the DVR2. Assuming you are positive  earth you put the positive lead of the multimeter to the battery earth and the negative lead to the white cable coming from the regulator then start up and see what readings you are getting the instructions come with the regulator. I have a cyclon battery fitted to my A7 so no acid  but my A65 has a lead acid battery and it has a small tube for ventilation but I learnt the hard way to make sure that the tube vent does not vent next to anything it did some time ago after first fitting the battery the vent was above the silencer and it did drip one drop of acid onto the silencer marking the chrome, I did polish most of the mark out so you do not notice it.
Title: Re: leaking battery... why?
Post by: morris on 20.07. 2019 19:28
Most batteries are past their best after 5 years of use. If I were  you I would get a new gel battery.
Have a 6v one on the plunger. Maintenance free, no spills and no vent tube to worry about.
Title: Re: leaking battery... why?
Post by: chaterlea25 on 20.07. 2019 20:44
Hi All,
If and when a battery does not readily accept charge so the voltage rises to the cut off value of the regulator
The dynamo and regulator do not know how or why this is happening they just stuff as much current into the battery as they are able to in a bid to raise the voltage
A tired or sluggish battery will absorb the current and gas excessively causing the problem of spillage *problem*

John
Title: Re: leaking battery... why?
Post by: mikeb on 21.07. 2019 02:55
thanks for your comment guys
i'm gong to conclude the battery is past its use-by and hence sucking up the current to create more gas. time to replace it.
i have 2x6v 5Ah cyclons on the b33 and am very happy with them (except for the price), but it appears the 5Ah ones are no longer available in NZ. being a later a10 (1961) i could get  a battery box and one 6v 8Ah cyclon.

Question: how many amp-hours would you want on the a10.  the bike runs all LEDs lights and I'm not planning on an electric start any time soon.  i guess 0 is adequate but a 4 at least desirable. a lot of 6v agm ones are 4 Ah... what is enough?
Title: Re: leaking battery... why?
Post by: BSA_54A10 on 21.07. 2019 04:25
Measure you maximum current draw with lights on high beam & the brake on.
Should be around 0.1 to 0.2 A on an all LED system
Then divide the Amp hours by the amps drawn
So a 0.2A draw will run 25 hours on a 5 Ah battery between charges provided you don't go round playing a tune on your horn.

Since the Wassell regulator destroyed the dynamo on the M20 ( should have known better ) I have been running total loss on the M20
To date have put in about 20 hours riding time on the 5Ah cyclon and it is still running bright.
Title: Re: leaking battery... why?
Post by: duTch on 21.07. 2019 10:02

 
Quote
...........Question: how many amp-hours would you want on the a10.  the bike runs all LEDs lights and I'm not planning on an electric start any time soon.  i guess 0 is adequate but a 4 at least desirable. a lot of 6v agm ones are 4 Ah... what is enough?...

 No matter what the system or current needs, I will suggest as much capacity as the physical battery space will allow