Author Topic: 12v batteries  (Read 4646 times)

Offline RogerSB

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12v batteries
« on: 13.10. 2017 09:57 »
Hi,


I haven't used my 1960 Golden Flash for a couple of weeks due to our lovely (not) weather! Flicked my lights on earlier this week and . . . eek! Very dim  *sad2* . Our last ride (my wife as pillion) was for about 20 miles on country roads so battery should have had a bit of a charge as we would have been doing up to 50 mph at times - (no lights on). So I'm thinking maybe it's time to start looking for a replacement battery.


Bike has been converted to 12v and uses the following: 12v Varta Powersports 12N7-3B (YB7L-B), 7Ah, CCA: 74A battery. V-Reg II regulator by AO Services, dynamo belt drive conversion. Amp meter shows a charge over about 45 mph.


I was going to settle on a Motobatt MB9U (Absorbed Glass Matt), 11Ah, CCA 140A battery as I've read that it will hold a charge a lot longer than a wet lead acid battery and can withstand vibration better but then read that it needed at least 14v, while my GF's dynamo will only provide half of that . . . so should I think again?


I realise that the high CCA isn't a big factor unless you need it for cranking (my foot does that). Obviously the battery dimensions are an important factor as is good standby capability for the winter months when most of out bikes stand idle for longer than usual here in the UK.


There must be wealth of info out there amongst our A7 and A10 owners on how suitable present day 12v batteries are for our bikes, so any info on your experience with your batteries would be most welcome.


Cheers, Roger.

1960 Golden Flash

Online JulianS

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Re: 12v batteries
« Reply #1 on: 13.10. 2017 10:10 »
My A10 12 volt converted (using a JG regulator) uses a YTX7L-BS agm battery about 6AH.

Fits nicely in the battery holder with wire retaining clip.

Using a 35/35 Osram Night racer bulb (good light and range) and led tail/stop. Charge balances on ammeter at a about 35 mph top gear. I ride with lights on.

Currently using a Lucas badged battery (cheap, 12 months use so far fine no problems),  the previous Yuasa (expensive)  lasted for 7 years before fading away.

Offline duTch

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Re: 12v batteries
« Reply #2 on: 13.10. 2017 10:13 »
 At least the lights come on, so best check the S.O.C (voltage), and clean the terminal connections (if not already done)  and check the avoid level then see what happens.
 I think a lot of people waste a lot of money and batteries unnecessarily.
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline mikeb

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Re: 12v batteries
« Reply #3 on: 13.10. 2017 11:08 »
i don't know the regulator you've got but i thought all 12v batteries need 14.4v to charge. your dynamo will fire that out plus more if you rev it enough. it you've got a slightly higher ratio on the belt drive then i think 45mph is about right to start charging for a 6v dynamo. some belt kits start charging at even lower revs due to even better ratios. if you got the dynamo rewound for 12v then it should start to charge closer to 30mph.

I heard or read  or googled to the contrary -  that motobats don't like vibration and also don't like the cold. tho i wouldn't put money on this. I use 2x 6v cyclons in series in the b33 (12v) as they fit in a rubber battery box.

i wonder if we all over think this stuff. no electric start to worry about and low amperage fittings. just about any battery should do. I'd favour some kind of agm so it won't ever leak.   just don't get a lithium as the charge characteristics are very different and they catch fire when treated badly.
New Zealand
'61 Super Rocket  - '47 B33 -  '21 Triumph Speed Triple RS

Offline a101960

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Re: 12v batteries
« Reply #4 on: 13.10. 2017 14:25 »
Quote
I use 2x 6v cyclons in series in the b33 (12v) as they fit in a rubber battery box.
Me too on my A10. Truly a "a fit and forget" item. I also have the excellent DVR2 electronic regulator and belt drive kit. The cyclon batteries hold their charge well throughout the winter months when the bike is laid up. When out riding I never see the ammeter pointer move from the centre position very much unless I blip the throttle because the cyclons hold their charge so well. The Lucas E3L is well up to the task of keeping the batteries fully charged. I would say this in passing, I personally do not have a very high opinion of V-REG regulator I found that mine when I had one fitted to my bike had a tendency to discharge the battery back through the dynamo when idling. The DVR2 does not do this.
John

Online chaterlea25

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Re: 12v batteries
« Reply #5 on: 13.10. 2017 16:22 »
HI Roger,
Quote
V-Reg II regulator by AO Services,
Quote
Amp meter shows a charge over about 45 mph.

Those regulators are notorious for discharging back into the dynamo at lower revs  *problem* POS *ex* *ex*
The bike should charge the battery and then "switch off" the charge once the battery is fully charged and the lights off

What belt drive conversion is fitted? toothed or vee belt?

A 12 volt conversion should balance a 35W headlamp plus 5W tail at about 30 MPH fitted with a +10% toothed belt
drive dynamo
(At least mine does *smile*)

John

1961 Super Rocket
1963 RGS (ongoing)

Offline RogerSB

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Re: 12v batteries
« Reply #6 on: 13.10. 2017 16:31 »
Many thanks chaps, that's what makes this forum great - always other very willing to help with good and helpful advice.


Julian, if you don't mind me asking, what brand is your AGM battery. I see there are Varta and Yuasa in YTX7L-BS specification.


Wiring is all good as I checked and renewed a lot of the wiring and terminals earlier this year. However, I haven't yet checked the specific gravity of mybattery. What I have done is charged it with my iMax B6 charger and when it was fully charged the reading was 14.7v and I confirmed this with a multimeter. Today (24 hrs later) it's 12.63v, which I know is normal and my 40/38w headlight is shining bright so I'll keep checking with my multimeter. If it continues to drop to 12v or under quickly while just sitting there and my light goes dim I think it's new battery time.


Also Interesting to hear about a V-Reg discharging through the dynamo. Was that a V-Reg or V-Reg II? The V-Reg II is an upgraded version of original V-Reg and I've read that it was designed to act more like the mechanical control box in that after the cut-in speed is reached and the bike slows down again it goes negative (seen on the amp meter as a 2-3 amps discharge and then will flick to zero). Of course in some riding situations this will happen a lot so (as I've read) it shouldn't be cause for concern. I believe all this is controlled by a diode which acts as a one way valve so no current can flow backwards.


My Golden Flash was already converted to 12v when I bought it so I don't know what dynamo belt conversion I've got. I'm going to have a look when I carry out some maintenance on it shortly.







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Offline RogerSB

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Re: 12v batteries
« Reply #7 on: 13.10. 2017 16:36 »
Hi John, thanks for that. It sort of confirms what I've just written about how the V-Reg II works. I don't profess to know exactly how it works - it's just what I've read about it.

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Offline RogerSB

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Re: 12v batteries
« Reply #8 on: 13.10. 2017 16:45 »
Attached is section of the article mentioned. Hope you can read it ok.

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Online JulianS

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Re: 12v batteries
« Reply #9 on: 13.10. 2017 18:11 »
My battery says Lucas on the case but goodness knows who made it. Cost me about £20 including post past year.

Online chaterlea25

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Re: 12v batteries
« Reply #10 on: 13.10. 2017 21:03 »
Hi Roger,
That article says the same thing as I wrote earlier
A further problem with them is if the battery voltage drops below a certain value they will not self excite and charge the battery. This causes lots of problems with  battery ignition vintage bikes
Test you existing battery by turning on the headlight and see if it will keep the voltage up for at least 30 minutes

There are other regulators on the market that do not have this issue, most owners here seem to favour the DVR2
http://dynamoregulators.com/voltage-regulators.php

John
1961 Super Rocket
1963 RGS (ongoing)

Offline RogerSB

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Re: 12v batteries
« Reply #11 on: 14.10. 2017 10:29 »
Thank you Julian and John for your latest.


Well, checked my battery this morning and it was reading 12.64v (12.63v yesterday) so that's a good sign as that's what it should be after just sitting there for a couple of days after its initial settling down period. Early days so I'll keep checking for a couple of days more and if it's stays there I'll check again after doing 20 or 30 miles (without lights on) to see if it maintains a charge.


Thinking about my last ride, it was 20 miles on narrow country roads over Dartmoor. The roads were damp and in some places still very wet after rain during the night with lots of dead leaves and so lots of gentle breaking and stopping at junctions. A 30 mile ride previous to that was also on country roads so similar riding but with dry roads. If what John has pointed out is happening then that would explain a flat battery as riding slowly and with lots of braking on the narrow roads my stop light would likely have been on half the time . . . and its 21/5W. Once off the narrow moor roads and on the main roads we were, of course, able to ride at a speed for the dynamo to cut-in occasionally but was it enough to put a decent charge back in the battery . . . I suspect not. So I won't rush into replacing my battery just yet but may have to replace my regulator for a DCR2 instead. If it stops raining a good ride should provide an answer.

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Offline RogerSB

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Re: 12v batteries
« Reply #12 on: 14.10. 2017 11:25 »
Just found this: DVR2 vs V-RegII.

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Online JulianS

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Re: 12v batteries
« Reply #13 on: 14.10. 2017 11:39 »
I would consider changing your tail/stop bulb for an LED replacement. Current consumption very much less.

Offline RogerSB

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Re: 12v batteries
« Reply #14 on: 14.10. 2017 12:01 »
Yes, that's now on my list Julian. I'm thinking it must be a big factor in my battery draining, as well as the way my regulator works. Always been aware of headlights draining the battery at slow speeds but as I don't often ride at night I rarely need my headlight on but I never really considered how riding on narrow country roads impacted on how often and how much my stop light would be on by having to constantly slow and brake for oncoming traffic, bends in road, etc.. . . until recently!

1960 Golden Flash