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Thread: 1981 R80G/S electrical limitations

  1. #1
    Day Dreaming ... happy wanderer's Avatar
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    1981 R80G/S electrical limitations

    I have purchased some Oxford heated grips for my R80G/S and have some concerns about wattage. The alternator only puts out 280 watts on the stock unit. Upgrades are out there but pricey. If it was cold enough to turn on heated grips chances are I'd probably want to use my BMW heated vest too. The grips can draw up to 4A max and I am really not sure what the vest pulls but I would guess about 2A or so. No idea what the overall power consumption of the stock bike is.

    Has anyone had this combo on their G/S?
    Did the battery survive or does the voltage slowly drop?

    I do have a Euro model and the ability to shut the headlight off but in Canada daytime running lights are the law so that is best avoided.
    MJM - BeeCeeBeemers Motorcycle Club Vancouver B.C.
    '81 R80G/S, '82 R100RS, '00 R1100RT

  2. #2
    Cal
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    Watch your tachometer and shut your grips and vest when your rev is below 3.5k

    Cal

  3. #3
    Registered User lkchris's Avatar
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    I've run OE BMW grips with my Gerbings with no problem. Of course I have a headlight switch.
    Kent Christensen
    21482
    '12 R1200RT, '02 R1100S, '84 R80G/S

  4. #4
    Day Dreaming ... happy wanderer's Avatar
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    Quote Originally Posted by lkchris View Post
    I've run OE BMW grips with my Gerbings with no problem. Of course I have a headlight switch.
    Good to know. I've got a tach and recently put a clock on the bike but now thinking I should have gone for a voltmeter instead.
    MJM - BeeCeeBeemers Motorcycle Club Vancouver B.C.
    '81 R80G/S, '82 R100RS, '00 R1100RT

  5. #5
    rabid reader dbrick's Avatar
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    We had two R65s with the same 280w alternator the G/S wears: mine: a 1983 model ridden 1984-1988; hers a 1981 model ridden 1996-1999. Both bikes had always-on headlights.

    Our experience was the same as Cal's and Kent's. Keep the revs up and the battery will stay charged with both the grips and the heated vest. In town where revs are often lower, turn off the grips or the heated liner. In-town riding in the winter would make me use a Battery Tender.
    David Brick
    Santa Cruz CA
    2007 R1200R

  6. #6
    Registered User richardak's Avatar
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    I have the same 280 watt charging system and I run the heated grips with heated liner and gloves and like others have said, when I slow down, I start turning things off. I use the small Datel voltmeter to monitor the battery voltage.

    According to the Gerbing pamphlet, the liner and gloves draws about 9 amps though not continuously. And while cruising down the road, the stock alternator keeps up just fine.
    1983 R100RT hacked w/Cozy Rocket My blog
    Airhead #10576

  7. #7
    Registered User m_stock10506's Avatar
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    Quote Originally Posted by Happy Wanderer View Post
    I have purchased some Oxford heated grips for my R80G/S and have some concerns about wattage. ..... No idea what the overall power consumption of the stock bike is.
    ......
    "Typical electrical usage in the STOCK airhead:
    Headlight 55 or 60 watts; ignition 40 watts; miscl small lamps, etc about 15 watts; charging after battery fully charged...about 10 watts."


    The above was taken from Snowbum's technical articles web page, article 14A. De-mystifying & Troubleshooting BMW Airhead Boxer Motorcycle Electric systems. rev. 01/16/2013.
    http://bmwmotorcycletech.info/techni...icles-list.htm
    You should have about 100 watts to work with provided you are running at typical Airhead RPMs and not sitting at idle.
    Last edited by m_stock10506; 02-13-2013 at 08:33 PM. Reason: Added Snowbum's website URL
    Michael Stock, Trinity, NC
    R1100RT, R100, R60/6

  8. #8
    Registered User beemerguru's Avatar
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    That is fine if your system is in good shape! Resistance from corroded connections, worn brushes, etc, could knock your recharge rate as low at 12.1 or so..barely enough to stabilize the battery charge. Add some type of voltmeter just to be sure.

    I do know that high beam, heated grips, and Gerbing jacket on a stock system will run the battery down to around 10v over time.
    Greg Hutchinson
    R80G/S (4) 633CSi with 450K mile
    '68 R60/2 '88 K100RS Special Edition
    http://gregsgssite.shutterfly.com/

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