monitoring an airhead charging system

Discussion in 'Airheads' started by RocketMan, Jan 10, 2013.

  1. RocketMan

    RocketMan Out Rocketing

    Joined:
    Nov 28, 2004
    Oddometer:
    912
    Location:
    Woodbridge VA
    I have a 1975 R90/6 that I recently picked up and was wondering what is the best way of monitoring the changring system since I run heated gear in the winter. Would a volt meter or ammeter be the better method of monitoring the charge-discharge state of the charging system to help prevent the battery running down due to excessive draw when I crank up the heated gear? Its not so much a problem when I can keep the rev's above 4K, but if stuck in a lot of stop and go the charging system is probably falling shy of the draw, and having a gauge indicating dis-change to remind me to say, turn off the pants or otherwise reduce the draw when I'm not able to keep the rev's up at a more constant rate.

    While I do plan of upgrading the charging system, that probably won't happen this winter so I need a way to monitor the current draw.

    Any thoughts?

    Thanks

    RM
    #1
  2. manic mechanic

    manic mechanic Been here awhile

    Joined:
    Aug 31, 2011
    Oddometer:
    163
    Location:
    up nort' somewheres
    I've got a voltmeter on my /6. I consider that a better indicator of system status.
    #2
  3. disston

    disston ShadeTreeExpert

    Joined:
    Mar 22, 2011
    Oddometer:
    12,093
    Location:
    Silver Spring, Md
    I think a Volt meter will help. I've put a couple on vehicles over the years. If tied to the battery you get a more accurate reading but tieing in someplace else works also you just have a little more resistance and are used to a little lower reading. The actual number of Volts is not the issue. I think tieing into the starter terminal with the big red wire from the battery would be a good place. The R90S has the Volt meter tied to one of the fuses in the headlight. We know the system works and can see what Voltage it generates under different circumstances. Then when the Voltage falls below norm you will notice.

    Amp meters are more complicated. I've had a few problems over the years with older vehicles that had Amp meters that had wiring problems and I just stay away from them because of my experiences.

    The problem on a motorcycle is finding meters that are properly dampened for the high vibration environment. I don't have any specific recommendations but you might notice that some of the better, higher priced, stuff mentions this issue.

    Don't forget to know how you will mount this meter. There was a BMW mounting system with meters in pods attached to the front forks. This works rather well but can be pricey.
    #3
  4. Bill Harris

    Bill Harris Confirmed Curmudgeon

    Joined:
    Sep 20, 2008
    Oddometer:
    9,720
    Location:
    backwoods Alabama
    #4
  5. Prmurat

    Prmurat Long timer

    Joined:
    Oct 28, 2011
    Oddometer:
    1,398
    Location:
    San Francisco, CA
    #5
  6. RocketMan

    RocketMan Out Rocketing

    Joined:
    Nov 28, 2004
    Oddometer:
    912
    Location:
    Woodbridge VA
    I like that, solves the problem of lighting it at night and since it seems that voltage meters have winning votes may just go for this one. Easier to wire in than an ammeter would be since I don't have to pull the front cover and run extra wires in there.

    I'm thinking of getting this as well
    [​IMG]

    the scout fairing I have on the bike has a lip around the top behind the shield that is just at the right angle for viewing anything attached to it.

    So here's a few pics of the bike its going on, as you can see it also has some older style PIA running lights mounted (came with the bike) so wattage useage is a consern esp. when running heated gear! the lights are rigged to come on with the high beam or high beam flasher.

    after I added the scout fairing
    [​IMG]

    before the fairing and also before I swapped out the dual-disk setup from my old r100 that died in a head-on collision a few months ago.

    [​IMG]

    Yeah, I know the seat is a tad short since it came off my R100 which was a /7 with the longer tank. Minor issue for me really, when I find the right seat, I'll swap it out but I like the Corbin over the stock seat.
    Thanks for the input.

    RM
    #6
  7. Bill Harris

    Bill Harris Confirmed Curmudgeon

    Joined:
    Sep 20, 2008
    Oddometer:
    9,720
    Location:
    backwoods Alabama
    It's got an auto-dimming feature too. The display is bright in sunlight and dims at night (or shade). As I said, easy to read and interpret-- if you see Two Green lights, it's optimum. One Green is OK, No Green (all Yellow), start checking. If you lose all Yellow and have only Red left when starting, you may need a battery or starter check. And if the voltage gets way over or under, the whole display blinks.

    --Bill
    #7