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Shorai batteries

Discussion in 'Norton Motorcycles (Modern)' started by Fast Eddie, Dec 15, 2017.

  1. Fast Eddie

    Fast Eddie VIP MEMBER

    Oct 4, 2013
    It’s a big high comp motor with no decrompression facility, and none of us want big heavy car batteries on there.

    I guess there’s only so much the laws of physics can provide !
  2. worntorn


    Dec 22, 2006
    With a PB equivalent 18ah Shorai (LFX18) there is 6ah of actual storage in the battery .
    This is listed on the Shorai site but it's kind of in the fine print.
    With a 12 ah lead acid you have 12 ah of storage.
    So the Shorai will crank like an 18 ah lead acid battery but only for a short time.
    It's got to get the job done fairly quickly or it is spent. They have a high flow rate (this is the 18ah equivalent part) so they can provide great power, but there's not much of it!
    The lead acid battery you have now ( I'm assuming it's something like a 12ah) will grind away much longer.
    I found out about the tiny storage capacity of my 18ah rated LiFe battery when I was about 300 miles from home and charging stopped on my MK3 Commando. The charging had stopped long before that, but this is when the bike stopped.
    Roadside, I installed a spare, fully charged 18ah pb /eq LiFe battery thinking it would run all day. About 50 or 60 miles down the road the bike shut down again, low voltage.
    Fortunately I was at a summit and was able to coast about 5 miles down into a small town.
    Bought a battery charger, charged the lead acid battery overnight and made it home dead loss the next day, 200 miles on one charge.

    Last edited: Apr 5, 2019
    MxMartin and Welshrugby like this.
  3. MxMartin


    Nov 13, 2017
    My Shorai charger was telling porky pies again, wouldn't charge even though it has been on store for a day or two. It refused to charge last time I used it. I unplugged all the multi-pin sockets, plugged them in and out for half dozen times, now it is happy to charge :) Those tiny little pins must oxidise up over time so shall treat the plugs with a bit of silicon grease.
  4. Voodooo

    Voodooo VIP MEMBER

    Aug 10, 2016
    I keep my bikes in a heated /ac garage.
    I also keep both bikes on a shorai Charger all the time.
    Everytime I go to start my bikes after a day or more of sitting, they always struggle to crank. Most often, the starter solenoid clicks at first attempt.
    So I turn the key on, select voltage on gauge display, and wait until I show at least 12.5 + volts. This usually takes about 10 seconds.
    Then I crank it over and it starts right up.

    Anyone else notice this with Shorai batteries?

    I have a Anti-gravity battery for my track car.
    5.2L 12.5:1 compression, V8 and never have the same problem as the Shorai battery. I may try an Antigravity battery in one of my bikes and see.
    MxMartin likes this.
  5. MxMartin


    Nov 13, 2017
    I think this is why those of us that had/have a high residual current draw with ignition off get a dead battery so quickly, high cranking current but not enough capacity to sustain the current draw. Luckily my residual current is now minimal with keys out but you are right, if the bikes charging circuit were to fail I wonder how long the 961 will keep firing on these lightweights.
  6. MxMartin


    Nov 13, 2017
    I have noticed that my bike is sluggish at first attempt but usually fires up. On the odd occasion that I need a 2nd attempt then it does seem to have more cranking power. I think it was Raphi or Pingu who said that it's best to warm up the Lithiums by turning ignition on and waiting for 30 seconds or so, the draw from the headlight is usually enough to warm up the battery.
    Voodooo likes this.
  7. Welshrugby


    Jan 18, 2018
    Just been out to trickle charge the battery, good job as I had left the heated grips on
  8. Fast Eddie

    Fast Eddie VIP MEMBER

    Oct 4, 2013
    Sir, any self respecting FWB has no need for such Tom foolery as heated grips.
    Britfan60 and Voodooo like this.
  9. Britfan60

    Britfan60 VIP MEMBER

    Jan 5, 2014
    So true, but a throttle lock to stick your hand in your pocket for a spell would be nice.

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