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    Shark PF LVC

    When connect to a BBS-HD what is the LVC for a Shark 11.8 with PF cells?
    My new Shark 11.8 with only a few miles cut off around 45 volts and brought in a Error 30... changed to another battery and the BBS-HD ran fine
    Is this the normal LVC on the Shark 11.8?

    #2
    Is it a 48v or 52v shark?

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      #3
      The Shark is a 52 volt 11.8 with PF cells

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        #4
        Cut off is around 40 volts but you are going to get voltage sag at high power so the pack might cut off sooner when under load. So 45 volts might be normal. A 48 volt pack has a lower cut off than a 52 volt pack.

        If you want to make sure your battery is good you need some kind of amp hour guage. Look at the watt meter and the batt man for an affordable amp hour guage...or the cycle analyst for a full featured one: http://lunacycle.com/guages/

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          #5
          Thanks, I will check that today with a remotely shunted Volt/Amp meter

          IMHO, maybe the reason 48v to 52v battery upgrades can be counter intuitive is because the c961, c965 or c9xx "fuel" gauge is optimize for 48v - 13 cells

          Assuming that is correct, a c9xx connected to 52v Luna Pack will still show plenty of available battery when the BMS LVC activates.

          In addition, because LED gauge on the Shark 52v pack is still the 48v rated unit, LED's reflect a higher voltage battery condition that exist at LVC.

          Could be confusing... and in my case a very long hard walk in the woods for a 70 year old pushing a large Fat Bike,

          Is there any way to adjust the c9xx "fuel" gauge(s) for 52v ?

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            #6
            The Shark 52v 11.8 PF charged up A-OK... so it when for a snow bike ride
            During ride test ride, a remotely shunted volt - amp meter was used so the actual voltages and amps can be observed real time
            Near the end of the ride when the BMS had its first LVC power off, the bike was stopped and the "static" voltage on digital meter display was noted at 47.8 volts

            From a stopped position, when throttle was applied to more than 6 amps, the meter display voltage immediately dropped to 45 volts and the BMS LVC activated and cut the battery power

            It maybe worth noting that at the exact moment(s) of BMS LVC power off the meter flashed 44.7v. 44.9v, 44.8v and 45v on all test

            Is the 47.8v "static" and the 45v BMS LVC too high for a Panasonic PF cell? (Panasonic specs note a 2.5 discharged voltage rating for that cell)...

            How much tolerance to manufactures allow for their 14 cell LiPO BMS when 40v LVC is noted in the specifications?

            Assuming that a replacement BMS would have the correct 40v LVC... Should I replace the Shark BMS or the Shark BMS LVC programmable?

            Comment


              #7
              This was just asked in another thread regarding an accurate 52v gauge and as far as i know there is no way to reprogram the bafang display for 52 volts but i am asking this question straight to Bafang.

              Since we sale mostly 52v batteries with bafang drives now we could have future displays programmed to 52v.....and maybe even come up with a way that users could flash there 48v displays to accurately read with a 52v battery.

              This is interesting your battery seems to be cutting off at 45 volts which seems a bit high. Which watt/amp guage are you using? Do you know the amp hour output you are getting on the battery?

              We started selling a new product called the Battman which is small enough to mount on the handlebars next to the Bafang 961 963 or 965 and is an accurate battery guage plus will give amp hour readings:

              See the batt man here.

              Comment


                #8
                It would be nice to know how many amp hours have come out of the battery when a 6 amp load sags the voltage down to 45 volts. If you didn't do anything else, you'd have to have a light touch on the throttle at some point, when the battery was discharged X amount. Problem is, when you get deep sags they will get pretty deep quickly, and it's better for the battery to keep things in as safe a zone as possible. If you knew how the battery was sagging when you had 40%, 30%, and 20% left, you'd know a lot more. The 6 amps is 300 watts, so not much performance. The only meaningful number for batteries is amp hours, a lot of the time.

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                  #9
                  Originally posted by eDavid View Post
                  . and in my case a very long hard walk in the woods for a 70 year old pushing a large Fat Bike,
                  Just curious, how far did it take you before cutting out?

                  Comment


                    #10
                    I experienced something similar on my very first ride. At the time I had my custom remote Watt meter installed. I started out with 50V on my pack because I just got my Luna charger. I didn't go far but I went farther than intended and the power cut out. It was dark out, all I remember is the C965 display indicated an issue, I shut it off and the pack thinking I hurt something. While pedaling home I thought to turn on my 52V Luna Dolphin Panasonic PF pack and the bbshd controller. Everything worked fine again. I think the voltage sag messed up my controller and all I did was allow the battery to recover from the voltage sag. I used power sparingly and when I got back my battery was at 45.8V. I think the pack LVC may cut out at 40V but I wonder if bbshd controller has issues with power use around 45V. I don't go below 48V now that I'm doing my commute and charging before I ride. I've read that I should keep my cycles between 80%-20% for best battery life, I think that is 56V-50V from what I've researched on www.batteryuniversity.com. I will follow this thread as it's possible I'll be put in that situation again.

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