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    Luna Wolf Pack battery documentation

    The Wolf Pack is the first in Luna's lineup of next-generation ebike batteries for kits.
    • Greatly increased waterproofing
    • Greatly improved impact resistance
    • True cell-level fusing
    • Wire-bonded cells connected using same technology as Tesla rather than spot-welded
    • Steel reinforcement rails built directly into pack
    • All electrical components directly on pack for greater durability vs having some on cradle
    • New neodynium magnetic mounting solution
    • Recessed bottom of pack so magnets do not add to pack height
    • Capability for highly improved theft resistance thanks to reinforcement rails
    • Uses high quality XT connectors such as would be found on our softpacks, including Spark-Resistant XT90-S on discharge

    Waterproofing and Impact Resistance
    Unlike all previous hardcase batteries this is fully potted which greatly increases the ability to stand up to the high rigors of electric bike use including drops, crashes, and exposure to the elements.

    Cell-Level Fusing
    If something were to happen to a cell within this pack such as damage, that cell is immediately isolated from the rest of the pack. See below for further description why this is important.

    Wire-Bonded Cells
    The enemy of any battery is heat, and while spot welding is a step up from soldering onto a cell, we can do better. This battery is wire bonded using the latest in ultrasonic technology so the cell does not even get warm. Each connection is checked multiple times using automated sensors built directly into the machine for the ultimate in quality control. Thanks to this tech we build in the USA which means greater control over end product and greater access to spare parts and replacement parts. For more info click this link

    Steel Reinforcement Rails
    The rails on this battery have two separate purposes. With previous hardcase batteries we have noted that reinforcement can often be good for long-term durability so these rails were built directly into the design and zip ties can be run from these to the downtube. This not only is good for mounting within the downtube and increasing rigidity, it greatly increases the ability to mount the battery on the underside of the downtube so it is compatible with more frames.
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    Locking the battery
    This is also capable due to the rails. Typically a hardcase battery such as a shark uses a standard lock with a series of plastic tabs holding it in place. For regular use this is fine but a determined thief could remove the battery simply by kicking it on the side and breaking those tabs. With the new Wolf pack a special type of highly theft-resistant lock can be run through these reinforcement tabs and around the downtube thus preventing that from happening (click here for the listing)
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    Additionally this can be locked with the Hiplock Z Lok in the same way.

    Centralizing Electrical Components using XT connectors
    With previous hardcase packs the connection between the case and cradle was a point of vulnerability. Over time and use the contacts had the potential to get worn out and need to be readjusted, or various pollutants such as road salt could interfere with this connection. Wolf pack removes this obstacle by removing the connection between case and cradle, the discharge wiring goes directly out of the battery to the controller.

    XT90-S and XT60 connectors are standard as well. Whereas on previous hardcase batteries a charge port could wear out due to mechanical fatigue this is eliminated using an XT60. And XT90-S on discharge is the gold standard of ebike connectors utilizing an antispark design.

    Neodynium Magnets
    These magnets are very powerful and keep the pack affixed in place. They are around 10 mm in height and fit within the recessed bottom of the battery in such a way that it does not add to the battery height. The magnets are so strong that pulling directly up on the battery will not remove it, it must be intentionally removed by pushing the top at an angle.

    As an additional bonus because this is not a traditional cradle as typically seen on hardcase batteries, these two magnets can be moved and re-oriented with much greater flexibility for how this will be mounted. The mount holes do not need to be specifically placed in order for the the battery to be mounted to the same extent as previous versions, which means less likelihood of having to drill out the frame rather than simply using the existing water bottle bosses.Click image for larger version  Name:	fetch.png Views:	2 Size:	175.1 KB ID:	62527

    The magnets also come with spacers that can be used to help stabilize the magnets on the frame. These are optional but if you want to use them they go between the magnet and the frame. See below for a picture.
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    See below for a video demonstrating how to add and remove pack


    Fitment

    To create a printable mockup of this battery, download this pdf, print and cut along the dotted line.
    Tape together the edges and you have a full size mockup that can be used to see if it fits your frame


    This is a 14s4p pack configuration but in a significantly more compact package than a comparable 14s4p (52v) Shark pack. It can fit into many places a regular shark pack cannot or should not be mounted. For a video comparison of the Wolf pack to the Shark pack see below



    Troubleshooting

    The underlying architecture of the pack is closer to a softpack than a hardcase.
    Please see troubleshooting section of the Softpack Battery Documentation

    Battery Care and Storage

    Please see the Battery Documentation Master Repository

    Cell level fusing and why it matters

    From the moment any lithium cell leaves the factory it is subject to degradation. While there are things that can be done on a molecular level as well as an end-user level to inhibit degradation, nothing can prevent it fully. Below is a video of a dendrite forming within a cell. What is happening is this structure forms from the lithium on a molecular level between the positive and negative, consuming the liquid electrolyte in the process.



    While this is well known for being part of the cause of degradation that results in reduced lithium capacity over extended usage, there is a second potential effect from dendrite formation. The dendrite can potentially puncture the separator that is on positive and negative. If that happens the cell would be internally shorted.

    Quality cells inhibit formation due to their makeup and have a quality separator to prevent this from happening as much as possible, as does treating your battery according to the recommendations. However, given that nothing fully inhibits dendrite formation, there is a possibility that over a long enough timeline enough dendrite formation will occur as to puncture the separator and internally a short a cell. This applies equally to all lithium batteries in existence, whether the ones in your phone, laptop, or ebike.

    So how does fusing come into play?

    Typically in a battery if a cell shorts internally the other cells will dump their power into that short. This causes it to heat up extremely fast and potentially cause a fire due to the flammable electrolyte. Wolf is designed using the latest technology to automatically remove any shorted cell from the circuit, preventing a short from turning into a fire. While there are a couple companies advertising cell fusing using cheap approaches none of that has been tested or confirmed by any studies or publicly available information. By contrast wire bonding is very well studied, the mechanism is very precise and reproducible under laboratory testing conditions, and is the subject of multiple patented technologies generously donated to the public by Tesla. Do not be fooled by crude imitations.

    Given that Wolf is also fully potted to prevent impacts to cells from causing a cell to be internally shorted, this battery has multiple new safety advantages making it by far the safest ebike battery to have ever been built.
    • High quality cells to mitigate dendrite issues
    • Potting to prevent cells being shorted due to physical damage
    • Ultrasonic cell connections do not heat the cell unlike spot welding (heat is conducive to dendrite formation)
    • Cell level fusing prevents a fire in the event of an internal short due to degradation


    Potting and why it matters

    Potting is the process of pouring a liquid into the battery that then hardens, similar to epoxy. This provides an unparalleled level of impact resistance. This is done on all Luna Wolf batteries as well as all Luna Fusion batteries. See below for an example where a potted battery was ran over by a tank and thrown across a parking lot multiple times, and still functions perfectly. This is only possible with a potted battery and we would not even think of doing this with a regular battery.



    Does potting trap heat?

    At Luna we only use the best available potting.
    While cheap potting may trap heat, quality potting will do the opposite, i.e. it is thermally conductive.
    The picture below shows a typical BBS02 mid drive bike after a hard ride.
    While the controller reached 107*F, the Wolf stayed room temperature.

    https://media.rivet.works/743a0888118d4875ae6fee4d1f741a37.jpeg

    See link to this battery here
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