EarthX

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Posts posted by EarthX

  1. Posted

    Lithium Ion is a generic term and could refer to any battery made with “lithium” as one of the components. Here is some of the common commercially available lithium batteries:

    Lithium Cobalt Oxide (LiCoO2)

    Lithium Manganese Oxide (LiMn2O4)

    Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2)

    Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO2)

    Lithium Titanate (Li4Ti5O12)

     Lithium Iron Phosphate (LiFePO4)

    A “lithium” battery is the most commonly used power source in today’s technology and is not new technology. It has been used extensively since the 1970’s, mainly by the military (as they were the only ones who could afford it). They power many medical devices (such as Pace Makers), cell phones, lap tops, engine starting and main power sources to name a few. Most RC cars use Lithium Cobalt Oxide, not Lithium Iron Phosphate which is the chemistry used in the EarthX brand. The reason behind using LifePo4 as a starter battery is:

    • Safety- It is the most abuse tolerant of all the Lithium Ion chemistries -- one of the highest thermal runaway thresholds 270°C (518°F).

    • Practicality –each charged cell is 3.65V, so four cells in series is the correct full-charge voltage for a starter battery at 14.6V

    • Longevity  - cycle life (2,000+ depending on DOD)

    • High Discharge Rate

      The disadvantage of using a LifePo4 battery is:

    • Specific energy is less than that of other Li-ion

    • Self-discharge is higher than other Li-ion batteries, but still better than other battery types

    • Cold temperature operation can also be an issue with Li-phosphate as a starter battery

        (below 0 deg F)

       

      As Knuckledragger mentions, it is important to protect the cells which is why EarthX has not only one (BMS) battery management system but 2 for redundancy that is controlled by a microprocessor. There is also an LED battery fault light indicator that alerts you to the state of health of your battery and state of charge.  The BMS protects from over discharge, overcharge, short circuit, cell balancing and excessive cranking (heat) plus has the ability to alert you to a possible problem with the battery with a red LED light that would illuminate if you need to evaluate your battery. We also have HIGHLIGHTER yellow stickers you must remove in order to install the battery that warns you not to use a defective battery and it is all also located in many places such as the packaging, manual, FAQ etc.

      If you did ignore all of the warnings and proceeded to use a defective lithium battery where you are pushing a possible 120 amps through it, yes, it can have what we call a catastrophic failure as it can cause the cells to rupture and produce smoke and/or flames. A lead acid battery can also have a catastrophic failure and explode acid all over, and if you ignore the fuel gauge and try to continue to fly without gasoline, you will also have a catastrophic failure. 

      “Lithium batteries are not ready for aircrafts.”  Here’s a thought: if you have flown on a commercial flight in the last 15 years, you have had hundreds of lithium batteries in that aircraft alone from the cell phones and laptops onboard. Now if you add up the amount of flights around the world daily for the past 15 years with each of them having hundreds of lithium batteries on board…...the amount of incidents are very rare.  Technology advancements are great and where would we be if we didn't have people like the Wright Brothers, or Boeing? 

    Sincerely,

    Kathy at EarthX

  2. Posted

    Did you ever hear back from EarthX about this?

    I just did... I was emailed by our latest member to sign up on the forum (earthx).... I called and talked to the person who emailed me and she was unable to answer any of my questions but at my request or prompting she has said she will have the "engineer" who dealt with this issue post up here to state what they believe was done wrong that led to the melt down.

    I will wait to see what they post up here before further elaborating on the subject.  I can tell you that despite being asked to remove this thread I will leave it up for all to see the answer and I am sure future responses to this thread.

     

    :BC:

    Dear AvidFoxFlyer subscribers,

    We recently had a customer contact EarthX about this forum and requested we respond to the thread as he felt it would be very beneficial to do so for potential customers. As an experimental aircraft builder, you have many choices of what to use to build your aircraft. As a manufacturer of experimental aircraft batteries, EarthX does many things to help assist you in deciding what battery is the best option for you.

    In this particular situation, we warn to not use a lithium battery with an engine designed for pull start only or a vintage engine that uses Magneto type charging systems as it is not compatible. Here is the link from the website under experimental aircrafts where you can read the technical reasons behind this:  http://earthxmotorsports.com/engine-charging-systems-use-lithium-batteries. Here is also a quote from this article, “Simply put, if the engine was designed for a pull start, do not use a lithium battery, if the engine was designed for an electric start, it is acceptable to use a lithium battery.”

    We also have an experimental aircraft page http://earthxmotorsports.com/product-category/experimental-aircraft that first line reads “Only the ETX Hundred series -( ETX680C, ETX680,  ETX900 and the ETX1200) are recommended for your primary engine aircraft battery due to the internal monitoring and redundant BMS electronics.”  The battery used here was the ETX12A that has a max charging amp rating of 20amps, which this particular system was much higher than that. There is also a 22 page manual with lots of details about the products and their uses on the website. We do try to educate and assist in choosing the correct battery for your plane, but in the end, what you choose is your choice. (A gasoline engine says to not use Diesel fuel but if someone does, there will be issues).

    In this particular situation, and based on customer service, EarthX did have an Electrical Engineer review the schematics for this customer which had many things that needed to be addressed in the modifications done, lithium battery or not, and he was told that a lithium battery, not just the EarthX brand, can not be used in his aircraft and we refunded his money.

    Lithium batteries can be a great alternative to a lead acid battery if it is compatible with your aircraft and designed to work within the parameters specified.  EarthX has been approved for use by Rotax, the largest experimental aircraft manufacturer in the world for the 912 engines, and also has been approved by Continental Motors, UL Power Engines, Viking Engines and Aerovee Engines. EarthX is also being used by over 20+ OEM (original equipment manufacturer) such as Sonex aircraft, Kitfox Aircraft, Mosquito helicopters, Viking Aircrafts etc. and this number is rising. Please, if you have questions about use and if it works with your aircraft, and you cannot find the answers you seek, contact us directly at (970) 674-8884 or at sales@earthxmotorsports.com.