Upgraded to LiFePO4 battery

We had an Odyssey 925 battery just like a lot (most?) other -10 owners. It had been in service for two years so it was time to preemptively replace it. After much deliberation I decided to go with an EarthX ETX36 battery. They are relatively unproven in aircraft but not a complete wild card. Before investigating the topic very much I was eyeballing Shortai batteries and some other brands, which are indeed cheaper than EarthX, however they didnt have the integrated battery management system that I believe is important. Not to say I couldnt buy/make a BMS to stick on to those other brands, but I like what EarthX is doing and wanted to go that route. 

On paper its easy to see that my old battery weighs 26lbs and the new one is under 4lbs but it wasnt until I actually lifted the old one out and laid it onto my work bench with a hefty thud that I realized what a big difference the new one is going to make in the plane. I stuck the new battery in the same location as the original, which is behind the baggage wall per plans. I pop riveted a piece of angle onto the floor of the battery box to hold the new battery in place and was able to use the existing bar across the top of the battery after I cut the bolts down to size and re-threaded them. I'll have to snap a picture next time I've got that area opened up. We've been flying with the new battery for a few months now and over all I am extremely satisfied with the performance and weight savings of this battery. It cost more but its supposed to last twice as long so in the end I feel like I just got 20lbs out of the aft end for free! Win!

Comments (4) -

  • Hi Brian,

    Do you have any feed back on how successful your new battery has been? ( ETX36)
    Does it have the same grunt ?
    Do you find you need the battery charger on more while upgrading avionics software ?
    I was looking at the ETX48E until I saw your post.

    Also ,do you have any feedback on the EFII ignition system ? Were you able to go  LOP any further ?
    I all ready have the dual groove flywheel with Robert's magnets already fitted and had planned this for next year.

    Thanks for taking the time to up grade your website and share your experiences

    Thanks in advance for your reply

    Kind Regards,

    Ashley Miller
    • Hi Ashley,

      I'm very happy with its performance so far. It seems to have the same grunt for starting the engine. I havent had to hook a charger up to it at all yet - if i'm playing with avionics its usually for only 10 minutes or less and it handles that just fine. I need to and plan to do a test by leaving all avionics on and see how long it lasts. I did something similar with the old Odyssey battery and it lasted about 20 minutes.

      The EFII has been great. It saves us about 1.5GPH and the engine runs and cranks up much more smoothly. LOP has been easier so we typically run about 10.3 GPH at 160kts true.
  • Hi Brian,

    I went to place an order with Kathy at EARTHX for an ETX36E and received this reply,If you have a concern,give her a call,
    I have heard of some builders using 2 x ETX36E in parallel ...maybe an option.

    ( I am sure she means VANS and not RANS Smile  )



    Hi Ashley,

    I was just on the phone with the engineers at RANS discussing the battery choices for the RV-10 about 10 minutes ago. Your timing is amazing.  Also, I am not sure who is using the ETX36 series in an RV-10 as that would be undersized and all of the ones I am aware of, use the ETX48E.

    Please know, the ETX36E is designed for a 60 amp alternator or smaller. The RV-10 uses a 70 amp alternator or larger.
    The ETX48E is designed for a 120 amp alternator or smaller,  has 24  true amp hours as a deep cycle use in the event of your alternator failing, and 600CCA.
    The ETX36  has 12 true amp hours as a deep cycle use which is less than 50% of the capacity of a lead acid battery typically used  for the RV-10 and 405CCA.  
    The typical lead acid battery used in the RV-10 has between 21.6-32 true amp hours as a deep cycle battery, and 330-540 CCA’s.

    The ETX36 series is  undersized for your plane and it not designed to withstand the amount of amps the alternator can put out nor does it have the capacity needed if you were using the battery without an alternator. The use of an undersized battery in any application causes premature battery failure and can over stress the cells and cause failure as well. In an aircraft especially, this is not an area to cut back on.  The battery is the most used and abused part of the charging system and one of the most important parts.

    Based on performance, longevity and safety, I recommend you only use the ETX48E and as much as we want your business, I would rather you buy a properly sized lead acid battery than an undersized lithium battery if cost is the major factor. Also, the ETX36 series is not covered under a warranty for the RV-10 as it is the undersized and not designed for it’s charging system.

    Your satisfaction and safety is very important to us at EarthX and we know the ETX36 is not the correct battery for your plane.

    Kathy Nicoson
    EarthX Lithium Batteries
    Global Sales Director
    (970) 301-6064
    Fax: (970) 674-9544
    Facebook https://www.facebook.com/earthxbatteries
    Website: www. Earthxmotorsports.com
    Email: sales@earthxmotorsports.com
  • Hi Ashley,

    We have a 12-volt, 60 amp alternator from Plane-Power. It came with the Firewall Forward Kit. Perhaps these folks are not clear on what aircraft type you were asking about.

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