EarthX Lithium Iron Phosphate Batteries


I recently became aware of a great battery alternative for Glasair owners. Here is the statement from their website.

About EarthX

“EarthX, Inc. is a US company based in Colorado. The company was founded by an electrical engineer and a mechanical engineer who are passionate about riding and wanted a better alternative than the 170+ year old lead acid technology. The desire to remove weight was also very important and after years of research and development, EarthX launched a full line of lithium batteries for all your power sport needs. We are proud to be an American company with a mission to have the highest quality and best performing lithium battery in the world!”

ETX36D vs. PC 680

A couple of years ago Ted Setzer told me about the Shorai Brand Lithium Iron Phosphate battery he was installing in his Sportsman instead of the Odyssey, mainly because of the huge reduction in weight. There is a downside to the Shorai and other L.I.P. batteries however, and that is they are very sensitive to over discharging and over charging. So Ted decided to also opt for a more expensive B & C alternator because that allowed him to use their external voltage regulator that has an adjustable output capability.


Then just a couple of months ago, I found out about the EarthX batteries from a couple of brothers building a new Two Weeks to Taxi Sportsman. They told me the EarthX batteries have all the advantages of L.I.P. batteries, but also have a built in Battery Management System that totally takes prevents over charging and over discharging the batteries, especially in the kinds of service demands placed on them in our experimental aircraft.

ETX36D vs. PC 680

“EarthX has patent pending technology that makes it the most advanced lithium battery; the highest cranking amp cells; and the only one with a built-in BMS for performance, safety and longevity! This is not an upgrade or optional feature but a REQUIREMENT for a lithium battery to operate correctly.”

In January 2015, I called EarthX Motorsports and spoke with Kathy. I told her about our community and purchased an ETX36D. That is the closet to the dimension of the PC 680 that I have been using since my Sportsman was new. I used to keep my PC 680 on a battery maintainer when in the hangar and I have had good service from that battery type, but when starting a cold engine, I have to two engage the key twice to get the engine to turn over. I do have a lighter weight composite prop and I know that has something to do with it.

However, the EarthX battery will crank the engine on the first application of starter power and does so with gusto.

Here is what I like most about the EarthX compared to the Odyssey.

  1. Much lighter weight: 4 lb compared to 15 lb (ETX36D vs. PC 680)
  2. Holds a full charge without trickle charging.
  3. Rapidly turns over the engine even when cold. Cold Cranking amps are 405 compared to 170 for a PC680.
  4. Battery Management System built in to protect from over charging and over discharging.
  5. Great customer service from a company that is actively seeking to work with experimental aircraft community.

The cost is higher, but for anyone wanting to reduce weight I think it is a great choice.

EarthX Comparison Chart
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Alan Negrin
Alan is a full-time flight instructor and airplane broker and operates the Glasair Training Company out of Kirkland, Washington, but can be seen all around the USA and Canada as he helps new owners with transition training or first flights. He was formerly a demonstration pilot at Glasair Aviation.


  1. I’ve been using Odyssey batteries for some years, and have found them to function quite well. Also, they’re obtainable locally, usually at many battery stores. I’m contemplating the EarthX, due to weight saving… but does it need to be trickle charged? I’ve always left a trickle charger (Odyssey brand) running on mine.

  2. I confess that I don’t fly as often as I should. This makes for a meaningful testimonial to the effect that the Earth-X lithium-iron battery holds a charge very well and does not seem to need a trickle charge. Even in cold Alaska. The only time I ever had to jump it was when I left my Avionics bus in Clearance Delivery position, which draws from the battery side of the Master solenoid. Radios drained the battery. No problem after jumping the plane with my lithium battery jump starter battery that I keep in my truck and now take with me when flying out somewhere remote.

    Brad Cruz

  3. I tried an EarthX battery because the Odyssey PC680 just wasn’t strong enough to turn the Superior XP-400 when the engine was cold. I had some problems with the battery right out of warranty and didn’t feel like EarthX was very supportive of their product. I also think I was pretty foolish to have installed the EarthX battery in the first place because of the battery’s self protection feature. If you run the battery down to about 10.5 volts it will shut off to protect itself. My aircraft is mostly electrical so I installed dual B&C alternators. Even so, if I fail both alternators, I’m down to battery power. I have a back up battery for each of my Dynons but no other back up battery. I have dual Lightspeed 3 ignitions which will fire just fine down to about 5 volts which wouldn’t have been served well by a battery that cut out at 10.5 volts. Maybe no big deal if you run magnetos or some self powered ignition. To get the cranking power out of an Odyssey battery, I went with a PC 950. Great cranking power and huge reserve power. The point of all of this is to evaluate your own electrical requirements and decide if you are going to be OK with a battery that saves itself instead of saving you.