EarthX Inc

If you are asking about EarthX, we are in good old Colorado USA, and a veteran owned business too if that is of interest.

We appreciate that using a lithium battery in your Mooney may seem novel and new and raises questions. That’s exactly why we are here on this forum, to address your questions directly and provide clarity. Advancing technology often feels uncomfortable because it challenges what we’ve always known. We welcome questions, but it’s important to base discussions on facts, not assumptions. LiFePO₄ technology is proven and trusted in aviation. LiFePO₄ batteries have been in use for over 50 years, starting with the U.S. military, and EarthX alone has logged more than 25 million flight hours across tens of thousands of aircraft over 12 years. Every safety and compatibility consideration has been addressed. LiFePO4 batteries use the same charging profile (voltage) as lead-acid, so no alternator or regulator changes are needed. The internal resistance of the ETX900-TSO is approximately 4mOhm. The internal resistance of the Concorde RG-35AXC is also approximately 4mOhs. We hear your concern that this new technology might damage your 50+ year old alternator. The EarthX Mooney’s typical peak charge is 15-20 amps that lasts about 3 minutes. EarthX is particularly fond of the Mooney aircraft and is a proud owner of an M20K with an EarthX battery in it for 3 years now. Up until now, you had no choice but to use a lead-acid battery in a certified aircraft, and the companies that cornered this market had no competition. Competition is good. It breaks monopolies and creates opportunities for better solutions. When companies compete, they strive to create better products that improve safety, reliability, efficiency, and deliver advancements.

You are welcome and thank you for taking the time to say this, it does mean a lot to us.

Per the TSO testing and approval, and the STC testing and approval, there is no need to have limits on the charging amps. The battery is designed to accept the alternator output which also tested and approved to function as they state.

Thank you all for your participation in this thread and all the questions. Please note we provide answers to your questions via the manual; FAQ page; FACT SHEETS; and YOU TUBE channel to educate users on their charging system and the role of the battery to provide understanding and information. The extensive process and expense for any manufacturer to receive a TSO (Technical Standard Order) approved product, is a deep dive into the DESIGN of the product and verification of its functionality, reliability and safety. The next step in the process is receiving an STC (Supplemental Type Certificate) for retrofitting existing aircraft (such as the Mooney’s here) or a TC (Type Certificate) for new aircraft (such as the Cirrus G7 and SR20’s aircraft). This is where the real expense and time comes in as it must be completely and thoroughly tested to work as designed within the system it will be used in which includes the alternator and regulator, starting performance, and critical situations, such as an alternator failure for examples. This process requires FAA DAR’s (Designated Airworthiness Representatives), DER’s (Designated Engineering Representatives) and a plethora of other experts. The barrier to bringing new technology and improvements to the certified aircraft market, from regulatory, to the expense, to the time involved, is why many manufacturers choose not to pursue it. EarthX currently has over 350 airframes with STC’s and more are on deck for 2026 and you will see many new aircraft come standard with an EarthX battery in the future. We believe in the certified aircraft market and have committed to the process of what it takes to bring this technology to you as an alternative. The EarthX battery that is TSO’d and STC’d for your aircraft has been thoroughly designed and tested to work in your aircraft. (it does not “eat” your alternator).

Eventually but we are so busy with the FAA STC's at this time we just don't have the resources to do it, plus, we are waiting until we have most of the STC's we are pursuing to do it all at once. We currently have over 350 aircraft with STC's and by end of this year, should have almost all of the main ones we are seeking.

That battery is for the turboprop or small jet market, the one that is pertinent for the Mooney's will be the ETX680-24-TSO at $999 for the 24V models. Aircraft Spruce is great but they are simply a catalog website, for information about the batteries. please use our website for the most accurate news: http://www.earthxbatteries.com

Great question and our certified battery for this replacement is the ETX680-24-TSO, weighs 7.2 pounds and costs $999. This is the battery that all of the Cirrus G7's and new SR20's come with.

Hi Mike, I hear you and understand your concerns! In all seriousness, please share what your essential load amp draw would be after you reduce your electrical loads to a minimum in the event of a total power failure in flight. Next, how many minutes do you need/want to find a practical place to land? With this information, it can be mathematically calculated what you would need in a battery for reserve capacity to achieve your outcome. This will be very important information for all to know and why we stress how important it is to know what your essential load amp draw would be so you do not ever guess how long you have to land, you know.

That is a great question for your IA mechanic. They have the authority to adjust an STC and sign off on any "variance" of an installation. Is there any IA mechanics on this forum that can answer this question?

Thanks for the question and there are no limitations on where the battery can be located now and we do have FWF STC's currently. To have a TSO'd and STC'd product, the amount of testing is intense, extensive, and expensive and before the FAA granted us the no limitations on location authorization, we did need to pass all testing they asked to satisfy their requirements. This process just takes time ,.....years actually. (Side note: we are the only company in the world that has this no limitations on location authorization for certified aircraft and a lithium battery installation).

Great question and there are no plans at this time to make a higher capacity option in the 12V market.

We are hopeful to receive this next STC batch of approvals in next couple of months but we never can predict the timeline of the FAA!

HI Hank, I totally understand. Hypothetically, if you installed 2 ETX900-TSO's, you would have more capacity then the RG35-AXC as an option and still be only at 10.8 pounds vs. 32 pounds and have way more cranking power. I am very sorry you have had 2 electrical failures in the air! When this happened, how long did it take you to find a practical place to land? And do you know what your essential load draw was in these events?

We could not receive an STC without all critical safety considerations and requirements met. In the event of an alternator failure/power loss (which if this is a common event as you suggest, this should be a serious topic for the manufacturer of the alternator) the battery must have enough capacity to power the essential loads to continue safe flight so you can land as soon as practical. The minimum required time is 30 minutes. As a pilot, it is very important for you to know what your amp draw is in this situation so you can plan accordingly, regardless of what chemistry battery you use. And the capacity of your battery will decrease with time based on several factors, but environment is a big one (the hotter it is, the larger decrease of capacity with time). Example, if your essential load is 10 amps, with the EarthX battery you would have 93.6 minutes of operation to land. If your amp draw is 20 amps, you have almost 47 minutes to land. (It should be noted that the lead acid batteries with the high capacity is so they can meet the CRANKING requirement to start your engine). But all that being said, if you want more time to land in the event of a power loss failure in flight, then an EarthX battery may not be a good choice for you. With double capacity, you double your time to land.