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Part# 11-13926
MFR Model# ETX900


Note: Not FAA Approved. Intended for use in experimental aircraft only.

The ETX900 is lightweight and crazy powerful!

This battery is intended for 540ci engine size or less; 80 amp alternator/generator or less.

The ETX battery series is fully protected by an integrated battery management system (BMS) that protects the cells from over discharge, overcharge, short circuit, temperature, plus cell balancing to ensure charge levels are equal. Additionally, our ETX Hundred series aircraft batteries have redundant electronic circuits and battery fault indication. The fault indicator can be connected into your EFIS or wired to a 12volt LED light on your control panel to alert you to the state of charge and state of health of the battery. (Please see manual for details)


  • The ETX Hundred series is fully protected by an integrated Battery Management System that protects the cells from over discharge, over charge, short circuit, thermal protection and built in cell balancing to ensure charge levels are equal (balanced) 100% of the time for optimal performance
  • and life.
  • The most trusted and used lithium battery on the market. Multiple experimental aircraft manufacturers and experimental engine manufacturers such as Rotax Engines, Continental Motors, UL Power Engines and Viking Engines approve the EarthX brand.
  • LiFePO4 chemistry, the most abuse tolerant of all lithium battery chemistries.
  • Higher voltage while cranking mean faster starts.
  • Extremely light weight, 70-80% lighter than your lead acid battery.
  • 4,000 charge cycle life versus 350 charge cycle life of a lead acid battery. Can last up to 8 years.
  • Environmentally friendly, no hazardous lead or acid, will not corrode or sulfate.
  • Wider operational temperature range than a lead acid battery. (-22 F to 140 F, -30 C to 60 C) . A lead acids operational range is(-40 F to 113 F or -40 C to 45 C).
  • Vibration tested to DD-311 FAA standard.
  • Low self discharge rate and fast charging.


Voltage 13.2V
Capacity 15.6Ah @ I C Rate (See charts Below)
Capacity vs Temperature 25C= 100%
0C= 92%
-30C= 80%
Self-Discharge Rate <3% / month @ 25C
Pulse Crank Amps (PCA) 840A (3 sec @ 25C, voltage >9V
Cold Crank Amps (CCA) 400A (modified SAE test, 3 sec @ 0F, volts > 7.2V)
Continuous Discharge Amps 150A
Standard Charge Voltage 13.9 - 14.6V
Maximum Charge Voltage 15V
Recommended Charge Voltage 5 - 20A
Max Charge Amps 80A (from vehicle charging system)
Life (Charge cycles, 80% depth of discharge) 4000 cycles @ 1C discharge rate,
25C 2000 cycles @ 10C discharge rate, 25C
Life (Years) 8 Years
Weight 4.9 lb. (1.8kg)
Dimensions 6.5 in (L) x 3.1 in (W) x 6.6 in (H)
166mm (L) x 79mm (W) x 168mm (H)
Environmental Rating (resistance to water intrusion) IP 66 (wash down with a high pressure washer)
Operating Temperature -30C to +60C
Storage Temperature -40C to +70C

Why Choose EarthX

  • You will instantly remove 11+ pounds compared to the lead acid battery in your experimental aircraft! Now that is a huge weight savings.
  • Significant increase in cranking power. If you have been using the PC680, you will increase your CCAs from 170 to 320 and the PCAs from 520 to 680! Now thats power to crank your engine!
  • Now you can easily have a backup battery and not worry about the additional weight. In fact, if you switch from a lead acid battery and add a backup battery, so you have a primary and a backup, you still have decreased your overall weight by 50%! Note that only the ETX680C/680/900/1200 have the aircraft specific BMS.
  • Innovative and sophisticated BMS designed and engineered with redundancy for safety, reliability, and performance. These are EXCLUSIVE features!
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Wild power, low weight. Nothing we have used compares

Decosse C Verified Purchase


June 25, 2021

Great battery. Very light weight. Lots of cranking power.

Kevin W
April 20, 2021

We put this battery in a Xenos with an Aerovee Engine. WHAT difference for cranking amps. Now we never have a problem getting the motor running. Also, Im in charge of maintenance for 3 planes - 1 certified and 2 experimental. Ive never had a time where Aircraft Spruce didnt have what I needed. Thanks!

October 16, 2020

Getting this EXT- 900 Aircraft battery and the battery box that was made for it was a very wise decision. It is so light, it shaved about 10 or more pounds off my gross weight and gave me room for 10 pounds more useful load. So glad I decided to go for the lithium battery this time. It was a little more expensive but well worth the cost.

Floyd L
August 10, 2020

This is my 4th battery and I am super pleased. I have had Oddesey batteries to start my Superior IO-360 in my Experimental GlaStar. They were always sluggish and lasted only 2-1/2 years at best. I started with the PC680 and then to the 26 lb PC925 which wasnt much better. The EarthX was a massive change. With the EarthX, the prop did not stall and the engine started on the 2nd revolution. Additionally the reduction in weight allowed the CG to shift to an optimum position and allowing me to again increase my cargo load to its full 250 lb capacity. Im very pleased.

Gus G
July 21, 2020

In a word WOW. I am building a Rans S-19 and was having trouble getting the engine to start for a test run using a lawnmower battery that I had available. NoJoy. I decided to purchase the earth X battery and was blown away by the cranking power. The JABIRU started right up.

John M
February 23, 2020


Please note, Aircraft Spruce Canada's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce Canada assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.

Q: Does the EarthX ETX-900 come with terminal bolts?

The terminal screws are included.

Q: Are any of the EarthX batteries for certified aircraft?

Yes, the ETX900-TSO is FAA TSO approved. Please see our part # 11-18242.

Q: ETX lithium batteries adv. their redundant electronic. circuits: Q - What circuits EXACTLY have been duplicated on the BMS?

The discharge power control circuits.

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