MADE IN THE USA!
Free Economy ShippingProduct Specifications for EarthX ETX104 Backup Lithium Battery for Aircraft
| BM Part #: | ETX104 |
|---|---|
| Brand: | EarthX |
| Made In: | U.S.A. |
| Voltage: | 13.2 Volt |
| Capacity: | 4 Ah |
| Energy Capacity: | 51 Wh |
| Type: | LiFePO4 |
| Length: | 4.5" |
| Width: | 2.6" |
| Height: | 3.7" |
| Shipping Weight: | 1.30Lbs |
| Warranty: | 2 Year Factory Direct |
| Product Manual: | Download |
| Datasheet: | Download |
What's in the box:
- 1 x ETX104
- 2 x 6mm screws
- Made in the USA. Why it matters:
- Superior craftsmanship; rigorously tested; high-quality parts.
- Built-in current limiting: Protects the battery from high charge current no matter your alternator size.
- Full BMS protection: Guards against over-discharge, over-charge, and short circuits automatically.
- Cell balancing technology: Keeps individual cells even for consistent performance and longer life.
- Remote LED fault monitoring: Wire it to your panel or EFIS to track battery health at a glance.
- Lightweight design: Weighs just 1.3 lbs, cutting weight versus a comparable AGM backup battery.
- 2-year factory warranty: Backed by EarthX's full coverage warranty for lasting peace of mind.
Product Description
If your aircraft's electronic ignition, EFIS, or avionics bus needs a reliable second power source, the EarthX ETX104 is built for exactly that job. This 13.2-volt, 4Ah LiFePO4 battery is designed to back up your critical loads — not replace your main starting battery — so your essential instruments stay powered if your primary system ever falters.
Built-In Protection You Don't Have to Think About
Lithium batteries can be picky about charge current, but the ETX104 takes the guesswork out of it. Its integrated battery management system (BMS) includes built-in current limiting, so it plays nice with charging systems of virtually any size. You also get:
- Over-discharge and over-charge protection
- Automatic cell balancing for even charge levels
- Short circuit and excessive cranking protection
- Remote LED fault monitoring you can wire into your panel or EFIS
Weight Savings Without Cutting Corners
At just 1.3 lbs, the ETX104 sheds significant weight compared to a traditional AGM backup battery — a real advantage for homebuilders and owners chasing every ounce of useful load. It's compact too, measuring 4.5" x 2.6" x 3.7", so it tucks into tight avionics bays with room to spare.
Made in the USA, Backed by a 2-Year Warranty
Every ETX104 is assembled in the USA and backed by a full 2-year factory warranty. You're getting a battery built to aviation-grade standards, not a generic lithium pack repurposed for the job.
Give your critical avionics the backup power they deserve. Order your EarthX ETX104 today and fly with one less thing to worry about.
Fault Conditions
This table shows the most common fault conditions and possible causes.
| LED Light | Voltage | Possible Cause | Recommended Action |
|---|---|---|---|
| Slow Flashing (5s on / 5s off) | Less than 12.8V | Battery over-discharged (due to faulty charging system) | Charge battery. Once charged, the light will stop flashing. |
| Slow Flashing (5s on / 5s off) | Less than 13.2V | Weak or failing cell | Charge battery. If voltage drops below 13.2V within a few days, discontinue use. |
| Slow Flashing (5s on / 5s off) (>1 hour time period) | 13.2V - 14.6V | Weak or failing cell | Discontinue use. If in flight, this is not an immediate issue unless it is in conjunction with a charging system failure. |
| Slow Flashing (5s on / 5s off) | Greater than 15.2V | Over-charging (due to faulty charging system) | If in flight, shutoff charging system immediately. Aircraft over-voltage protection is required if alternator charging system is greater than 20 amps (i.e. over voltage crowbar circuit) |
| Slow Flashing (5s on / 5s off) | 13.2V - 14.6V | Cell to cell charge levels are not balanced | May come on briefly during periods of high current charging until the cells are automatically balanced. Try charging with a plugin charger, like an Optimate Lithium charger. |
| Solid Light | Any voltage | BMS electronic issue | Discontinue use. If in flight, this is not an immediate issue unless it is in conjunction with a charging system failure. |
| Solid Light that turns off after 3 minutes | Any voltage | Short Circuit protection was activated | Nothing neds to be done. |
| Short Flashing (2s on / 2s off) | Any voltage | High battery temperature (> 65°C / 150°F) | Let battery cool down prior to cranking or charging. |
Frequently Asked Questions
Is the ETX104 a starter battery for my aircraft?
A: No. The ETX104 is designed as a backup power source for critical loads like your essential bus, electronic ignition, or EFIS — it's not intended to crank your engine.
What's the maximum charge rate the ETX104 can accept?
A: The ETX104 is designed to accept up to 15A of charge current. If your aircraft's backup circuit uses a smaller breaker or fuse (commonly 10A on many factory setups), check that your wiring and protection devices are rated to handle the battery's charging behavior before installing.
Will the ETX104 work with my existing charging system?
A: Yes. Its built-in current limiting is designed to work safely with charging systems of virtually any size, protecting the battery from excessive charge or discharge current automatically.
What does the LED fault light mean?
A: The LED communicates battery status through different flash patterns — slow flashing, short flashing, or a solid light — each tied to a specific condition like over-discharge, overheating, or a BMS fault. Refer to the product manual's fault condition chart to match the pattern you're seeing to the recommended action.
How do I keep the battery healthy if my aircraft sits for a while?
A: Like all lithium batteries, the ETX104 can lose capacity if left fully discharged for an extended period. If you won't be flying for a few weeks or more, use a compatible lithium-specific charger or maintainer to keep it topped off rather than letting it sit unattended.
