MADE IN THE USA!
Free Economy ShippingProduct Specifications for EarthX ETX680C Compact Lithium Battery for Experimental Aircraft
| BM Part #: | LTX680C |
|---|---|
| Brand: | EarthX |
| Made In: | U.S.A. |
| Voltage: | 13.2 Volt |
| Cold Cranking Amps: | 320 CCA / 680 PCA |
| Capacity: | 12.4 Ah |
| Type: | LiFePO4 |
| Length: | 5.9" |
| Width: | 3.4" |
| Height: | 4.5" |
| Shipping Weight: | 3.90Lbs |
| Warranty: | 2 Year Factory Direct |
| Product Manual: | Download |
| Datasheet: | Download |
What's in the box:
- 1 x ETX680C
- 2 x 6mm screws
- Foam for proper fitment
- Made in the USA. Why it matters:
- Superior craftsmanship; rigorously tested; high-quality parts.
- Compact C-Case Design: Measures 5.9" x 3.4" x 4.5", fitting installations where the larger ETX680 won't.
- Exceptional Cranking Power: Delivers 680 Peak Cranking Amps and 320 CCA for reliable starts in temperatures as low as -22°F.
- Significant Weight Savings: Weighs just 3.9 lbs, replacing lead-acid batteries that can weigh 15 to 30 or more pounds.
- Integrated Battery Management System: Automatically protects against overcharge, over-discharge, short circuit, and cell imbalance.
- Fault Indicator Pigtail Included: Connect to an LED panel light or EFIS to monitor battery health in real time.
- Rotax-Approved and Made in the USA: Engineered and assembled in America, meeting Rotax engine lithium battery requirements.
Product Description
Got a tight battery compartment? The EarthX ETX680C is built for exactly that. It delivers the same 680 Peak Cranking Amps and 12.4 Ah capacity as the ETX680 — but in a more compact C-case that's over 2 inches shorter in height. If your build requires a smaller footprint without sacrificing power, this is your battery.
At just 3.9 lbs, the ETX680C is one of the lightest aircraft batteries available. One customer replaced two Odyssey lead-acid batteries with a single ETX680C, dropping from 30 lbs down to 4 lbs. That kind of weight reduction changes weight and balance calculations in a real way.
What's the Difference Between the ETX680 and ETX680C?
The electrical specs are identical. The only difference is physical size. The "C" stands for compact — the ETX680C measures 5.9" x 3.4" x 4.5" versus the ETX680's 6.5" x 3.0" x 6.6". If your aircraft uses a C-case battery tray, or if you simply need that shorter height, the ETX680C is the right choice. Both batteries sell at the same price.
Built-In Protection You Can Count On
The ETX680C includes EarthX's integrated Battery Management System (BMS), which protects against overcharge, over-discharge, short circuits, and cell imbalance — automatically. No external protection hardware needed.
Like all ETX Hundred Series batteries, it also includes a black pigtail fault indicator wire. Connect it to a 12V LED light on your instrument panel or to your EFIS, and you'll get a visual alert if anything moves outside the normal range. The EarthX 5MM12 12V LED Battery Fault Indicator Light is available separately. Full wiring details are in the product manual.
Rotax-Approved and Designed for 60-Amp Systems
The ETX680C is approved for use with Rotax engines and is designed for aircraft running a 60-amp alternator or less. Before purchasing, confirm your alternator output. If your system exceeds 60 amps, the ETX900 series would be a better match.
Compatible C-Case Accessories
- EarthX 5MM12 12V LED Battery Fault Indicator Light
- BB-TH-CO Thermal Battery Box for C-Case (FAA PMA Approved)
- Adapter-CDE Terminal Adapters
Engineered and assembled in the USA, backed by a 2-year factory warranty, and shipping free to all 48 contiguous states. Add the ETX680C to your cart and take back the weight.
Typical Charging Times
| Charging Amps | Charging Time |
|---|---|
| 1 amp | 12 hours |
| 5 amp | 2.5 hours |
| 15 amp | 45 min. |
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
What is the difference between the ETX680 and the ETX680C?
A: The only difference is physical size. Both batteries have identical electrical specs: 13.2V, 12.4 Ah, 680 Peak Cranking Amps, and 320 CCA. The ETX680C is the compact version, measuring 5.9" x 3.4" x 4.5" compared to the ETX680's 6.5" x 3.0" x 6.6". The ETX680C is also 0.2 lbs lighter and uses C-case accessories rather than E-case accessories. If both sizes fit your installation, either will perform identically.
Is the ETX680C compatible with my aircraft's charging system?
A: The ETX680C is designed for aircraft and vehicles with a charging system that produces 60 amps or less. It is compatible with most modern vehicle charging systems and standard lead-acid battery chargers. If your alternator output exceeds 60 amps, look at the ETX900 or ETX1200 series instead. Refer to the product manual for full electrical requirements before installing.
What is the black pigtail wire on the ETX680C?
A: The black pigtail wire is a fault indicator connector included with all ETX Hundred Series batteries. Connect it to a 12V LED indicator light (sold separately) on your instrument panel or to your EFIS. If the built-in BMS detects something outside the normal range — such as a low-voltage condition, a weak cell, or an overcharge event — the LED will alert you. Full wiring instructions and LED indicator meanings are in the product manual.
Do I need the terminal adapter for the ETX680C?
A: It depends on your aircraft's existing terminal configuration. Some installations require the Adapter-CDE terminal adapters to match the C, D, or E case terminal layout. If you're replacing a battery with different terminal positioning, the adapter kit is the easiest way to ensure a proper connection. We offer these as an add-on during checkout.
Which battery box is compatible with the ETX680C?
A: The ETX680C uses C-case battery boxes. The BB-TH-CO Thermal Battery Box is the FAA PMA-approved option and is available on our site. Note that E-case boxes designed for the ETX680 will not fit the ETX680C due to the different dimensions. Always verify the case size before purchasing a battery box.
Customer Reviews
The EarthX ETX680C was my choice for an aircraft application, but when I took the battery from the shipping box and rotated it in my hands, it went "thud" within it's own case. Something substantial was free to move inside the battery case, not withstanding the fact that the terminal voltage tested normal full charge. I contacted EarthX via their email portal and got a response within 30 minutes !! They shipped a replacement the same day. The new battery, without a "thud", was in my hands 2 days later, along with a prepaid return shipping label for the "thud" unit.
Customer service doesn't get any better than that.
I HAD ANOTHER (BRAND) LITHIUM BATTERY FOR 6 YEARS TIL IT DIED BUT IT NEVER TURNED THE ROTAX912S LIKE THIS EARTHX 680C DOES. LOOKS LIKE A GREAT BATTERY AND ESPECIALLY THE FACT THAT IT HAS AN INDICATOR LIGHT THAT GIVE ONE AN INDICATION OF BATTERY TROUBLE. I MOUNTED THE INDICATOR LIGHT IN A SPOT THAT I WILL NOT MISS IT IF SOMETHING DOES GO WRONG. I DON'T EXPECT A PROBLEM BUT IT'S NICE TO HAVE A BACK UP SYSTEM. TELL YOU HAW THINGS GO IN 8 YEARS WHICH IS THE POSSIBLE LIFE OF THE BATTERY.
I purchased the Earth X battery to replace 2 Odyssey batteries I had for my Lycoming O320. The battery arrived in very secure and padded box with in 7 days of order. The battery is extremely light and my weight went from 30Lbs down to 4Lbs! This has helped my weight and balance dramatically. The engine cranks over much faster than with 2 Odyssey batteries and the alternator refreshes the battery to full charge with in minutes of run time. The extra crank power is very noticeable. We will see how long this battery lasts but based on history from others, I expect much longer use than with a lead acid battery.
