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EarthX ETX680C

Flyingbeard

Active Member
Hi Everyone,

I have two ETX680C batteries installed on my RV-8. I purchased them off the EarthX website in April 2018. They have been sitting on the self until recently. I am just finishing my build and got my FAA sign off on the August 24th. I fully charged both batteries with OptiMate 5 amp Lithium charger and all seemed normal. I then ran the batteries down doing avionics checks and EFIS configuration. I plugged in the batteries one at a time to recharge. One battery recharged and seems normal, the other will not take a charge. I have tried to reset the BMS, by disconnecting the battery per the video on the EarthX website, but that is not working. The charger is going into save mode, but then starts flashing Red. Any ideas to charge the battery or is it toast?.:eek: I didn't plan on running the batteries so low, but got caught up working on the settings.

Any ideas? Thanks in advance.

Mark
 
Update 9-10-2020; I have to give credit where credit is due. EarthX absolutely deserves respect! I am abundantly relived and happy. I probably vented my frustration too early. I sent my batteries back to EarthX and they took care of the situation and me better than I deserve. I attest that they truly do care about us little homebuilt guys a great deal. Much respect. I work in Tech and in silicon valley, earthX is legit and deserves serious consideration. This is the future. Total honesty here.

orig. message: Wow, I share the same feeling on my ETX680C's, I made the mistake of buying these a year and a half ago, stored them in my house closet thinking that would be smart. Welp that was an 800 dollar bad decision. And that thread from Ross of that link above....that is compelling. You can't refute that. Makes my decision to remedy my trouble extremely clear.
Thanks for sharing this. I got bit bad by mine, but I think this all is saving future headache and frustration and saving a huge amount of money going ahead.
Thanks.
 
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Or hook up to a regular battery charger FOR A FEW MINUTES ONLY. I remember something about when the voltage gets too low, the BMS cuts the power, then the recommended charger will not charge because it doesn’t senes a battery connected. A traditional charger should wake it up, then switch to the recommended charger.
 
You might try hooking it up to a trickle charger like the Battery Tender Jr for a few hours. That might get the voltage up enough for your regular charger to work.

https://www.amazon.com/Battery-Tend...ocphy=1026991&hvtargid=pla-370669784302&psc=1

Be careful. Be sure you select a charger that is appropriate the EarthX's higher voltage. Battery Tender Jr trickle chargers are called out as suitable for EarthX batteries in their manual, but that's not quite true for other battery tenders. For it is written:

"The ETX Lithium battery is compatible with most “modern” lead-acid battery chargers or 4cell LiFePO4 battery chargers (8 cell for 24V replacement battery). By “modern” we mean a charger that automatically turns off when the battery is fully charged, a charger with a micro-processor, or a charger with multiple mode charging. The “full charge” voltage for the ETX Lithium battery is 13.9V or higher. Some lead-acid battery trickle charger’s
maintenance mode voltage can be below 13.3V, which is too low for a lithium battery. For example, the Battery Tender JR has a maintenance mode voltage of 13.3V which is compatible, whereas the original Battery Tender has a maintenance mode voltage of 13.2V which is too low for a lithium battery."

In any case, be sure you never use the de-sulfate setting on your charger.

BTW, did you get a steady or flashing fault indication from the battery fault LED?

If nothing else, I suggest you give Kathy a call at EarthX. They're hugely helpful.
 
Has anyone installed a set of battery charger leads for periods of inactivity?
 
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To echo what others have said most modern chargers won’t charge unless they sense some voltage in the battery you are attempting to charge. There are ways to defeat this that can be googled or I would call EarthX.
G
 
Call the manufacture??

As I recall, the total capacity is a lot shorter than a lead acid battery rated at the same amperage.

Ross did a good thread on this. https://vansairforce.net/community/showthread.php?t=178037

Traditional lead-acid and LiFePO4 batteries behave much differently and you can’t make a blanket statement that “total capacity is a lot shorter” without specifying which capacity.

What you have to keep in mind is that lead-acid batteries suffer a noticeable performance penalty as current draw goes up. A 10Ah lead-acid battery will give you 1 amp for 10 hours, but it won’t give you 5 amps for 2 hours (it’ll be somewhat less) or 10 amps for 1 hour (it’ll be even less). Extrapolate that out to starting current draws (in the hundreds of amps) and you’re using only a fraction of the theoretical capacity.

A LiFePO4 battery, OTOH, doesn’t suffer nearly as much of a penalty at high current draws. A (true, not lead-acid equivalent) 10Ah lithium battery will give you close to an hour at 10 amps.

So what does this mean? Well, it means you have to be very careful comparing the capacity of a lead-acid battery to a LiFePO4 one, and what capacity figure you care about depends on how you intend to use the battery.

For example, many of the “powersports”/non-aviation lithium batteries are rated by their “lead-acid equivalent” amp-hour rating. They’re intended for use as starting batteries—their primary job is to crank the vehicle they’re installed in, and they then get recharged by the vehicle’s alternator (just like your car). The ability of the battery to sustain operating loads (engine and accessories) is not a concern for the job they’re intended to do, and so they’re only sized for cranking ability. Since a LiFePO4 battery suffers less penalty at high current draws, a one of those sized just for cranking performance doesn’t need as much total capacity—it can use a lower capacity more efficiently.

If you’re sizing your battery for an aviation role, particularly one where you care about the ability of the battery to deliver some level of power over a given time period (for your avionics and/or electrically-dependent engine) you need to look at the actual usable capacity, not lead-acid equivalent. EarthX, at least, does a really good job of showing this in their product documentation; they actually provide graphs for their aviation batteries showing voltage vs. time at different discharge rates.

If you use this actual amp-hour figure from a LiFePO4 battery, you’ll find that it lasts longer at higher current draws than a lead-acid battery with the same amp-hour rating, and starting performance should be much better.


(full disclosure—I have chosen to go with EarthX for my electrically-dependent engine/aircraft; what I wrote above is a summary of my research into battery capacities while choosing a battery. I do not work for any battery supplier and I haven’t been paid to promote one; I mention EarthX above because, as an aircraft systems engineer, I appreciate the level of detail shown in their documentation which is leaps and bounds better than just one “capacity” number, equivalent or not)
 
Traditional lead-acid and LiFePO4 batteries behave much differently and you can’t make a blanket statement that “total capacity is a lot shorter” without specifying which capacity.

What you have to keep in mind is that lead-acid batteries suffer a noticeable performance penalty as current draw goes up. A 10Ah lead-acid battery will give you 1 amp for 10 hours, but it won’t give you 5 amps for 2 hours (it’ll be somewhat less) or 10 amps for 1 hour (it’ll be even less). Extrapolate that out to starting current draws (in the hundreds of amps) and you’re using only a fraction of the theoretical capacity.

A LiFePO4 battery, OTOH, doesn’t suffer nearly as much of a penalty at high current draws. A (true, not lead-acid equivalent) 10Ah lithium battery will give you close to an hour at 10 amps.

So what does this mean? Well, it means you have to be very careful comparing the capacity of a lead-acid battery to a LiFePO4 one, and what capacity figure you care about depends on how you intend to use the battery.

For example, many of the “powersports”/non-aviation lithium batteries are rated by their “lead-acid equivalent” amp-hour rating. They’re intended for use as starting batteries—their primary job is to crank the vehicle they’re installed in, and they then get recharged by the vehicle’s alternator (just like your car). The ability of the battery to sustain operating loads (engine and accessories) is not a concern for the job they’re intended to do, and so they’re only sized for cranking ability. Since a LiFePO4 battery suffers less penalty at high current draws, a one of those sized just for cranking performance doesn’t need as much total capacity—it can use a lower capacity more efficiently.

If you’re sizing your battery for an aviation role, particularly one where you care about the ability of the battery to deliver some level of power over a given time period (for your avionics and/or electrically-dependent engine) you need to look at the actual usable capacity, not lead-acid equivalent. EarthX, at least, does a really good job of showing this in their product documentation; they actually provide graphs for their aviation batteries showing voltage vs. time at different discharge rates.

If you use this actual amp-hour figure from a LiFePO4 battery, you’ll find that it lasts longer at higher current draws than a lead-acid battery with the same amp-hour rating, and starting performance should be much better.


(full disclosure—I have chosen to go with EarthX for my electrically-dependent engine/aircraft; what I wrote above is a summary of my research into battery capacities while choosing a battery. I do not work for any battery supplier and I haven’t been paid to promote one; I mention EarthX above because, as an aircraft systems engineer, I appreciate the level of detail shown in their documentation which is leaps and bounds better than just one “capacity” number, equivalent or not)

I have learned the same as you. Unfortunately there are VERY few lithium batt manufacturers that list actual A/hr or reserve capacity; They only publish PB equiv. This is why I didn't go that route. The Eathx stuff was just too expensive for my needs and I wanted a non-BMS batt.

Larry
 
Wow, Thanks for the quick replies overnight!

First off, I am going to call EarthX this morning and I will post what I find out. The Battery fault light is flashing red, the charger is a OptiMate 5 amp Lithium Battery Charger Model TM-291 with BMS reset. This Charger goes into save mode and then after a few minutes (the charger) starts flashing red.

FYI: I charged the good battery overnight and was able to use that battery for starting with no issues.

I will post again as soon as I talk with the people at EarthX.
 
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I had a similar experience - battery in save mode after a complete discharge. I called EarthX and was told to leave the battery on the EarthX recommended charger overnight. The following day, in the late afternoon, the battery was finally fully charged.
 
Some very good information - what I would put into the “required reading” bucket for builders planing their system design.

On “what will I really get for Amp-Hr capacity”, remember that documentation is just a start. Run all the panel loads you would have for IFR flight and time how long it takes for your buss voltage to go below your level of pain. Then decide if this meets your tolerance threshold. If not, work how you will mitigate it. For me I set 2+ hours of full panel IFR capability as the design requirement.

Side note - if you are going to great lengths to beat some life back into an abused battery (no matter what type) I suggest you bite the bullet and just replace it. I consider an abused battery too much of an unknown for my airplane.

Carl
 
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Update

Hi All and thanks for the replies. I spoke with Kathy from EarthX this morning, they are sending a shipping label to return the battery for repair or replacement.

Her customer service was great, she listened to my issue and worked to help me.

Just what you would expect from a vender on VAF.

I will update in a few weeks as I am flying for my day job till the 14th.
 
Battery charger connections

Has anyone installed a set of battery charger leads for periods of inactivity?

I installed a cigarette lighter plug for each of my batteries. Can use it to charge my batteries as well as plug accessories into.
 

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Has anyone installed a set of battery charger leads for periods of inactivity?

Yes. I have a set of leads wired to the battery in the oil door with the plug for their charger. Also made a cable that fits the charge plug (always hot, fused) with a cigarette plug on the other end. Can charge phones when camping, outside the plane with the master off.
 
Call EarthX. They worked with me to resolve a problem I had with the Battery Control Module. They were able to repair it for a nominal charge as my battery was also out of the 2 year warranty.
 
Yes. I have a set of leads wired to the battery in the oil door with the plug for their charger. Also made a cable that fits the charge plug (always hot, fused) with a cigarette plug on the other end. Can charge phones when camping, outside the plane with the master off.

When I got the battery charger from EarthX, it came with ring terminal leads and which has an idiot proof, water-tight capped plug on the other end. That plug connects to the one on the charger. I leave that on the battery and pop the hatch and charge as needed. Saves a lot of pain compared to the big alligator clips.
 
I installed a cigarette lighter plug for each of my batteries. Can use it to charge my batteries as well as plug accessories into.

I tried this, but changed for a more purpose plug. The problem is that with the charger, the tip of the plug is hot (vs non powered for an accessory). When I inserted the plug with the charger plugged in, I too often grazed the inside of the receptacle with the powered tip. Blown fuse.
 
Charger Leads Built In

Has anyone installed a set of battery charger leads for periods of inactivity?

Yes, I have a pigtail on my battery and have it plugged into the charger all the time. Never a problem in several years in my Sonex, now in the RV9A
Ed
 
Several of the battery companies selling to auto/powersports list their capacities as Pb/equivalent. The actual capacity is less, by as much as 2/3. Reading EarthX's stuff makes me think their capacity is actual Ah rating, and listed as a "1C" rate, which means pulling the battery down in 1 hour.

Also the weight of the EarthX vs the "others" makes me also think the EarthX is actual AH capacity.
 
The Earth X battery has some good features but the control board on their battery is not one of them. Had one fail on me. Because I was AOG and could not wait for the battery to be repaired, for a cost, I ended up installing a Odyssey battery to get home. Earth X should offer an extended coverage on their circuit board since there have been failures with it.
 
I am aware of this and take care when inserting. To be honest, I have not used the charging option in over a year. I fly at least once per week and the batteries never need the additional charging.
 
Battery Update

Hi Everyone,

I have been traveling for work, but I got my battery sent back to EarthX. They evaluated it and found a cell that was drained below it’s minimum voltage (9V). When this happens it becomes damaged and will not accept a charge anymore.

So, the battery was damaged and out of warranty. EarthX offered me a new or refurbished replacement battery at a discount. I chose the new battery as it came with a 2 year warranty.

Thanks to Kathy at EarthX for going the extra mile and helping me out. The new battery will be waiting for me when I get back to the airplane.
 
Hi Everyone,

I have been traveling for work, but I got my battery sent back to EarthX. They evaluated it and found a cell that was drained below it’s minimum voltage (9V). When this happens it becomes damaged and will not accept a charge anymore.

So, the battery was damaged and out of warranty. EarthX offered me a new or refurbished replacement battery at a discount. I chose the new battery as it came with a 2 year warranty.

Thanks to Kathy at EarthX for going the extra mile and helping me out. The new battery will be waiting for me when I get back to the airplane.

Dear Mark,

It was a pleasure to work with you and I am glad you are pleased. EarthX does strive to provide excellent customer service and support and we do truly appreciate your business!
This is NOT directed to you or your specific situation, but this might be a good thread to post some “GOLDEN RULES” about batteries, lead acid or lithium.

1. All batteries will fail at some point. They do not have infinite life spans no matter how awesome you take care of them or how much you spend.
2. All products can have a manufacturing defect. It is impossible to have a 0% failure rate. Typically, a manufacturing defect will occur much sooner than later.
3. All batteries will lose their charge (voltage) with time. There is no battery chemistry invented where this does not apply. Either your vehicles charging system will charge the battery when in use, or you must use a charger. Even if the battery is “new in the box” where you have stored it for years. Time does not stop and the aging process continues.
4. All batteries will be permanently damaged if left in a discharged state, the amount of damage depends on the depth of discharge and how long it remained in this state (<9 volts for LiFePo4).
5. Lead acid batteries are more susceptible to freezing and once frozen, will be permanently damaged.
6. Using an undersized battery (capacity and/or cranking) will shorten a batteries life and can cause damage.
7. Using and storing a battery in excessive heat, will shorten a batteries life. (The manufacturer should have this listed what their temperate range is)

The battery is a very important component in your vehicles charging system. Read the warnings and manual of whatever battery you choose to properly maintain it to avoid frustrating and avoidable failures.
 
Kathy,
since traditional batteries do not have circuit boards that can fail, but the EarthX batteries do, don’t you think there should be some additional coverage on the battery circuit board.
 
Thank you for the question. EarthX does offer a 2 year full coverage warranty. The nature of all electronic component failures, it will either fail very early in life (certainly within the 2 year coverage time frame) or in this application, long after the cells have outlived their useful life. (Called the “bathtub effect”). This is very rare to have an electronic component failure but in the event there is one, the aircraft designed batteries will illuminate a solid LED alert, which is not a single point of failure as the BMS circuit board is redundant for backup protection.
 
I have to give credit where credit is due. EarthX absolutely deserves respect! I am abundantly relieved and happy with the lipo batteries I invested in. I had an issue but because I hastily bought my batteries a year ago and stuck them in my home closet. Had an issue last month when I opened them. I sent my batteries back to EarthX and they took care of the situation better than I deserve I am guessing. I attest that they truly do care about us little homebuilt guys a great deal. Much respect. I work in Tech industry as an engineer in silicon valley at the big one, and earthX is legit and deserves serious consideration. Its a fact this technology is the future. Total honesty here.
 
You are very welcome!

I have to give credit where credit is due. EarthX absolutely deserves respect! I am abundantly relieved and happy with the lipo batteries I invested in. I had an issue but because I hastily bought my batteries a year ago and stuck them in my home closet. Had an issue last month when I opened them. I sent my batteries back to EarthX and they took care of the situation better than I deserve I am guessing. I attest that they truly do care about us little homebuilt guys a great deal. Much respect. I work in Tech industry as an engineer in silicon valley at the big one, and earthX is legit and deserves serious consideration. Its a fact this technology is the future. Total honesty here.

Thank you! We are very pleased to be able to provide you service above and beyond your expectations.
 
The Earth X battery has some good features but the control board on their battery is not one of them. Had one fail on me. Because I was AOG and could not wait for the battery to be repaired, for a cost, I ended up installing a Odyssey battery to get home. Earth X should offer an extended coverage on their circuit board since there have been failures with it.


I too had my EarthX fail early in its life. I was not AOG but at my Hangar. Turned on the master and received power from the battery for a split second, then I heard a clunk from the battery and it stopped producing any power. The light on the battery illuminated. This got me thinking about batteries with their own brain internally (aka BMS System). If I am in the back country or on a gravel bar and the BMS senses a fault, then there I sit.

This was back in 2017. Maybe Kathy could comment on any improvements done to the battery/BMS since then.

I sent this battery back to Kathy at the time of the incident and she sent me a new battery promptly. I received great service from EarthX.
 
Hello Jim,
EarthX is committed to investing in R & D and being at the forefront of lithium battery technology, not only in aircraft, but many other markets too. As technology advances, so does the EarthX batteries. Some of the components we use today in our battery management system were not even in existence just a few years back. We have worked closely with many aircraft manufacturers and engine manufacturers over the years with shared intellect to produce batteries that are designed around the requirements needed to have an optimal pairing of battery with charging system/engine. Having a BMS that can alert you to something outside of normal (fault) is just one of the great advancements.
 
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