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Earthx battery experiences

RVDan

RVDan

Well Known Member
Patron
Earthx seems to have provided a cost effective, lightweight and safe product for our experimental airplanes. They have now had batteries in the experimental market for several years. I was wondering if anyone has experienced a venting of the battery, either in the cockpit or not. That is a key safety element for me.

I want to get rid of my Concord boat anchor that I have to replace every 3-4 years. If others have good or bad experiences otherwise, I’d be interested in hearing.
 
I’ve had an EarthX for a couple of years now. I’ve had zero problems with it.
It was a great upgrade from the PC680. The PC680 would not completely turn over my IO350 on the first try. The EarthX has no such problems. Plenty of cranking power.
 
5+ years on EarthX, both ETX680 and ETX900, firewall mounted with blast tube cooling. ZERO issues, spectacular batteries.
 
Earth X for 2.5 years LOVE IT

Cranks like crazy, I haven't had a single issue. I was concerned about the ambient temp, because it on the front of the fire wall, but again no issues seen. I do open my oil door after landing just to help cool things down, but I know other who don't.

and by the way, when you get it, it will be so light that it feels like an empty case!

enjoy!
 
Excellent

I'm very happy with the EarthX ETX680 in my RV-7. (knocking wood). Firewall mounted with the aluminum case. I leave the oil door open after shutdown to keep things cool.

The one caution I would offer is to make sure that whatever size battery you get matches the alternator's output capability.

I encountered this while using an ETX900 with 60A alternator. A bad hot start
+ discharged battery and I could see >80A once I started the engine and flipped on the alternator.
 
bjdecker said:
I'm very happy with the EarthX ETX680 in my RV-7. (knocking wood). Firewall mounted with the aluminum case. I leave the oil door open after shutdown to keep things cool.

The one caution I would offer is to make sure that whatever size battery you get matches the alternator's output capability.

I encountered this while using an ETX900 with 60A alternator. A bad hot start
+ discharged battery and I could see >80A once I started the engine and flipped on the alternator.
Click to expand...

For a 60 amp alternator, get the ETX 680.
For a 70 amp alternator, get the ETX 900.

When in doubt, call Kathy or any of the crew at EarthX and ask them which battery to buy for your particular alternator.
 
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Great batteries !!

bjdecker said:
I'm very happy with the EarthX ETX680 in my RV-7. (knocking wood). Firewall mounted with the aluminum case. I leave the oil door open after shutdown to keep things cool.

The one caution I would offer is to make sure that whatever size battery you get matches the alternator's output capability.

I encountered this while using an ETX900 with 60A alternator. A bad hot start
+ discharged battery and I could see >80A once I started the engine and flipped on the alternator.
Click to expand...

The ETX 680 is rated at:
Max Charge Amps
60A (from vehicle charging system)

The issue is a 60 amp alternator will output 70 amps(At least a B&C) will and even though when your battery is low only for a few minutes but still exceeds the recommended limit. I am using 2 ETX-900’s which are rated at 80 amp max. Gives a little more ampacity at a very modest weight increase over the 680 plus it gives you more reserve capacity. (680, 900 and 1200 all have the same size case). 4 years flying and 6 years total and never an issue. Test annually to insure I have at least 80% ampacity left.
 
I have two ETX-900 batteries mounted on the firewall of my RV-10 and have been very happy with them. When I bought the plane about 18 months ago, I had some battery overheating issues in very hot conditions. Once I added some blast cooling with diverted air from a scat tube, that problem was fixed.

Just make sure that you follow the installation recommendations regarding having a BMS and ensuring that it gets vented to the outside.
 
Hi Dan,
I've had an EarthX in my Velocity for about 5 years now with no issues. I live in the same climate as you do (based at KCJR, hangared). I have a IO360 200Hp and the battery is way up in the pointy end (about 15' of #2 cable). As with the lead-acid battery, the first button push results in just a click (accompanied by look of shock on passengers). I was told by the local A&P that this version of the 360 had this issue in the planes in which it was installed. The second push is normal start, summer and winter.

I hardly ever put it on the charger, unless I've had the avionics on for a while. It still powers up with 13+ volts. I did a time test last year during the CI and it lasted well beyond my amp-hour calculation (with 2 Garmin screens, GTN 650, Garmin 200 + transponder....). You also have to invest in a special charger for the battery. So figure that into the cost.

I went from a 35# lead-acid to a 4# LiFePo4 ... put me right at the aft limit when I'm in the plane. The plane flies much nicer now. Make sure you don't get out of your CG envelope.

MTCW,
db
 
Ezburton said:
Make sure you don't get out of your CG envelope.
Click to expand...

EZB does raise a good point, Dan. If you're flying a 6A and want to mount the EarthX on the firewall (typical mount), you'll want to pay close attention to your aft CG. Mine did move way aft (10 lbs lighter at the firewall).

I addressed this by melting down lead tire weights to mold a battery box-shaped lead ingot. 10 lbs of lead under the EarthX battery returned the CG forward to a point acceptable with a full baggage load. I did check with the EarthX engineers to be sure their stainless steel thermal battery box can handle the higher weight under G (it can indeed, up to over 250 lbs).

Meaning, yes, I lost the lighter weight benefit but still thoroughly enjoying the high power/long amp hour benefit.
 
One more data point

I have a ETX900 VNT under the rear baggage floor, vented outside.
I also have a ETX680 in an insulated box on the firewall, engine side.
The 680 has a fresh air blast tube (blocked off in winter)
Installed since 2020, flying since Nov. 2021.
Fantastic starting
Just over 9 lb for both
Absolutely no issues
Absolutely happy with these.
 

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Almost all of our team now is running them with no issues, along with several customers. The only complaint I have ever had is someone who shorted it out via a wrench, the electronics turned the battery off, and earth X replaced it for us even though it was the user error not a battery issue.

I hated to spend the money, but they are worth it.
 
Have a dissenting opinion. Was a very early adopter of the Lithium battery.

Unfortunately, despite claims it would be OK in storage, mine lost all charge sitting on the shelf while I finished the plane.

This was in Jay Pratt's hangar, so not out in the sun or anything. The battery swelled and wouldn't take a charge per their instructions. I didn't get anything from contacting them on warranty (had just expired) other than a nominal discount for a future purchase. To me for the price the juice isn't worth the squeeze when a regular battery can use any charger and started the plane just fine.

With that said, it seems like a great battery on paper, but unnecessary for an RV. The extra ampacity and weight savings would help me with another plane that's firewall heavy.
 
NTex said:
Have a dissenting opinion. Was a very early adopter of the Lithium battery.

Unfortunately, despite claims it would be OK in storage, mine lost all charge sitting on the shelf while I finished the plane.

This was in Jay Pratt's hangar, so not out in the sun or anything. The battery swelled and wouldn't take a charge per their instructions. I didn't get anything from contacting them on warranty (had just expired) other than a nominal discount for a future purchase. To me for the price the juice isn't worth the squeeze when a regular battery can use any charger and started the plane just fine.

With that said, it seems like a great battery on paper, but unnecessary for an RV. The extra ampacity and weight savings would help me with another plane that's firewall heavy.
Click to expand...

Just curious ... was it an EarthX or another brand? Li-Poly? Li-Ion? Li-FE?

Also, what year were you an early adopter?

Battery management circuitry varies greatly among these brands.

Regarding a "puffed" lithium battery to anyone reading ... discard immediately and don't use, something has gone horribly wrong.
 
bkervaski said:
Regarding a "puffed" lithium battery to anyone reading ... discard immediately and don't use, something has gone horribly wrong.
Click to expand...

BV's right: Don't use, but please don't discard. EarthX will be interested in discovering why it expanded: They'll want it back, and will possibly pay shipping to return it for analysis. Bottom line: Call them to discuss.
 
NTex said:
Have a dissenting opinion. Was a very early adopter of the Lithium battery.

Unfortunately, despite claims it would be OK in storage, mine lost all charge sitting on the shelf while I finished the plane.

This was in Jay Pratt's hangar, so not out in the sun or anything. The battery swelled and wouldn't take a charge per their instructions. I didn't get anything from contacting them on warranty (had just expired) other than a nominal discount for a future purchase. To me for the price the juice isn't worth the squeeze when a regular battery can use any charger and started the plane just fine.

With that said, it seems like a great battery on paper, but unnecessary for an RV. The extra ampacity and weight savings would help me with another plane that's firewall heavy.
Click to expand...

While lithium batteries should last much longer in the shelf, they are still subject to discharge; it is just much less than a standard lead acid battery. Given enough time without a charge, yes they will go dead and may not be recoverable.
 
Regarding a non-puffed dead lithium battery ... there's a trick that works very well ... while monitoring the voltage closely, use a 1A standard wall wart charger to milk the battery up to the voltage that your approved battery maintainer requires to balance the cells and complete the charge.
 
NTex said:
Have a dissenting opinion. Was a very early adopter of the Lithium battery.

Unfortunately, despite claims it would be OK in storage, mine lost all charge sitting on the shelf while I finished the plane.

This was in Jay Pratt's hangar, so not out in the sun or anything. The battery swelled and wouldn't take a charge per their instructions. I didn't get anything from contacting them on warranty (had just expired) other than a nominal discount for a future purchase. To me for the price the juice isn't worth the squeeze when a regular battery can use any charger and started the plane just fine.
.
Click to expand...

Had a similar experience, except when I put the battery on a reg 8 amp charger to try to ‘jump start’ it (sat for approx 6 months and was 0 volts) it proceeded to melt onto my hanger floor in short order.
When I contacted EX, they basically said to bad so sad.
 
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Reg charger?

Walt said:
Had a similar experience, except when I put the battery on a reg 8 amp charger to try to ‘jump start’ it (sat for approx 6 months and was 0 volts) it proceeded to melt onto my hanger floor in short order.
When I contacted EX, they basically said to bad so sad.
Click to expand...

You used a regular charger on a lithium battery?
 
rocketman1988 said:
You used a regular charger on a lithium battery?
Click to expand...

Yep, figured nothing to lose, it also toasted my cherished old school charger as well :eek:
Actually not sure which gave up first, but suspect the charger gave its life to save me.
Not much difference between an old school charger and an alternator IMO (alternators are not ‘special’ either).
I suspect an alternator with much higher output might have been a real problem if the bat had been in the plane.
 
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bkervaski said:
Regarding a "puffed" lithium battery to anyone reading ... discard immediately and don't use, something has gone horribly wrong.
Click to expand...

I had a lithium battery in my laptop that puffed up and it happens all the time in Apple laptops. No need to stop using it. I used it for many years after that but just got a couple of hours before having to plug it in again versus the 12 hours with a good battery.

I believe the problem is when someone uses a cheap charger on any battery and even worse on a lithium battery. Some chargers use high voltage and low current while others use lower voltage and high current. The best chargers monitor and change the voltage and current values based on battery temperature and charge level.
 
bkervaski said:
Just curious ... was it an EarthX or another brand? Li-Poly? Li-Ion? Li-FE?

Also, what year were you an early adopter?

Battery management circuitry varies greatly among these brands.

Regarding a "puffed" lithium battery to anyone reading ... discard immediately and don't use, something has gone horribly wrong.
Click to expand...


This was an ETX36C purchased for $349 in 2014.

It had all the "BMS" but apparently didn't work for me, it didn't 'puff' more than a few degrees but you could certainly tell the blue casing was no longer 90 degrees in the midsections.

>>Moderator edit: No defamatory language, please.<<
 
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If you use an E-Mag, make darn sure you have either a backup alternator, or a stand-by battery (both are preferred for IFR flying). Once the battery discharges to below 11V, the BMS system will shut the battery off. Happened to me last week over mountainous terrain. Lost all avionics and my Surefly E-Mag. Mine was self-inflicted as I had not turned on the field switch on the split master. ...in all my years of flying, that's the only time I missed that. Good thing it was the middle of the day in "severe clear"...right over the top of Penn Valley airport!

Once I charged up over 11 volts, Engine started right up and I was good to go.
Talk about clench your cheeks when that happens!
 
BMS cut-off

mikelupo said:
If you use an E-Mag, make darn sure you have either a backup alternator, or a stand-by battery (both are preferred for IFR flying). Once the battery discharges to below 11V, the BMS system will shut the battery off. Happened to me last week over mountainous terrain. Lost all avionics and my Surefly E-Mag. Mine was self-inflicted as I had not turned on the field switch on the split master. ...in all my years of flying, that's the only time I missed that. Good thing it was the middle of the day in "severe clear"...right over the top of Penn Valley airport!

Once I charged up over 11 volts, Engine started right up and I was good to go.
Talk about clench your cheeks when that happens!
Click to expand...

Earth X will state once the BMS is activated you would have had less than a minute before the battery falls to a state probably unusable. (Less than 9 volts).

Would advise that everyone sets a voltage alarm (yellow) status at 13.4 volts and a red status at 12.8 volts. Plus having a shunt or Hall effect sensor (amperage sensor) on your b lead to detect when either alternator fails, field left off or fuse opens, etc. Normal operating voltage should read in the 14.2 volt range. Also the use of the battery warning light (supplied by Earth-X) should be used. That will give you low voltage alarm or an overheated battery alarm.

Warning: The chemistry that Earth X uses will show a very flat line discharge voltage rate for the first 90% of a discharge. The last 10% the voltage will drop very quickly !! Best practice is to discharge the battery 80% to insure it still has 12 volts with a 5 amp discharge. Use a very inexpensive Amp Hour totalizator (found on Amazon for less than 20 bucks) to check the ampacity of the battery as rated. I do this every condition inspection. For an energy dependent engine the feeling is “priceless”.

Earth-X will last 5 to 6 years if not abused.

Safe travels!!
 
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mikelupo said:
...in all my years of flying, that's the only time I missed that. !
Click to expand...

Best advertisement for using a checklist !! It's not IF, it's WHEN. I'm to a point that I even added to my checklist to turn on the camera before getting into the plane because I hate having to get out after being strapped in because I forgot something I do every time, yet sometimes I forget.
 
Also a good advertisement for installing a surefly IAW the manufacturer’s detailed and specific instructions. They are STCd for many certified airframes after all.
Installed such, I find it very difficult to see how one could find themselves in this situation. There should be many layers of redundancy to prevent an electrically dependent aircraft to fly for an extended period at the mercy of an undetected charging system fault.
I would imagine this install is non compliant. Perhaps in more than one way.
Definitely worth checking out.
 
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RVDan said:
Earthx seems to have provided a cost effective, lightweight and safe product for our experimental airplanes. They have now had batteries in the experimental market for several years. I was wondering if anyone has experienced a venting of the battery, either in the cockpit or not. That is a key safety element for me.

I want to get rid of my Concord boat anchor that I have to replace every 3-4 years. If others have good or bad experiences otherwise, I’d be interested in hearing.
Click to expand...

If you’re replacing your Concorde every 3-4 years — assuming you’re talking AGM — you’re either mistreating it or there’s something wrong with your electrical system. You might oughta look into that before spending on an EarthX.
 
StuBob said:
If you’re replacing your Concorde every 3-4 years — assuming you’re talking AGM — you’re either mistreating it or there’s something wrong with your electrical system. You might oughta look into that before spending on an EarthX.
Click to expand...

AGM. Concord claims an expected life of 3 years. I have had them last 5 years , but in the last few years, they haven’t been that good.
I use the Concord approved charger and my aircraft electrical system voltage is very stable at 14.3 volts. When I talked to Concord about a battery that failed in 13 months, they blamed it on short flights and recommended leaving the charger on between flights. I do that, but it hasn’t made any difference.
 
*shrug*
That doesn’t match my experience or the general internet gestalt. Sorry they haven’t worked for you.

I’ve also had nothing but good experience with Odyssey, in a motorcycle and an airplane. Perhaps I’m an outlier.
 
StuBob said:
*shrug*
That doesn’t match my experience or the general internet gestalt. Sorry they haven’t worked for you.

I’ve also had nothing but good experience with Odyssey, in a motorcycle and an airplane. Perhaps I’m an outlier.
Click to expand...
I had reasonable experience with Odysseys, generally they'd be good for 5-6 years before getting weak but not failing (well one early failure out of four that I've owned, quickly replaced under warranty).

I don't expect a lot more from the EarthX but I've switched for the lighter weight, cranking power, and BMS feature. I'm only on my first one (ETX680), 4 years and so far so good.
 
How to get an early warning if your battery is beginning to fail:

Recently an owner/friend was a little frustrated as his battery gave up during a hot start gone bad. (ETX-680~4 yrs. old) I politely told him about the procedure I use to better understand my battery condition. Currently I test one battery every 6 months during an oil change and log it. I'm using 2 Earth-X batteries ETX-900 so rated at 15.6-amp hours each. My procedure is to discharge a battery down to ~ 12 volts. I have found for the Earth-X chemistry that at 12 volts the voltage begins to drop off pretty quickly. As long as the battery gives me more than 80% of its rated capacity (15.6-amp hours for an ETX-900) I'm good to go for another year. Of course, if I have an "event" that stresses my battery before the year next oil change, I check the ampacity again. Below is the logging device I use, and the inverter used to apply a load. If you have a 12 volt load greater than 7.5 amps that works but easier for me to use a 75-watt light bulb on a work light at 120 volts. This is also a good time to test the Earth-X low voltage warning light and EFIS alarms. This battery tested is 4.5 years on the airframe and 6.5 years since I received it.

 

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