EarthX Lithium batteries received FAA STC approvals for 150+ more 12V Aircraft!
The following 12V models were approved:
Alon A-2, A-2A
Bellanca 14-19, 14-19-2, 14-19-3, 14-19-3A, 17-30, 17-31, 17-31TC, 17-30A, 17-31A, 17-31ATC
Cessna 150D, 150E, 150F, 150G, 150H, 150J, 150K, A150K, 150L, A150L, 150M, A150M, 170, 170A, 170B,190, (LC-126A, B, C) 195, 195A, 195B, 206, U206, P206, U206A, P206A, TU206A, TU206B, TP206A, TP206B, U206B, P206C, P206D, TP206C, TP206D, TP206E, U-206C, U206D, U206E, U206F, TU206C, TU206D, TU206E, TU206F, U206G, TU206G, 210, 210A, 210B, 210C, 210D, 210-5 (205), 210-5A (205A), 210E, 210F, T210F, 210G, T210G, T210H, 210H, 210J, T210J, 210K, T210K
Ercoupe 415-C, 415-CD, 415-D, E, G
Extra Flugzeugproduktions EA 300, EA 300/S, EA 300/L, EA 300/200, EA 300/LC
Extra Aerobatic EXTRA NG
Forney F-1, F-1A
Gamebird GB1
Maule Bee Dee M-4, M-4, M-4C, M-4S, M-4T, M-4-180C, M-4-180S, M-4-180T, M-4-210, M-4-210C, M-4-210S, M-4-210T, M-4-220, M-4-220C, M-4-220S, M-4-220T, M-5-180C, M-5-200, M-5-210C, M-5-210TC, M-5-220C, M-5-235C, M-6-180, M-6-235, M-7-235, MX-7-235, MX-7-180, MXT-7-180, M-8-235, MX-7-160, MXT-7-160, MX-7-180A, MXT-7-180A, MX-7-180B, M-7-235B, M-7-235A, M-7-235C, MX-7-180C, M-7-260, M-7-260C, MX-7-160C, MX-7-180AC, M-4-180V, M-9-235
Mooney M10
Piper J3C-40, J3C-50, J3C-50S, J3C-65, J3C-65S, PA-11, PA-11S, PA-16, PA-16S
Stinson 108, 108-1, 108-2, 108-3, 108-5
Taylorcraft 15A, 19, 20, F19, F21, F21A, F21B, F22, F22A, F22B, F22C

No 180/185 STC?

MW

185Midwest wrote: No 180/185 STC? MW

Check page 3
https://earthxbatteries.com/wp-content/ ... _Final.pdf

Thanks

That's what I thought but it's not on the exhaustive list provided. Is the new battery box approved as of yet?

MW

Hello!
This list provided were new STC's we just got!

We already had the 12V 180 A-K and 12V 185 A-F STC's! You can see all approved models here: https://earthxbatteries.com/list-of-stcs/

Each airframe has an approved STC installation kit that goes with it. Some kits include a battery box and/or foam spacers!

Let us know if you have any other questions.

Does anyone know how the EarthX battery will store over the winter in -40 to -60F temps? Will it kill the battery like with lithium-ion? I'm interested in this for my Stinson, but there is a possibility of it wintering over in my place in rural Alaska.

Christina Young wrote:Does anyone know how the EarthX battery will store over the winter in -40 to -60F temps? Will it kill the battery like with lithium-ion? I'm interested in this for my Stinson, but there is a possibility of it wintering over in my place in rural Alaska.

Way better than any lead acid but you need to run some current through once it’s -10f or so, landing lights etc that warms up the battery internally. And don’t worry it’s not gonna drain the top charge off the battery. In fact if you miss the start the first time you don’t have to cross your fingers and pray like you did with the boat anchors, about the third try she will spin so fast you will blow the prime right out of the cylinders. Not kidding!

I never tried to fly or start below -30f myself and my pa-22 battery box was in the stock under seat location that didn’t get preheat. Sky tech NL starter and new cables throughout.

This was back when alaskans were first using the EX 36D PCA:680 12.4Ah motorcycle snowmachine battery, under the radar as it were.

My plane spent all winter skied up on the 5NK pond pit west without issue and later at the Talk village strip for a few more years where it got significantly colder.

Once I figured out to turn on the lights for a few minutes to wake up the battery chemistry I hadn't an issue one and last I heard that battery was still in service, gotta be ten years now if not more. Ok looks like it was twelve years. Went over to the SC.org and looked up a post I had made and gonna repost it here:


Dec 26, 2013

#47
Second report after my first couple weeks using the earthX ETX36D in Alaskan winter ski plane ops.


I made a up a nice set of cables to install the battery in my stock piper 1961 gill 35 sized box but it turned out I did not need them. A few years ago I had replaced the original corroded battery connectors with NOS ones from Unavair; basically a coper web strap with a stud penetrating the box. The reason I mention this is it turned out factory cables were a perfect fit onto the 36D mountings and I did not need the cables I had fabricated. The web materiel is very flexible and this will keep the stress in the battery terminal to a minimum; a posable problem area with this battery.


The first cold weather start with the battery it was 7 deg F but I had not preheated the engine as well as I would normally. The first two starts the prop turned over slowly about four blades each start. I didn't know I had under primed her so I spent the next five minutes I cranking her around and it was really spinning the prop fast. I was wondering if she was over driving the impulse coupling. I then spun the starter about three lead acid batteries worth. No ****! Now that the battery had warmed up internally it was putting out the amps for all it was worth. I have the Skytech in line something NL starter. I was just sitting there wondering when the battery would run out of juice when I said to myself, I do not smell any fuel??? She is not flooded. I pushed in eight strokes of my short primer, pushed the starter button, then she popped into life! I figure the prop was spinning so fast it had cleared the prime before wanting to fire. Hard to say with all the other variables.


The next real cold start it had been -7 degF, the first time I pushed the engine starter button the starter just buzzed, the prop would not pull through a compression stroke; three times in a row. Hmmm? I sat there a moment scratching my head. I turned on the lights, all LED, and radioes to get some current flowing through the battery to warm it up; SOP for lithium iron batteries in the arctic. The next time I pushed the button she spun all the way around slowly and then the engine caught. My girl usually fires, in the winter if well warmed and properly primed, on the third blade with the strong arm. After warm up and short taxi to fuel, sitting uncovered, say fifteen minutes, she hot starts with full throttle and the starter sinning the prop fast.


A couple more cold morning starts and the same thing, barely turning around, or not, at first but then spinning the prop around like the plugs were out! I am not sure I like it and am not sure how this low speed stall of the starter motor will affect the starter itself. Could it be arcing/cooking the commutator? Usually when it gets below zero I hand prop the first start of the morning anyway out of habit because of the old starters and their hanging bendex, you know, if one misses the start miss priming or whatever.


After the first start I mention above, where I spun and spun and spun the engine, I noticed the ammeter showing a solid plus 30 amps! After taking off I like to make a climbing turn around the pond in the winter just to make sure everything is warming up and working properly. It took about four minutes for the ammeter to drop to 20 amps where it stayed for about ten minutes more which was when I started having to aviat, talk to tower, and stopped looking at gage. I noticed after a handful of takeoffs that she was showing 20 amps and then the one time I could stare at the gage it just stayed charging at 20 amps for about 10-15 minutes then quickly dropped to < 1 amp. I have an older InterAv alternator which has worked flawlessly for years but wonder how asking it to kick out 20-30 amps or more is going to affect its longevity? I was thinking a generator or one of those light weight alternators might get cooked trying to actually crank out thirty amps for more then a moment.


I really only have about fifteen battery starts on the battery right now. My bird lives outside all winter up here in western Alaska were I will fly if the temperature is down to -20 degF. the battery will be exposed to -40 degF. I am thinking I should keep a new Gill-35 on the shelf just in case but will keep using the earthX battery because I think in the long run it has the potential to be a big improvement. Time will tell.

Ok, not so short.

Rocket

I've never been so excited for my battery to bite the dust, looking forward to upgrading when that happens.

I have a battery minder set up on my Concorde battery. Can that be used on the EarthX also? Or is there an equivalent?

Rocket, I know for a fact that an AGM battery will store just fine at -40 to -60F, as long as it's fully charged going in. The Odyssey in my cub has no problem starting up again if it is stored over the winter in such temps. I know for a fact the lithium ion batteries won't (this is why everyone has AGM or even better silicon salt batteries for off-grid systems in this area). I'm trying to find out if lithium iron phosphate is any better, but I can't seem to get a straight answer.

If you have a Gill waiting on the shelf (per you post below), do you really have complete confidence in the EarthX in extremely low storage temps down to -60F?

Unfortunately the Odyssey was never STC'd for the Stinson, so the only lightweight option I have is an EarthX.

rocket wrote:

Christina Young wrote:Does anyone know how the EarthX battery will store over the winter in -40 to -60F temps? Will it kill the battery like with lithium-ion? I'm interested in this for my Stinson, but there is a possibility of it wintering over in my place in rural Alaska.

Way better than any lead acid but you need to run some current through once it’s -10f or so, landing lights etc that warms up the battery internally. And don’t worry it’s not gonna drain the top charge off the battery. In fact if you miss the start the first time you don’t have to cross your fingers and pray like you did with the boat anchors, about the third try she will spin so fast you will blow the prime right out of the cylinders. Not kidding!

I never tried to fly or start below -30f myself and my pa-22 battery box was in the stock under seat location that didn’t get preheat. Sky tech NL starter and new cables throughout.

This was back when alaskans were first using the EX 36D PCA:680 12.4Ah motorcycle snowmachine battery, under the radar as it were.

My plane spent all winter skied up on the 5NK pond pit west without issue and later at the Talk village strip for a few more years where it got significantly colder.

Once I figured out to turn on the lights for a few minutes to wake up the battery chemistry I hadn't an issue one and last I heard that battery was still in service, gotta be ten years now if not more. Ok looks like it was twelve years. Went over to the SC.org and looked up a post I had made and gonna repost it here:


Dec 26, 2013

#47
Second report after my first couple weeks using the earthX ETX36D in Alaskan winter ski plane ops.


I made a up a nice set of cables to install the battery in my stock piper 1961 gill 35 sized box but it turned out I did not need them. A few years ago I had replaced the original corroded battery connectors with NOS ones from Unavair; basically a coper web strap with a stud penetrating the box. The reason I mention this is it turned out factory cables were a perfect fit onto the 36D mountings and I did not need the cables I had fabricated. The web materiel is very flexible and this will keep the stress in the battery terminal to a minimum; a posable problem area with this battery.


The first cold weather start with the battery it was 7 deg F but I had not preheated the engine as well as I would normally. The first two starts the prop turned over slowly about four blades each start. I didn't know I had under primed her so I spent the next five minutes I cranking her around and it was really spinning the prop fast. I was wondering if she was over driving the impulse coupling. I then spun the starter about three lead acid batteries worth. No ****! Now that the battery had warmed up internally it was putting out the amps for all it was worth. I have the Skytech in line something NL starter. I was just sitting there wondering when the battery would run out of juice when I said to myself, I do not smell any fuel??? She is not flooded. I pushed in eight strokes of my short primer, pushed the starter button, then she popped into life! I figure the prop was spinning so fast it had cleared the prime before wanting to fire. Hard to say with all the other variables.


The next real cold start it had been -7 degF, the first time I pushed the engine starter button the starter just buzzed, the prop would not pull through a compression stroke; three times in a row. Hmmm? I sat there a moment scratching my head. I turned on the lights, all LED, and radioes to get some current flowing through the battery to warm it up; SOP for lithium iron batteries in the arctic. The next time I pushed the button she spun all the way around slowly and then the engine caught. My girl usually fires, in the winter if well warmed and properly primed, on the third blade with the strong arm. After warm up and short taxi to fuel, sitting uncovered, say fifteen minutes, she hot starts with full throttle and the starter sinning the prop fast.


A couple more cold morning starts and the same thing, barely turning around, or not, at first but then spinning the prop around like the plugs were out! I am not sure I like it and am not sure how this low speed stall of the starter motor will affect the starter itself. Could it be arcing/cooking the commutator? Usually when it gets below zero I hand prop the first start of the morning anyway out of habit because of the old starters and their hanging bendex, you know, if one misses the start miss priming or whatever.


After the first start I mention above, where I spun and spun and spun the engine, I noticed the ammeter showing a solid plus 30 amps! After taking off I like to make a climbing turn around the pond in the winter just to make sure everything is warming up and working properly. It took about four minutes for the ammeter to drop to 20 amps where it stayed for about ten minutes more which was when I started having to aviat, talk to tower, and stopped looking at gage. I noticed after a handful of takeoffs that she was showing 20 amps and then the one time I could stare at the gage it just stayed charging at 20 amps for about 10-15 minutes then quickly dropped to < 1 amp. I have an older InterAv alternator which has worked flawlessly for years but wonder how asking it to kick out 20-30 amps or more is going to affect its longevity? I was thinking a generator or one of those light weight alternators might get cooked trying to actually crank out thirty amps for more then a moment.


I really only have about fifteen battery starts on the battery right now. My bird lives outside all winter up here in western Alaska were I will fly if the temperature is down to -20 degF. the battery will be exposed to -40 degF. I am thinking I should keep a new Gill-35 on the shelf just in case but will keep using the earthX battery because I think in the long run it has the potential to be a big improvement. Time will tell.

Ok, not so short.

Rocket

Why no turbine love? Seems like a missed opportunity for the market and vendor alike.

Christina Young wrote:Does anyone know how the EarthX battery will store over the winter in -40 to -60F temps? Will it kill the battery like with lithium-ion? I'm interested in this for my Stinson, but there is a possibility of it wintering over in my place in rural Alaska.

The storage temperature is -40 deg F. The details are found in the manual: https://earthxbatteries.com/wp-content/uploads/2025/12/180426-ETX900-TSO-Battery-ICA-Manual-RevI.pdf

The turbine market is coming! We currently have over 350 STC's for 12V aircraft, and we have a large submittal for 24V aircraft in the piston market pending now, and the Turbine market is in the works!

twofingers wrote:I've never been so excited for my battery to bite the dust, looking forward to upgrading when that happens.

I have a battery minder set up on my Concorde battery. Can that be used on the EarthX also? Or is there an equivalent?

You cannot use the brand Battery Minder as this is a desulphating lead acid battery charger, and a lithium battery will never sulphate so this mode can damage it. Here is a page on battery charging and options for you: https://earthxbatteries.com/our-batteries/battery-charging/

Is there any interest on making these available for LA4 (Lake Buccaneer) aircraft?

Thanks! This helps. However, where does it say -60 deg F? On page 17 at your link it says this:

If storing the battery, it can be stored at temperatures between -40°C to +70°C. The recommended storage
temperature is -10°C to 40°C. Our batteries have no liquid inside and will not freeze. Keep batteries in
their original packaging or use appropriate containers to prevent short circuit of the terminals and physical
damage.
If the aircraft is to be put in storage for an extended period (> 6 months), disconnect the battery cable to
eliminate drain from the Aircraft’s electrical system. A fully charged battery can be put in storage for up to a
year without charging but should be charged and inspected annually.

I'm really interested in this battery, just a bit nervous about it surviving a really cold winter like this one.

EarthX Batteries wrote:

Christina Young wrote:Does anyone know how the EarthX battery will store over the winter in -40 to -60F temps? Will it kill the battery like with lithium-ion? I'm interested in this for my Stinson, but there is a possibility of it wintering over in my place in rural Alaska.

The storage temperature is -60 deg F. The details are found in the manual: https://earthxbatteries.com/wp-content/uploads/2025/12/180426-ETX900-TSO-Battery-ICA-Manual-RevI.pdf

How about heat? Any real world experience out there with in-flight or post flight overheating conditions inside the cowl on firewall mounted earthx batteries?

Customer with an RV7, landed in 110F weather in AZ. Did not open his oil filler door or park into the wind like I recommended. Battery heat soaked during his hour on the ramp. After startup, as soon as alternator put a charge to it, the battery activated its heat trip safeguard, which resulted in it not accepting a charge. Alternator was still outputting that that time and pilot had no idea the battery had failed. He departed on the flight back to Socal and at some point in climbout the alternator tripped about 20 min out of his departure airport, probably from it not having a good load to absorb charging anomalies. He decided to return to his point of departure. His EFIS died when he was turning final. He had exhausted his entire EarthX charge and the Dynon backup batteries. Luckly he landed the aircraft by feel without too much issue and everything was resolved safely.

I do not believe the EarthX's compromises are worth the weight savings in most aircraft.

WorkingWarbirds wrote:Customer with an RV7, landed in 110F weather in AZ. Did not open his oil filler door or park into the wind like I recommended. Battery heat soaked during his hour on the ramp. After startup, as soon as alternator put a charge to it, the battery activated its heat trip safeguard, which resulted in it not accepting a charge. Alternator was still outputting that that time and pilot had no idea the battery had failed. He departed on the flight back to Socal and at some point in climbout the alternator tripped about 20 min out of his departure airport, probably from it not having a good load to absorb charging anomalies. He decided to return to his point of departure. His EFIS died when he was turning final. He had exhausted his entire EarthX charge and the Dynon backup batteries. Luckly he landed the aircraft by feel without too much issue and everything was resolved safely.

I do not believe the EarthX's compromises are worth the weight savings in most aircraft.

I’ve had a handful of those little orange AGM batteries on my bench all swollen up from overheating on the firewall. In Alaska.
180/185. I never thought the firewall was a good place for any battery type.

I think under the seat where all the Cub guys put it has gotta be the dumbest thing anyone ever dreamed, I suppose in a sealed box with vents?

Had a buddy Couple years ago in a 12 have an orange one overcharge and cook off under his ass, said he’s pretty sure he has permanent lung damage from the event.

Think about this if you’re in a significant wreck and your lead acid battery shorts out on top, so the box gets crushed or whatever shits gonna get red hot back there smoke red, glowing metal it’s not gonna be pretty. Ever see some googan stack a bunch of wrenches on top of their car battery. I bet there’s a bunch of YouTube videos

In the same scenario the EarthX Battery is just gonna shut off all the current probably in a millisecond.

In the end I think it’s important to use Whatever you feel comfortable with. You don’t wanna use one don't, it’s that easy.


Rocket

Rocket,

Great points! When I bought my 185 12 years ago it already had the Atlee Dodge firewall battery. I have the Selkirk flat aft baggage compartment (which I really like) but I'm considering going back to the original factory setup. The big old Concorde or Gill battery seem to leave very little to chance. Thoughts anyone?

MW

I live in just about the farthest South West corner of Arizona you can tuck in to. It gets warm here. Warm enough that most of our winter visitors wear shorts and short sleeved shirts throughout the winter.

I ran the wonderful little orange batteries until a better product came along. It is blue. The better product had some growing pains, nothing new with product development there, the first hammers probably weren't as good as today's.

My experience with swelled batteries of the orange flavor has been that it has not been from being on the fire wall (where mine lived) but from rate or extent of charge. In other words it wasn't the ambient heat that killed them (as Rocket pointed out it could have happened in Nome) it was the internal heat that killed them.

On the original blue batteries the same thing could be done. The newer ones have more tech *more tech means more safety if you know how to use it, or more failure points if you elect not to use it correctly, not much different than an Ipjhone compared to a rotary Western Electric on the kitchen wall. Not many people spinning plastic to call a friend now days....

FWIW, I'm not a blue battery sales person, but I've ran them in my planes for years and years, in the desert, it's warm here. I began long before they owned STC's. The process, or understanding that process for legal installation is obviously another passionate subject and not the topic of this thread, so no point in digressing there, other than to say, in all those years the ones on the firewall haven't burned the planes out of the sky, and the ones under seats haven't ejected me.

Another worthy note is that the planes I've used them on have been strictly VFR machines. No super computers, or 'fly for me' boxes. I am fully aware that many of today's electrons like to rule the roost, and not all electron using gadgets house electrons that want to get along with other gadget's electrons. If you fly an AI controlled ship, your experiments may not end as benign as my tractor engine driven ones have been.

Take care,
Rob