What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Earth-X Battery Life and Death

wawrzynskivp

Well Known Member
Hello All,

I installed an Earth-X battery in my engine compartment about five years ago. Earth-X claims 5-8 years of life. Has anyone carried one of these to its dotage that can share what the final days of this battery are like?

Lead acid types sulphate, and generally begin to consume amps without effective charging retaining less and less storage capacity at an increasing rate.

Same for Li Iron?
 
Lions grow dendrites that effectively short accross and diminish life. If you can charge and discharge in spec or what the BMS likes, there is essentially no wear/tear in the 40% to 80% capacity range.

LiFePO4 battieries go thousands of charge/dischages in many applications because it is a reduced dendrite-supporting chemistry. Traditional PED lions go hundreds. It's less energy dense than older lithium polymer types, but safer when shorted.

Not sure if EarthX BMS treats the capacity like Tesla, but 5-8 years is great for a high surface area pouch battery layout that can crank our engines.
 
Last edited:
Lions grow dendrites that effectively short accross and diminish life. If you can charge and discharge in spec or what the BMS likes, there is essentially no wear/tear in the 40% to 80% capacity range.

LiFePO4 battieries go thousands of charge/dischages in many applications because it is a reduced dendrite-supporting chemistry. Traditional PED lions go hundreds. It's less energy dense than older lithium polymer types, but safer when shorted.

Not sure if EarthX BMS treats the capacity like Tesla, but 5-8 years is great for a high surface area pouch battery layout that can crank our engines.

Thanks,

Just got some feedback from Earth-X and they say the same thing. General decline in storage just like lead acid, higher probability of fault detection. Need to ensure access to battery's own LED to determine if fault light is flashing or solid. Battery should still work when fault is detected. But if LED is solid battery should be removed from service as soon as practicable because certain safety protections may be unavailable.
 
Non-Event

My first EarthX lasted moments past it's fifth birthday. It lived in my tractor for another couple of years.

Cheers, Sean
 
My first EarthX lasted moments past it's fifth birthday. It lived in my tractor for another couple of years.

Cheers, Sean


Now watching its golden years in your tractor would you feel confident leaving the next one in your airplane until you observed it flagging?
 
Capacity test would quantify . . .

The LiFePO chemistry is formulated for deep cycle and lingering indefinitely at low SOC, state of charge. That is what hybrids do, typical SOC is mid range so it is ready for charge or discharge. [This is not something to do on a PbA battery.]

That means you would have no issues or damage to the battery to run a capacity test under repeatable conditions, particularly temperature and load. Just add a load for a certain time (probably 1C rate) then precisely measure the voltage drop during loading and after. The drop won't be much but would be a good indicator of capacity. Deciding when enough is enough is on the user.

All this will work and might be fun if you aren't experimenting with something else. As a maintenance strategy sounds like a self inflicted pain. Popular these days.

Finally - temperature is the killer so life in the tractor is likely much longer than in the plane.
 
Now watching its golden years in your tractor would you feel confident leaving the next one in your airplane until you observed it flagging?

Nope! Just reassurance it won't kill me immediately. I'll confess I continued to fly it until the new one arrived.

Cheers, Sean
 
4 years and a week for me, about 100 hours per year. It was overtemped quite often the first year.
I’ld say the last 15 hours/2-3 months of flying sometimes the first crank wouldn’t pass the first compression stroke, a subsequent start was pretty normal. My last start was out of town and cold soaked at 40*, it wouldn’t pass the first compression stroke. After several tries it wouldn’t activate the starter. After a preheat and charge (went through full charge cycle in 20 secs) it started the engine fine. Batt Fault was on for the flight home with no issues, I tested it back home and it started the airplane just fine after I landed. Fault light is still lit up sitting on my bench, Replaced it with a new EarthX.
I thought it was very similar to a dying AGM.
 
Last edited:
4 years and a week for me, about 100 hours per year. It was overtemped quite often the first year.
I’ld say the last 15 hours/2-3 months of flying sometimes the first crank wouldn’t pass the first the first compression stroke, a subsequent start was pretty normal. My last start was out of town and cold soaked at 40*, it wouldn’t pass the first compression stroke. After several tries it wouldn’t activate the starter. After a preheat and charge (went through full charge cycle in 20 secs) it started the engine fine. Batt Fault was on for the flight home with no issues, I tested it back home and it started the airplane just fine after I landed. Fault light is still lit up sitting on my bench, Replaced it with a new EarthX.
I thought it was dry similar to a dying AGM.

Thanks for sharing
 
Is there a battery tester like the one I use on my AGM battery that can test the health of the Earth-X battery?

The battery tester I have allows one to test different types of batteries but LiFePO4 batteries are not one of the types listed in the menu.
 
Last edited:
I left the master on by mistake with my 3 year old EarthX and it discharged it down to zero. Now when fully charged with the LiPo4 specified charger I keep it on as a tender it has the same trouble at start getting past first compression stroke. I guess I whacked it when I left the master on for a few days. I am installing an anti-brain fart reminder light in an effort to mitigate future embarrassment. So I think a fully discharge event on the EarthX might be a death knell.
 
Battery Monitoring System BMS

Jim,

Did your battery have a BMS? My understanding is that that system will prevent damaging discharges (if working properly).

I bring that up because our engine compartments can very easily overheat the Earth-X. Stick on temperature tell-tales will go on my next battery for sure.
 
I'm in the middle of my annual this year, and with a 4-year old ETX900 I wanted to know how long it would last without an alternator in the air. 3 times in the history of this battery it has been run down flat to the point where the BMS took it offline and I had to charge it back to health.

My airplane is electron dependent for both engine power and nav, so I have dual alternators - what I was curious about was what would I have left in the event I had a legit double alternator failure while airborne. In that case I can loadshed down to just the critical components to keep the engine running, which would draw 9 amps. I have a backup Dynon Skyview battery that's good for 45 minutes minimum for the EFIS. I set up the panel today to simulate that 9 amp draw with a combination of instruments (no running engine) and started a timer. Beginning voltage was 13.2, at 45 minutes the voltage was 12.9. I increased the current load to 12 amps, and 20 minutes later the voltage was 12.6 and I got the first alarm from the BMS system (5-sec on/off flash). I discontinued the test at that 1:05 point.

So that's one datapoint - a 4 year old ETX900 that has been drained flat on it's face 3 times, still has a solid 10 amp-hours reserve capacity, at a minimum.

For my purposes, it means I can lose the primary alternator and continue on the backup, then lose it, and have a reliable 45 minutes of full EFIS capability to find a good place to get down, plus at least another 20 minutes with an EFIS that could give up any moment. That's sufficient for my personal risk aversion model.

EDIT - my battery is installed aft of the baggage compartment, not exposed to heat.
 
Last edited:
Jim,

Did your battery have a BMS? My understanding is that that system will prevent damaging discharges (if working properly).

I bring that up because our engine compartments can very easily overheat the Earth-X. Stick on temperature tell-tales will go on my next battery for sure.

1.) All EarthX batteries have a BMS. It is built into the battery itself. So the answer is yes. In my case the BMS alert wire it is connected to a discrete G3X system GEA 24 input to flash a "EarthX Battery" warning message on the flight deck screen. It hasn't ever tripped since set up and testing, at which time it was working properly.

2.) My battery is behind the baggage bulkhead in the back of the fuselage. It is the vented EXT900-VNT model.
 
EarthX Battery charger

Is there a battery tester like the one I use on my AGM battery that can test the health of the Earth-X battery?

The battery tester I have allows one to test different types of batteries but LiFePO4 batteries are not one of the types listed in the menu.

Gary,

EarthX has a battery charger/maintainer/power supply specifically for the EarthX batteries. Looks like you could leave it plugged in continuously.

https://earthxbatteries.com/shop/optimate-tm-275-9-5a-13-2v-lithium-battery-charger
 
Last edited:
already on there

I left the master on by mistake with my 3 year old EarthX and it discharged it down to zero. Now when fully charged with the LiPo4 specified charger I keep it on as a tender it has the same trouble at start getting past first compression stroke. I guess I whacked it when I left the master https://www.theblaze.com/news/actor...m_term=ACTIVE LIST - TheBlaze Breaking Newson for a few days. I am installing an anti-brain fart reminder light in an effort to mitigate future embarrassment. So I think a fully discharge event on the EarthX might be a death knell.

Leave your nav lights on. They make a great “already installed” indicator light.
 
That's been my go-to. Also a great external reminder and prevents the walk across the apron to go check. Can look at the plane from across the apron and see the nav lights are on/off to answer the question. Quick double check before closing the hangar door. Easy to see from a distance.
 
I left the master on by mistake with my 3 year old EarthX and it discharged it down to zero. Now when fully charged with the LiPo4 specified charger I keep it on as a tender it has the same trouble at start getting past first compression stroke. I guess I whacked it when I left the master on for a few days. I am installing an anti-brain fart reminder light in an effort to mitigate future embarrassment. So I think a fully discharge event on the EarthX might be a death knell.

I did the same thing - now I just leave my strobes on all the time. When I walk away if the strobes are on then so is my master.
 
I did the same thing - now I just leave my strobes on all the time. When I walk away if the strobes are on then so is my master.

Thread drift but I’m guessing the lights are still on a switch like the master, I suppose you could wire the lights to the master switch.
I developed a habit of checking the 4 M’s (Music/Mixture/Master/Mags) before shutting the door/canopy when exiting.
 
Thread drift but I’m guessing the lights are still on a switch like the master, I suppose you could wire the lights to the master switch.
I developed a habit of checking the 4 M’s (Music/Mixture/Master/Mags) before shutting the door/canopy when exiting.

Mine are on a separate switch. It was way less effort to leave it wired that way and just leave the switch up!

I shut the avionics off, then mags once the prop stops, then master. Just my technique.
 
Battery Monitor

This is a picture of a battery monitoring device I used during my RC days. (Cost less than 15 bucks on Amazon) Every 3 or 4 months when the cowling is off (Oil change) I attach this to one of the batteries and use a 100-watt light bulb (Old style) to test the AHrs that the battery holds. (It totalizes the AHrs) To use a 100-watt bulb you will need a cheap 150-watt inverter. I use to directly attach a 12-volt heater rated at 120 watts but that broke, and I've got plenty of old light bulbs around. Starting at ~12.7 volts on my EFIS I turn on the master and watch when the EarthX light goes into its low voltage mode. 2 years and 200 hours plus another year during the build turning the EFIS on and off. This is the battery located in the lower section of the cowling FWF which runs the hottest. ETX900. Took this picture today. I alternate start batteries depending on if it's an odd or even day. I prefer not to get to "dam will not start" just use other battery as a fallback. When it gets to less than 40% ampacity time to get a new one. (Or plan B, dam it will not start order a new one) If anyone has data on when to swap out, I'd be interested. My guess is my essential bus battery (Hottest of the 2) will fail first.
 

Attachments

  • EarthXBatteryR V.jpg
    EarthXBatteryR V.jpg
    721.5 KB · Views: 126
i have a 2 port usb plug in my panel from steins. you can pick up a bright little usb led for $1. can't miss that bright light if the master is on. i never take the light out of the spare port.
 
. . .. I am installing an anti-brain fart reminder light in an effort to mitigate future embarrassment. . . .

I leave my strobes switched on. Very obvious if I forget the master. I had a master stick closed on me once. The strobes told the tale.
 
Back
Top