EarthX

[Slyfox]

I'm seriously considering this battery in my kitfox. I currently have the pc680. My question is: there is the ETX680 and the ETX680c, they claim that there is only a size difference but I want to know from people that have bought this battery what they would buy. I want the best of course. I also want to know if the charger is really needed. I fly a lot, at least 3 times a week. I have the 912uls in my model 4. thanks

[efwd]

I have the 680c which is starting my 912is beautifully. As for the charger, I have not used it since the first top off 3 years ago. I also fly regularly. I have a power source to operate the electronics during maintenance. I believe they have a charger now that can be utilized as a power supply. I will admit, I haven't really needed the power source either. Updating my Garmin stuff only takes about 40 min for the two EFIS. My battery doesn't have any problem running that stuff for 40 min.

[Slyfox]

doesn't the battery come fully charged? I don't have an efis so I'm good, all steam. I know old school, works for me.

[PapuaPilot]

I upgraded to the EarthX 680C from the Odyssey 680 years ago and love it. You don't really need a charger if you fly a lot. This battery holds its charge for a long time.

I did my first ever no preheat start a couple days ago at about 35 degrees for a spur of the moment flight. I hadn't flown the plane for about a month and had not charged the battery. It took at least 10 times cranking before I found the right amount of priming to keep it running. Even after cranking 10 times the starter was cranking great.

[Slyfox]

I did my first ever no preheat start a couple days ago at about 35 degrees for a spur of the moment flight. I hadn't flown the plane for about a month and had not charged the battery. It took at least 10 times cranking before I found the right amount of priming to keep it running. Even after cranking 10 times the starter was cranking great.


This is the main reason I want to upgrade. Even with preheat I have a hard time getting the starting power needed to start my engine in colder weather.

[Eric Page]

doesn't the battery come fully charged?
Lithium chemistry cells are often shipped with a "storage charge" in them, which is around 40-50% of capacity. At that level, self-discharge is very minimal.

EDIT: In response to Eddie's post #8 below, I should emphasize that my comment above refers to cells, not complete batteries. Addition of the active circuitry inherent in a battery management system will create a drain that must be offset over long storage periods.

[PapuaPilot]

For my upgrade I removed the battery from the tail and put the EarthX up front with only 3' of cable from the battery to the starter. The difference was amazing due to shorter cables, higher battery voltage (13.5 vs. 12.5) and minimal self discharge. Totally recommend it.

[efwd]

I do believe Kitfox stopped shipping the EarthX batteries with their FWF kits on account of batteries failing by the time they get installed. That is what happened to me. My battery self discharged below what could be recovered. The EarthX customer service was terrific. I wish I could recall her name but she usually answers the phone and she is extremely knowledgeable about their products. They ended up shipping me a new battery no questions. I believe the document inside the battery box tells you not to allow it to sit for so long. Unfortunately I never opened the box to read that until it had already sat for 2 years. They new I had neglected it and still stood by it and replaced it.

[Eric Page]

For those considering EarthX, you might want to look at the electrical section of your engine's installation manual, particularly for electrically dependent models like the Rotax "iS" engines. In the current 912iS manual, the battery specification requires a capacity of "at least 16 Ah."

Looking at the EarthX spec sheet (https://earthxbatteries.com/wp-content/uploads/2021/01/2021.brochure.pdf), the ETX-680 and -680C are rated at 12.4 Ah, at a 1C discharge rate. That means you'll only get that capacity from a brand new battery if you discharge it at no more than 12.4 amps. An aged battery, or a battery discharged at a higher rate, will result in lower capacity.

This makes little difference in how it spins the engine starter, but it's very important if both of the alternator/regulator systems fail. That leaves the battery to carry the ECU, fuel pumps, ignition system and airframe buses until you reach a safe landing spot. This is why Rotax specifies a 16 Ah battery, and is one of the drawbacks of lithium chemistries compared to lead-acid in the same dimensional footprint.

If your ship is a day-VFR-only machine, and you don't fly in remote areas or over hostile terrain, then you might be OK with a shorter battery-only endurance. Just be sure that you've done the load analysis so you know your plane's electrical demands and can choose a battery -- and test/maintain it in a way -- that matches your risk tolerance.

As an aside... The Odyssey PC680 is a 16 Ah battery. The EarthX ETX-900 has the same case size as their ETX-680 but offers 15.6 Ah capacity; compared to the -680, it's +$70 and +13 oz. It's still not 16 Ah, but it's darn close. Makes you wonder why EarthX uses the "680" designation for a battery that isn't equivalent to the PC680.

[Slyfox]

For those considering EarthX, you might want to look at the electrical section of your engine's installation manual, particularly for electrically dependent models like the Rotax "iS" engines. In the current 912iS manual, the battery specification requires a capacity of "at least 16 Ah."

Looking at the EarthX spec sheet (https://earthxbatteries.com/wp-content/uploads/2021/01/2021.brochure.pdf), the ETX-680 and -680C are rated at 12.4 Ah, at a 1C discharge rate. That means you'll only get that capacity from a brand new battery if you discharge it at no more than 12.4 amps. An aged battery, or a battery discharged at a higher rate, will result in lower capacity.

This makes little difference in how it spins the engine starter, but it's very important if both of the alternator/regulator systems fail. That leaves the battery to carry the ECU, fuel pumps, ignition system and airframe buses until you reach a safe landing spot. This is why Rotax specifies a 16 Ah battery, and is one of the drawbacks of lithium chemistries compared to lead-acid in the same dimensional footprint.

If your ship is a day-VFR-only machine, and you don't fly in remote areas or over hostile terrain, then you might be OK with a shorter battery-only endurance. Just be sure that you've done the load analysis so you know your plane's electrical demands and can choose a battery -- and test/maintain it in a way -- that matches your risk tolerance.

As an aside... The Odyssey PC680 is a 16 Ah battery. The EarthX ETX-900 has the same case size as their ETX-680 but offers 15.6 Ah capacity; compared to the -680, it's +$70 and +13 oz. It's still not 16 Ah, but it's darn close. Makes you wonder why EarthX uses the "680" designation for a battery that isn't equivalent to the PC680.

I guess I can say it doesn't matter to me. My plane does not have: efis, efi, transponder of any kind, don't use lights day vfr. so I guess it doesn't matter. But I do go into the back country. When I throw my master switch everything is off to the battery. no memory devices. I have a radio on line and a com (dynon) run a fuel pump (if the mechanical poops) IVO electric prop. outside of that nothing.

[DesertFox4]

If you are contemplating an EarthX battery, spend 15 minutes acquainting yourself with the EarthX charging requirements. On their website is a chart of battery chargers that are acceptable for charging their batteries other than the fully automatic Optimate chargers they recommend and sell.
https://earthxbatteries.com/our-batteries/battery-charging
I purchased the Optimate from EarthX with the continuous power option and have used it several times for hours at a time while upgrading and programing avionics.
I also have their jump pack which came in handy the two times I’ve left my Garmin Aera 500 on all night and ran the battery down.
BTW Steve, I have the EXT-680 for my 912uls and it is mounted in Kitfox Aircraft’s firewall battery box. The “C” version has same cranking specs in a slightly smaller case and slightly less weight.
29801

[Eric Page]

I've always been a bit suspicious of the charging requirements imposed by battery manufacturers. On the one hand, their products are perfectly happy to be charged by an alternator/regulator that throws lots of current at them (limited only by the system's current capability and the battery's internal resistance), and which has bus voltage that varies across the fleet. On the other hand, they imply that while it's parked in your hangar the battery must be pampered with very specific charging profiles. I'd be interested to hear an explanation of the physics behind this discrepancy.

[PapuaPilot]

I've always been a bit suspicious of the charging requirements imposed by battery manufacturers. On the one hand, their products are perfectly happy to be charged by an alternator/regulator that throws lots of current at them (limited only by the system's current capability and the battery's internal resistance), and which has bus voltage that varies across the fleet. On the other hand, they imply that while it's parked in your hangar the battery must be pampered with very specific charging profiles. I'd be interested to hear an explanation of the physics behind this discrepancy.
Curious indeed. I have wondered the same thing, but went ahead and bought one of the chargers that they recommend . . . :rolleyes:

While running our aircraft charging systems should be outputting approximately 13.5 to 14.5 volts. Too much voltage is definitely a problem, but I think the EarthX battery BMS would protect the battery.

[jiott]

I agree with Eric, seems odd, like maybe a marketing thing to sell chargers.
I do believe you should have a charger on hand; you won't use it much, but when you need it you really need it. In the 8.5 years I have been flying, 912uls, with lithium-iron batteries, I have needed the charger about 3-4 times. Either mistakenly left something on or was doing maintenance that ran it down. I started 8.5 years ago with the AeroVolz lithium battery and bought their charger. When I switched to the EarthX 680C I did not buy the EarthX charger, but have continued to use the AeroVolz charger. It has worked just fine the few times I have used it.

[Slyfox]

I bought a battery tender from Costco the other day for my Spyder. It has a setting for standard battery and lithium lifpo4. it will charge at 4.5 amps and than go to maintain. I love it on my spyder, I'm thinking it will do this earthx without a problem.

[PapuaPilot]

I bought a battery tender from Costco the other day for my Spyder. It has a setting for standard battery and lithium lifpo4. it will charge at 4.5 amps and than go to maintain. I love it on my spyder, I'm thinking it will do this earthx without a problem.
Probably, but EarthX has a list of charges they do and don't recommend.

[Slyfox]

Question? how to install this earthx. I have my battery inside on the firewall in the cockpit. Do I remove the pc680 and throw this battery in place and go flying or is there other things I need to do for the earthx first.

[desertdave]

Question? how to install this earthx. I have my battery inside on the firewall in the cockpit. Do I remove the pc680 and throw this battery in place and go flying or is there other things I need to do for the earthx first.

Plug and play or swap and fly.:cool:

[jrevens]

Check what your system charging voltage is. EarthX says it must be between 13.8 & 14.7v. You’re probably good to go, but if not it might be worthwhile looking at one of the new regulator/rectifiers from B&C… they have adjustable voltage capability.

[Slyfox]

I noticed today that mine is running right at 13.8. now if I did need one of these B and c regulators, what is the number needed for the Rotax 912uls, they don't show on the webpage specifically. thanks

[jrevens]

https://bandc.com/product/avc1-advanced-voltage-controller-14v-homebuilt/#installation-kit

[airlina]

I noticed today that mine is running right at 13.8. now if I did need one of these B and c regulators, what is the number needed for the Rotax 912uls, they don't show on the webpage specifically. thanks

Steve, I just went thru this when I just replaced my odyssey 680(with another odyssey). They list the charging voltage at 14.2V and my bus voltage was 13.9V . Found out from a recent kitplanes article that some voltage regulators are adjustable and in fact mine was, so I was able to bump up the voltage to 14.2v. So I would check to see if the one you are currently using can be adjusted before spending the bucks on a new one. Bruce N199CL

[Slyfox]

https://bandc.com/product/avc1-advanced-voltage-controller-14v-homebuilt/#installation-kit
is there a special wiring diagram for the 912uls.

[Slyfox]

Steve, I just went thru this when I just replaced my odyssey 680(with another odyssey). They list the charging voltage at 14.2V and my bus voltage was 13.9V . Found out from a recent kitplanes article that some voltage regulators are adjustable and in fact mine was, so I was able to bump up the voltage to 14.2v. So I would check to see if the one you are currently using can be adjusted before spending the bucks on a new one. Bruce N199CL

I'm currently using the stock regulator (I think ducanti) It's the same one my original 912ul engine came with back in 1994. I have the new one that came with the 912uls engine back in 2008 looks the same. I put that one in my tool box in case this one blows, but it keeps on ticking. lol

[Slyfox]

after reading everything on the B and C regulator I'm going to order the new regulator for the Earthx. I ordered the ETX680C will be here Tuesday. I will order the B and C tomorrow and both will be put inside the cockpit on the firewall. thanks all.

[jrevens]

is there a special wiring diagram for the 912uls.

Sounds like you got it figured out, but just to clarify - the B&C unit is a direct replacement for the Ducati that you have now (which is not adjustable). It uses the exact same connector, has the same footprint, and is wired the same way.

[Slyfox]

Sounds like you got it figured out, but just to clarify - the B&C unit is a direct replacement for the Ducati that you have now (which is not adjustable). It uses the exact same connector, has the same footprint, and is wired the same way.

fantastic, that means plug and play. way cool.