EarthX Battery..I didn't know that!

[Lee]

To start, I love the earthX ETX680c battery placed in my FX3 6 months ago. I placed the quick connect cables (ETX-QCC4) for charging or jumpstarting if needed. I also thought these cables were a good idea should I have an alternator failure and could use them to connect a back up battery. Not so fast, there is a "gotcha".

Costco was selling a lithium jumpstart battery with a small compressor in a nice small/lightweight kit ($99). This particular kit is manufactured by Lion Energy (Lion Cub JC). I thought I was prepared in the event of a dead battery in the remote Back Country. My mistake.

For reasons I'm sure are unique to me, I left the ignition switch (key) "on" with master "off". The electronic ignition remained "on" continuously using current. Unfortunately, my ETX battery was "dead" in a matter of 4 days. I hooked up the jumpstart battery hoping to start the engine...nothing! The jumpstart battery didn't work. Fortunately, this happened in the hanger where I could hook the ETX battery to a charger (Optimate TM 275). After 15 minutes, the jumpstart battery works just fine. What is going on.
Live and learn....
The ETX battery has circuitry that does not allow over-charging (>15.5 V) or over-discharge (<11.5V) to protect the Lithium cells. Once the battery hits 11.5V, circuitry shuts the battery OFF. Meaning 0V across the terminals. Very different than lead-acid battery's that just slowly discharge with declining (but present) voltage at the terminals. These Lithium jump batteries require a background voltage to "turn on" before there're usable. I didn't know that. A jump battery that will not start a dead battery, makes no sense to me.

Solution to date… I've called several manufactures of <$100 jump batteries. They all have the same problem. They will not jump an "all dead" battery only a "mostly dead" battery, to steal a line from the Princess Bride movie. In my case, only a battery with >11.5V.
EarthX does have a Jump Pack battery they say will work on a zero voltage battery for $289. Disappointingly, this battery has a capacity of 7.8Ah versus the 14.0Ah of most other jump batteries at 1/3 the cost.

Hope my lesson helps some one.

[Narwhal747]

To start, I love the earthX ETX680c battery placed in my FX3 6 months ago. I placed the quick connect cables (ETX-QCC4) for charging or jumpstarting if needed. I also thought these cables were a good idea should I have an alternator failure and could use them to connect a back up battery. Not so fast, there is a "gotcha".

Costco was selling a lithium jumpstart battery with a small compressor in a nice small/lightweight kit ($99). This particular kit is manufactured by Lion Energy (Lion Cub JC). I thought I was prepared in the event of a dead battery in the remote Back Country. My mistake.

For reasons I'm sure are unique to me, I left the ignition switch (key) "on" with master "off". The electronic ignition remained "on" continuously using current. Unfortunately, my ETX battery was "dead" in a matter of 4 days. I hooked up the jumpstart battery hoping to start the engine...nothing! The jumpstart battery didn't work. Fortunately, this happened in the hanger where I could hook the ETX battery to a charger (Optimate TM 275). After 15 minutes, the jumpstart battery works just fine. What is going on.
Live and learn....
The ETX battery has circuitry that does not allow over-charging (>15.5 V) or over-discharge (<11.5V) to protect the Lithium cells. Once the battery hits 11.5V, circuitry shuts the battery OFF. Meaning 0V across the terminals. Very different than lead-acid battery's that just slowly discharge with declining (but present) voltage at the terminals. These Lithium jump batteries require a background voltage to "turn on" before there're usable. I didn't know that. A jump battery that will not start a dead battery, makes no sense to me.

Solution to date… I've called several manufactures of <$100 jump batteries. They all have the same problem. They will not jump an "all dead" battery only a "mostly dead" battery, to steal a line from the Princess Bride movie. In my case, only a battery with >11.5V.
EarthX does have a Jump Pack battery they say will work on a zero voltage battery for $289. Disappointingly, this battery has a capacity of 7.8Ah versus the 14.0Ah of most other jump batteries at 1/3 the cost.

Hope my lesson helps some one.

Good information, thank you for sharing. I will say that in my factory earthx 680c installation, I don't even know how I would attach the alligator clips to the battery terminals, the battery terminals are very difficult to access because they are almost flush against the sides of the battery compartment. I too made a mistake and left the battery on too long while I was updating some avionics databases, but luckily a couple of hours wasn't enough to take the earthx too far below 13 volts.

Tac-Aero trains to always completely remove the ignition key and hang it on the fuel selector after shutdown (and they also train to keep the fuel selector on "left" or "right", never both, when parked to prevent fuel transfer between the tanks). Part of my shutdown flow is to put the fuel selector on right and hang the key there with its keyring, unless I'm taking the key with me.

There was an incident where the main battery was run down in the manner you experienced due to they key remaining in L/R. The airplane was jumpstarted, and shortly after takeoff the engine failed because the alternator breaker tripped (excessive load demand from trying to charge the main battery and provide ignition + avionics/lighting power). Luckily the forced landing was successful and the airplane unharmed, but hearing about this really drove home to me the importance of managing the ignition switch properly after shutdown.

[Andy]

Tac-Aero trains to always completely remove the ignition key and hang it on the fuel selector after shutdown (and they also train to keep the fuel selector on "left" or "right", never both, when parked to prevent fuel transfer between the tanks). Part of my shutdown flow is to put the fuel selector on right and hang the key there with its keyring, unless I'm taking the key with me.

There was an incident where the main battery was run down in the manner you experienced due to they key remaining in L/R. The airplane was jumpstarted, and shortly after takeoff the engine failed because the alternator breaker tripped (excessive load demand from trying to charge the main battery and provide ignition + avionics/lighting power). Luckily the forced landing was successful and the airplane unharmed, but hearing about this really drove home to me the importance of managing the ignition switch properly after shutdown.

The only reason I want to prevent crossfeed is when parked on non level surfaces. When I park in the hangar I want any fuel imbalance to correct itself. Aircraft is hangared with fuel valve Off which allows crossfeed.

Interesting to hear of an alternator trip due to excessive load. However, there is no reason for this to stop the engine. Sounds like this event was rather poorly managed. Was there any attempt to use the emergency ignition battery?

In my FX-3 alternator current is monitored and there is a CAS alert for either abnormally low or abnormally high current. I would not takeoff with that alert displayed.

[Narwhal747]

The only reason I want to prevent crossfeed is when parked on non level surfaces. When I park in the hangar I want any fuel imbalance to correct itself. Aircraft is hangared with fuel valve Off which allows crossfeed.

Interesting to hear of an alternator trip due to excessive load. However, there is no reason for this to stop the engine. Sounds like this event was rather poorly managed. Was there any attempt to use the emergency ignition battery?

In my FX-3 alternator current is monitored and there is a CAS alert for either abnormally low or abnormally high current. I would not takeoff with that alert displayed.

Does keeping the fuel off prevent the fuel dripping from the exhaust after shutdown? It's not a significant amount of fuel that drips out on my plane, but enough to be noticeable in the drip pan. As to why T-A always want the fuel selector in L or R, I'm not sure, but maybe they just want to train people to do things the same way every time; I didn't consider the benefit of having the fuel evenly distributed by leaving it on both or off, though.

I don't remember all the details of the incident where the alternator CB tripped, as I recall the engine failed just as the electric aux fuel pump was turned off so the pilot was focused on the fuel system in the limited time they had to troubleshoot at under 500 AGL, and didn't get to the backup ignition power. One benefit of the new-style FX3 panels is that the aux pump, backup ignition, and pitot heat switches are all clustered together on the left side of the panel, so if something goes wrong it's easy to just turn all 3 of those on in one motion (even though pitot heat would probably not be beneficial in the event of engine problems).

[Andy]

Does keeping the fuel off prevent the fuel dripping from the exhaust after shutdown?

I was told it does but I don't think I believe it. The fuel system is pressurized to over 25 psi when you shutdown and any slight leakage past the shutoff in the injection servo is going to bleed down that pressure through the injectors, down the induction tract, and out the sniffle valve. I have never seen fuel dripping from the exhaust.

I tried shutting off the fuel when I reached the end of my hangar row and waiting for pressure to drop below 10 psi before I pulled the fuel cutoff. It seemed to reduce the drip but I got the timing wrong once and bled it to zero which seemed to make it harder to start next time.

[Lee]

I did purchase the EarthX jump pack. Drained the ETX 680C to below 11.5 V. No voltage between the terminals. The Jump pack worked flawlessly and starting the plane.

[EarthX Batteries]

I did purchase the EarthX jump pack. Drained the ETX 680C to below 11.5 V. No voltage between the terminals. The Jump pack worked flawlessly and starting the plane.

First off, thank you Lee for your business on the battery and the jump pack! Glad you are happy.

A little side note, the jump pack is a 12V or 24V jump pack, using Lithium Iron Phosphate cells (not lithium cobalt which is commonly found due to how inexpensive they are) and can easily start a 550 Continental engine, a diesel truck, construction equipment etc. We do not use "marketing" spec's to sell the jump pack, and there is a reason why you can find other jump packs out there at "1/3rd" the cost, and spec's that state that are triple the Ah, it just isn't true. Most packs are less than 2Ah. Their size and weight will give them away. If you have a jump pack that is 1 pound, vs. say the EarthX jump pack that is 4 pounds, by chemistry and physics alone, it just cannot be more power.


Fly Lightly,
Kathy Nicoson
EarthX Sales Director