EarthX and G3X

[jmorrical]

I've chosen the EarthX ETX680C battery for my CarbonCub EX. There is a lot of good discussion here about battery choices... pro and con...so I hope this 'battery' thread does not go off the rails in that direction. I've made my choice.

I would like to ask how EarthX users integrated the EarthX BMS warning into the G3X. The EarthX Battery Management System (BMS) has a fault indicator light on the case. A black wire spade connector out of the top of the battery case can be used to wire a single warning light on the panel. I have also heard that warnings can be integrated and displayed on G3X where parameters/warnings can be set appropriate for the Lithium LiFePO3 battery.

Can someone give details on how that is done? Do I wire it to the GEA 24 engine interface module? What connector, what pin, single wire + a ground somewhere? How do I configure it on screen on G3X configuration page?


Screen Shot 2021-03-04 at 12.48.38 PM.png

[Andy]

. I have also heard that warnings can be integrated and displayed on G3X where parameters/warnings can be set appropriate for the Lithium LiFePO3 battery.

Can someone give details on how that is done? Do I wire it to the GEA 24 engine interface module? What connector, what pin, single wire + a ground somewhere? How do I configure it on screen on G3X configuration page?

You would need no additional wiring to customize the voltmeter and ammeter red and amber bands for this battery. If you want to wire the battery fault output you could perhaps make use of a GEA 24 GP input. The CubCrafters Exec Glass configuration already uses all 4 of the available GEA 24 discrete inputs. About the only advantage I can see for wiring the fault output to the G3X system is that a fault would probably be recorded in the data log. A panel warning light doesn't depend on anything else to be working and would be much easier to configure.

I doubt you find any better information than the G3X Touch installation manual. It includes information on how to configure all the available inputs and the resulting displays. Perhaps start with 35.4.32.3 EIS Configuration Options.

I have to wonder if you would be able to configure the G3X system to be smarter than the monitoring and protection that should be built into the battery.

[aeroaddict]

While this does not answer your question specifically as I run Dynon I would suggest just to keep it simple.

For a 1 1/2 years I have run the EarthX since airworthiness. I just wired up the LED warning light on the panel. Simple, easy to install and effective.

As Andy has mentioned, I'm unsure what would be used as parameters that isn't already monitored by the charging system.

A little off topic but the LED did light up once and reading the decoding information, I had a cell that was slow to charge. EarthX had me send it in and they tested it finding a bad cell. Replaced the battery and I'm go to go now.

Other than the one issue, the battery has been excellent. I even use a second one as my back up battery.

[jmorrical]

The G3X / GEA 24 Volts 1 & 2 is configured to have Red, Yellow and Green bands for a standard lead acid battery. By the time a 12v lithium gets to ~11.5v it is 100% drained. I’m told the normal resting voltage is 13.3v so I'm considering this configuration for Volts 1 with the following settings. Does anyone have any experience with the range I am considering for my G3X? I'm looking for advice.

• Red: 0-11.5v
• Yellow + Alert: 11.5-12.5v (alternator not charging)
• Yellow: 12.5-13.5v (alternator not charging)
• Green: 13.5-14.9v
• Yellow: + Alert: 14.9-15.8v
• Red: 15.8-16.0v

Below are the Carbon Cub provided Volts 1 and 2 settings from the CC11-160 Base.gca files in Dropbox that have been installed to my G3X. Should I change Volts 2 also?

• Red + Alert: 10.0-10.8v
• Yellow + Alert: 10.8-11.5v
• Yellow: 11.5-12.6v
• Green: 12.6-15.0v
• Yellow + Alert: 15.0-15.8v
• Red + Alert: 15.8-16.0v

[dayoung107]

Suggestion for the voltage ranges:
The volts for 1 and 2 should be setup according to the type of battery associated to that indication.
Volt 2 is the ignition backup battery, the rectangular 2 AHr battery in the right "cheek". If your ignition backup battery is still the lead-acid from the factory, do not change Volt 2 alert values.
If your main battery is an EarthX, I would interpret the following ranges for Volt 1 from their installation manual:

• Red+Alert: 0-12.6v
• Yellow+Alert: 12.6-13.5v
• Green: 13.5-15v
• Red+Alert: 15-16v

If you cannot select 0-12.5v for that low volt warning, you may need to change the gauge display range minimum to 0 thus allowing that lowest marking to be set to 0. After setting the gauge marking ranges, I would set the minimum displayed to 11.5v. This way the colored bar shows between 11.5v and 16v which reduces the amount of red displayed, and allowing better display of the yellow and green portions. Alternative to 0-12.6v, the lower Red+Alert range could be 11.5-12.6V and Garmin will interpret anything below that as part of Red+Alert.


Comment on instrument panel indicator:
Talking to EarthX, the indication for a weak or failing cell is the main reason for the instrument panel indicator. The G3X system, when properly set, will cover monitoring the voltage.


Question on EFIS integration:
I haven't had a chance to investigate the integration between the EarthX and the EFIS yet. Many of the conditions that are indicated with the light are flashing indications. When the EarthX indicator output is connected to an EFIS and programmed as a warning, does the EFIS produce an audible "chime" every time the battery flashes the indicator on? I.E. for the first condition in the fault table, will there be a warning sound every 10 seconds during the 5s on / 5s off flashing until the battery voltage is above 12.8V? Then if a cell is imbalanced, will it continue every 10 seconds until a weak cell is charged and balanced? This seems like it would be distracting, and a good reason to only have a light in the panel? Anyone have experience with this?

AndrewY

[jmorrical]

I see that Engine Monitor GEA 24 connector J244s pins 41, 42, 43 and 44 are respectively assigned as Discrete In 1,2,3 and 4. As Andy said they are all used in our Garmin installation. Looks like they are related to ignition and backup battery. My primary goal is to get the EarthX Battery Management System fault indicator light repeating on the G3X display as a warning of some sort in place of mounting an alert light on the panel. I found a Van's builder explain his installation in the statement below. That's what I want to accomplish. He however had pin 43 available. I wonder if I could use pin 44 or 45 and program "EarthX Alert" in a similar way.

I'm not sure if or why I would change Volt 1 parameters with this battery. I understand the lithium battery operational voltages are different from the lead acid battery. My goal is simply to have a warning that the Battery Management System is actively trying to protect the battery.

The BMS protects from over discharge, over charge >16 volts, excessive temperature, short circuit or bad cells. I don't have a clear understanding of the crowbar at the over voltage relay, but I guess it protects the electrical system from over-voltage.

Here is what a Vans builder said about his installation:
"Then I inserted it into J244 connector's position 43 and buttoned everything up. I fired up the G3X in configuration mode and accessed the GEA 24 menu for Discreet Input #4 and designated it as "Active Low", categorized it as "Red" alert and made the alert annunciation come up on the EFIS screen as "EARTHX ALERT". Everything seems to work well and when the lead is grounded to the batteries's negative post (per EarthX instructions) the alert is triggered. Really neat and no LED alert lamp required on the panel."


This is from the Garmin G3X Manual showing Connector J244 and the last few pin details.
Screen Shot 2021-03-04 at 10.56.45 PM.png

[Andy]

My goal is simply to have a warning that the Battery Management System is actively trying to protect the battery.

If you really want to have the warning on PFD/MFD you seem to have two options:

1. Combine two of the ignition warnings to one discrete input (CC does this on aircraft that don't have an AFCS control panel but use a separate LVL button).

2. Investigate the use of a GEA 24 GP input. Garmin says they can be configured as discrete inputs but I have no experience of doing it.

One day I may experiment with the GP inputs as I would like to have a pilot activated event marker in the recorded data.

[Andy]

2. Investigate the use of a GEA 24 GP input. Garmin says they can be configured as discrete inputs but I have no experience of doing it.

Seems easy enough to use a GP input for your battery alert. You will need an external "pull up" resistor if the battery alert is not high when inactive. See "26.5.12 GP (General Purpose) Inputs" and Figure 30-2.2 for wiring examples.

[Andy]

I had to wait for the fuel truck to fill the self service fuel tank so I experimented with GP input configuration. It seems easy enough to configure for any alert you would like e.g. -


lunch alert.png


The puzzle is that GP inputs support AFCS LVL so I don't understand why CC chose to compromise the ignition alerting for aircraft with a LVL button but no AFCS control panel.

[jmorrical]

The EarthX Battery Management System Fault Indicator is to be wired as Active Low. I am not clear what that means except that I know the manual says that I must include a 'pull up" resistor. I'm trying to understand it.

The Figure 30-2.2 shown below is from the Garmin G3X Manual, Rev. AM showing GP (General Purpose) Inputs. I have a couple questions.

1. Andy suggests I use GEA24 connector P243? The GP 7 Lo (pin 28) and GP 7 (pin 29) are available along with pin 18 in my installation. As already mentioned I understand a 5K pull up resistor and a wire to aircraft ground are required. There would be three pins added to the P243 connector. All are available.
2. Is it also correct that I could use GEA24 connector P244 for the same purpose? This connector has GP 3, GP 4 or GP 5 available using available pins 12, 15, 31 respectively along with pin 50. All are available in my installation. Only two pins with the 5K pull-up resister would be required and there is no LO pin to connected to aircraft ground.
3. Or is P243 my only option for some reason I don't understand?

Screen Shot 2021-03-11 at 3.41.12 PM.png

This photo shows my GEA 24 configuration page. Note the Discrete and GP positions...GP 6 and 7 are further down on the page not shown. I was just playing with GP 3 adding 'Battery' to become familiar with assigning configuration.

IMG_3332.jpg