Avionics Work on my NXCub

[lrobichaux]

Update to a previous post that I was considering some avionics upgrades after my avionics CB switch failed. Here is what I had done, and the results:

1) upgraded the avionics bus CB switch from 10A to 15A (shop determined that the existing wiring was sufficient to handle the amperage increase)
2) added a second dedicated back-up avionics power circuit with its own 15A CB switch (in case there's an in-flight CB switch failure like I experienced a couple of months ago)
3) installed a COM1 interlock tie-in as prescribed by CubCrafters to address static in my headset when transmitting and also monitoring both COM1 and COM2
4) upgraded the right ignition IBBS from a 3 amp-hour battery to a 6 amp-hour battery

Tech Aero based at KDTO did a fantastic job. Everything works as desired.

If anyone wants information on #3 above, reach out to Pete or I'm happy to provide information. More importantly, if anyone can make good use of a nearly-brand-new 3 amp-hour IBBS battery, first one to respond in the affirmative below I'll gladly package it up and send to you - no cost. I just want someone to get some use from it, as it's just gonna otherwise sit in my hangar and eventually become unserviceable. It's a TCW IBBS-12V-3AH for experimental installs. Does not have the install harness as that was needed for my upgraded battery.

 

[Cactus Charlie]

Thanks for the update.

I'm curious how you changed the IBBS battery. I thought the 6 AH battery was 2 3 AH stacked one above the other and required a bigger IBBS housing/case.

It's a while since my IBBS was open. My recollection is there is one battery connector but provision for adding a second one to the circuit board. Did your conversion add a second connector or does the "install harness" act as a "Y" to connect the two battery packs to a single connector?

I'll be happy to accept the unneeded battery.

 

[lrobichaux]

The IFR panel in my 2024 CCX-2300 NXCub with IO-393 came with two 3AH IBBS batteries. One IBBS provides back-up power for the G3X and various LRUs that are needed to provide basic PFD functionality (but does not power COM2, remote audio panel or GPS). The other IBBS provides back-up power ONLY to the right electronic ignition module - this is the one that I upgraded to a 6AH battery (which is one single battery, not two 3AH batteries wired together). Both original batteries came wired from CubCrafters as per described above, so the avionics shop simply unplugged the 3AH battery and plugged in the 6AH battery. The 6AH battery was same length / width (only a very slight bit taller) so it was an easy bolt in replacement using the same harness.

What's your mailing address for the battery?

 

[Cactus Charlie]

When you say IBBS battery are you talking about the complete IBBS LRU or the battery pack that is fitted inside it?

The IBBS batteries can be seen here - cwtech.com/product/ibbs-replacement-batteries/

I sent you a direct message with contact info.

 

[Neal]

3) installed a COM1 interlock tie-in as prescribed by CubCrafters to address static in my headset when transmitting and also monitoring both COM1 and COM2

Interesting. I have to check to see if I still have this issue as I have COM2 off right now. I have noticed this in the past.

 

[Cactus Charlie]

Garmin radios have a TX interlock IN and a TX interlock OUT. When two radios are fitted the OUT of each should connect to the IN of the other.

Is CubCrafers delivering dual radio installations without this interlock being wired?

 

[lrobichaux]

I think up until recently, CubCrafters were delivering without the interlock installed. After reporting the problem, Pete emailed me instructions for installing the interlock. I can forward y’all his email if helpful.

 

[Neal]

If you can provide the info here that would be great. How hard is it to do?

 

[lrobichaux]

Here is the battery I’m talking about.

 

[lrobichaux]

If you can provide the info here that would be great. How hard is it to do?

Stand by will go find it.

 

[lrobichaux]

@Neal here is Pete's email regarding the comm interlock. See below and attached file. Hope this is helpful

We believe we have a solution, we do need someone to test the fix ahead of releasing a service document. If you would like to be a beta tester, here is the information that will be coming out, assuming it works. We have done this to one aircraft and it seems to have worked.

Let me know if you have a mechanic who can do this and test it, that would be helpful in getting a second aircraft confirming this works.

The current solution we are looking for feedback on is connecting the wire between the GTR 200, plug P2001, pin 5 to the Audio Panel, GMA 245R, plug P241, pin 11. There is already a wire into pin 11 of the GMA 245R, the white VHF316A22-2. The interlock wire needs to tie into that white wire going to pin 11.

 

[Cactus Charlie]

Yes, as I suspected, you are describing an "IBBS" as an "IBBS battery" which was, at first, a bit misleading.

IBBS is "Integrated Battery Back-up System" and it contain a custom IBBS battery pack. What is unique about the IBBS is that each cell of the internal battery pack is charged individually. This means the IBBS internal battery can reach full charge even if the charging voltage is less than the fully charged IBBS voltage.

The 3AH IBBS circuit board has only one 7 pin battery connector but there is provision for adding a second connector. I suspect the same circuit board is used in the 6 AH IBBS units and the case is larger to accommodate the double stack battery pack.