What's on your TCW IBBS Backup Battery?

snoop9erdog · #1 01-31-2019, 02:03 PM

What makes sense and what is too much?

TCW 6AH= 8A Max Continuous all outputs and 12a Peak Transient

When considering the load analysis:

Both 10" screens, GEA24, GSU 25, GTN 625, GAD 29, & Autopilotw/507 = 8.55 amps and more than max continuous. Critical to stay below 8a?

Both 10" screens, GEA24, GSU 25, GTN 625, & GAD 29 = 7.63 amps

Only one 10" screen, GTR 200B, GEA24, GSU 25, GTN 625, GAD 29, & Autopilotw/507 = 7.15 amps

G3X Instl Manual provides interconnect for both screens, GEA 24, and GSU 25 with regarding to the TCW.

Thoughts?

MarkW · #2 01-31-2019, 02:32 PM

The less you draw off the IBBS the longer it lasts.
My belief was it was emergency back up only. Only items meeded to keep me alive.
GDU-PDF, GEA and GSU are the only items I have on mine. I want ot be able to keep it upright and get it on the ground. I have an e-buss with quite a bit more but that is if I lose the alt and am running off of the battery only. IBBS is last resort.

snoop9erdog · #3 01-31-2019, 04:11 PM

Thx Mark. Love your 9.

Have you been satisfied with the TCW battery? It senses main battery voltage and then kicks on, correct?

Do you do as the manual says....power up everything first and leave ON?

Carl Froehlich · #4 01-31-2019, 04:54 PM

Or - two PC-625s in a thoughtful power distribution design, and no backup batteries.

Carl

Jeff A · #5 01-31-2019, 06:24 PM

1) EarthX ETX900 Main Battery for the whole airplane.

2) TCW Battery for the PFD, GTN, GEA, and GSU in accordance with TCW's drawing:

https://www.tcwtech.com/IBBS-12v-6ah_GTN%20&%20G3x.pdf

3) G5 with it's own backup battery.

Timberwolf · #6 01-31-2019, 06:59 PM

Concur with Jeff, plus the GAD29. No need to power both screens , let alone the autopilot. If I?m in the soup, I?m getting on the ground. If I?m VFR, I?d kill the 625 and whatever else I could to make my destination if able.

snoop9erdog · #7 01-31-2019, 10:17 PM

I agree. Great comments Shane and Jeff. A G5 with it's own backup battery is in the plan as well.

I'll likely take the gtr200 off and have a handheld comm for backup. The autopilot would be nice since it's amo load is minimal compared to other LRU's. I may add it but can shed it easily to conserve power if need be.

1 screen on the TCW is probably the way to go. I'll power up the other side thru the GAD 27 "keep alive power".

Walt · #8 02-01-2019, 08:53 AM

Quote:

Originally Posted by Jeff A

1) EarthX ETX900 Main Battery for the whole airplane.

2) TCW Battery for the PFD, GTN, GEA, and GSU in accordance with TCW's drawing:

https://www.tcwtech.com/IBBS-12v-6ah_GTN%20&%20G3x.pdf

3) G5 with it's own backup battery.

Having the GTN on there is interesting and presents a pretty heavy load on the TCW, when transmitting the unit may draw more than the 4 amps listed (10 amp breaker on the com side and 7.5 on the nav side) and generally uses 18ga wire to support that current flow. The feed thru CB on the TCW is shown as 10amp to carry everything?

Personally... I use the back-up battery for PFD, ADAHRS, GEA24 only.
If you really want a GTN or com on a backup I would use a separate TCW for this or larger backup source.

Carl Froehlich · #9 02-01-2019, 10:49 AM

Quote:

Originally Posted by Walt

Having the GTN on there is interesting and presents a pretty heavy load SNIP...

The GTN-650 is a power hog. If you must rely on a backup battery then dump the GTN-650 from the backup battery load, leave COMM #2 on the backup battery. Now add the backup battery(s) for whatever EFIS system you have.

Sorry to beat a dead horse, but shifting from a plethora of backup batteries to just two PC625s or similiar provides options for better redundancy and electrical reserves.

Carl

snoop9erdog · #10 02-01-2019, 01:24 PM

I have a GTN 625.....so no comm. Specs say it uses 1.8 amps.....max 2.8 (but I believe that applies to the 650 as well)

I'll only have one GTR200B for my comm. If i'm in the soup shooting an approach, wouldn't the priority be to keep the GTN for navigation over having the comm? Would have a handheld as backup for comm.

Explain your duel battery system Carl. I'm assuming you run off a main batt, then have diodes/switch to trickle charge and activate the second/backup? In this setup...is it far superior to a TCW because of the additional endurance AH capacity? Expound.

If my main Alt goes TU...I have at min an hour on main batt until it goes to min voltage to trigger the TCW...at which point I'd have at least 45min - to 1hour with the IBBS to get on the ground. More if I pull a few breakers and a =m able to shed the GTN. Depending on how much I've already flown prior to the electrical issue.....I'm probably going to start having fuel issues before I run out of electrons. ?? No?