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TruTrak ADI backup battery

CD.

Active Member
I have a TruTrak ADI as a backup attitude indicator. I only fly VFR currently. There is a switch on the panel to go to the back-up battery on the ADI... but the unit powers off when I test it. I assume the back-up battery is dead.

I did not build this aircraft and have only owned it since early summer, so I am still learning about it. The documents I have found on the ADI mention the back-up battery for the ADI and how to test it, but never show any pics or diagrams, nor how to replace it or what to replace it with. I have searched the forum unsuccessfully. I have yet to try and access/remove it from the panel.

If anyone has any information, insight or pics, I would greatly appreciate it.

Thanks,
chad
 
Looking at the manual and attached harness diagram, it should be easy to wire trace.

Edited after seeing the connector pin out top right in the attachment.

Looks like the advice below get a TCW-suggested unit is best.

It is possible the backup battery is home brewed and not on a separate harness- trace from the switch on the panel. I use in line diodes to the power + pin so the higher voltage battery powers the ADI if the E-buss switch is on. Switch off, master on, only the normal electrical system and battery power the ADI and charges the backul battery through another diode so the small backup battery cannot power the main bus.

It also keeps the main EFIS from brownout during engine start with the same switch on.
 

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My suggestion is to contact TCW, as they offer a great replacement for that product. We discontinued it TruTrak many years ago and began offering the TCW as a replacement.
 
Thanks for the info. I do appreciate it!

My RV-7A has 2 battery system and the ADI is powered from the 'Essential' bus. And all the time I've spent upside down, my feet sticking out the canopy with my head on the rudder pedals, I've never noticed a back-up battery hidden anywhere. :rolleyes: I will have to pull my GRT HX screen to be able to access the ADI and then I can physically follow the wiring and see where it takes me! :)

Thanks again,
chad
 
That battery pack is no longer available. I took mine to batteries plus and they replaced the cells. Works awesome, they last about 4 years between replacement. They use the same cells that came out of it.
 
I opened mine and replaced the cells. You can buy replacements on Amazon. They are just rc car battery pack cells. It's pretty easy if you have basic soldering skills.
 
Well... look what I discovered today! I had to be a upside-down contortion artist to find where it was mounted and remove it :eek:
 

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The battery box had a rattle in it... didn't seem right. So when I got home, I took it apart and this is what I found. :eek:

I think it goes back like I am holding it... can someone confirm the orientation of the transistor? :confused: I think I can easily solder it back on. It appears to have been mounted on the back. There isn't enough clearance for it to have been mounted on the front of the board.

I'm going to try an find a compatible battery bank to replace the battery with... but I haven't searched for one yet.

Thanks so much,
chad
 

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Here is a picture of the inside of mine. I just opened it up this week to try and find replacement batteries as well. I went to Batteries, Bulbs and more and the only battery he could find was a TEC 10019 which is a NIMH of 900 MAH, which is slightly lower than the 1100 of the previous pack. I am still waiting for them to come in to be sure they will fit the box but assuming that they due he quoted $50 to make it into a pack like what was in there.
 

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Thanks for those pics. It is definitely interesting how your transistor is soldered. The legs on mine definitely weren't twisted like that. I think my board may be a little different. I know the tiny component holes on the back aren't the same as mine. My inspection date is 4/24/09... I can almost make out the date on yours, but not quite...

I'll be really interested how your battery pack turns out... I'm still searching...
 
I did get the batteries and installed them and they seem to work fine. They are a little smaller which goes with the slightly lower MAH rating but otherwise seem fine.
 

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Thanks for the update! I'm glad they worked out. Was it an already assembled battery pack, or did they have to assemble it?
 
They were individual batteries and they (Batteries and Bulbs) assembled them together and fixed them in the box with some type of adhesive. It looks like they applied a non-conductive plate top and bottom but didn’t wrap them in shrink wrap as originally made. The $50 charge included the batteries and assembly and they had it done on the same day they called to say the batteries were in.
 
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