GTN750xi current draw

Joe_B1

Joe_B1

Line Up and Wait
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Joe_B
Does anyone know how much current a GTN750xi pulls from a 12 volt battery? I need to update databases and there is no ground power available. Really don't want to run the engine during the update if I don't have to and I don't want to kill my battery. From what I can gather, this might take 15 to 30 minutes. My plan is to pull all the breakers except the one for the 750.
 
Not worth worrying about, just make sure battery is good before starting, and don’t transmit on the radio, transmitting uses lots of power.
I would expect less than 5 amps.
 
If you have an xi, it's way less time than 15/30 min. More like 2 - 3. I update my 650xi all the time off of the ships battery only. 650 likely a bit less draw due to smaller screen, but it's fast.
 
Is your ammeter mostly accurate? Turn on the master, turn on the avionics, then see how much current is being drawn. There might be some additional loads, so even if the 750 draws 10 amps, you might be showing more.
 
Thanks,
I had some issues and couldn't get it updated. The 750 could not read the card I loaded. So its back to the drawing board.
I think I found the problem, You have to name the SD card GARMIN or the 750 wont recognize it.

Joe
 
Joe_B1 said:
Thanks,
I had some issues and couldn't get it updated. The 750 could not read the card I loaded. So its back to the drawing board.
I think I found the problem, You have to name the SD card GARMIN or the 750 wont recognize it.

Joe
Click to expand...
Not sure the "Garmin" naming thing is right. You do have to have it formatted FAT32 and the card needs to be less that 32gb. I usually format my SD cards every three or four cycles to avoid loading errors. As an aside, my GTN card is labeled GTN, Works fine in my GTN650xi (and the plain GTN650 before I upgraded.)
You do need to format the card, not just delete the files. There are hidden files that need to be gone.

EDIT - also don't use an SDHC card, just a plain SD.
 
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Hang 4 said:
Not sure the "Garmin" naming thing is right. You do have to have it formatted FAT32 and the card needs to be less that 32gb. I usually format my SD cards every three or four cycles to avoid loading errors. As an aside, my GTN card is labeled GTN, Works fine in my GTN650xi (and the plain GTN650 before I upgraded.)
You do need to format the card, not just delete the files. There are hidden files that need to be gone.

EDIT - also don't use an SDHC card, just a plain SD.
Click to expand...
When I got the card (32Gb) class 10, I did a hard format and named it ARCHER. Then when I used their AP to load the update on, the directory structure looked just like the one that came with it. The only difference was the volume name and the actual update filenames. I just assumed it was because of the volume name. When I put it into the 750xi, it said no updates available. Anyway, I came home and put the new updates on the Garmin card. I also reformatted the new card and renamed it GARMIN and used the AP to put the new updates on it. So next time I go to the airport I am going to try the new 32gb card first and if that fails, I will update it with the original card. I'll post back and tell if the volume name made a difference.

EDIT: SD cards are limited to 2 GB, HC can go up to 32. I will try the HC version and let you know what happens.
 
You're right on the SDHC thing, my bad. One other thing you might be running into is the data you put in might be the same cycle as what's already in the GTN. Check the dates on the start-up screen. I will say that the updates can be a PITA until you get everything figured out. It's been a year since I've had issues, but it was 18 months of something every cycle when I first got the plane.
 
Hang 4 said:
You're right on the SDHC thing, my bad. One other thing you might be running into is the data you put in might be the same cycle as what's already in the GTN. Check the dates on the start-up screen. I will say that the updates can be a PITA until you get everything figured out. It's been a year since I've had issues, but it was 18 months of something every cycle when I first got the plane.
Click to expand...
The updates are the latest but I will check. Most of them on 750 show in yellow (expired) and the ones I put on the card are current. My bet is the volume name and if that doesn't straighten it out, I have a tech support contact at Garmin I can ask.
 
Oh yeah, gotta love Garmin. So I tried my new card today and the xi didn't see the updates. So I took the original Garmin supplied card and put the updates on that. What do you know, the updates went in.

So apparently Garmin has some hidden data on their card that the xi recognizes. I have a query into the tech support guy but I can guess what he is going to tell me.

However, I have a possible solution. The Garmin SD card is nothing more than a memory. If the xi can read it, so can I. My next experiment is to do a byte for byte clone of the Garmin card.

I have a program on my PC that can read every byte on that card and transfer an exact copy to another card. I will try this tomorrow and the next time I go out to the plane, I will try my clone card.

Stay tuned...
 
Joe_B1 said:
Oh yeah, gotta love Garmin. So I tried my new card today and the xi didn't see the updates. So I took the original Garmin supplied card and put the updates on that. What do you know, the updates went in.

So apparently Garmin has some hidden data on their card that the xi recognizes. I have a query into the tech support guy but I can guess what he is going to tell me.

However, I have a possible solution. The Garmin SD card is nothing more than a memory. If the xi can read it, so can I. My next experiment is to do a byte for byte clone of the Garmin card.

I have a program on my PC that can read every byte on that card and transfer an exact copy to another card. I will try this tomorrow and the next time I go out to the plane, I will try my clone card.

Stay tuned...
Click to expand...

Make sure the volume label is the same as well.
 
MooneyDriver78 said:
Make sure the volume label is the same as well.
Click to expand...
I did. Everything is as identical as I could make it with simple format and copy commands. The only thing I can figure is they have either a hidden file or hidden partition that the xi uses to allow the update to proceed. If this is the case (and I am not sure yet that it is), it kind of stinks that they would burn you for $150 after you spent a fortune on their box.

By doing a byte for byte clone of the Garmin card, all that secret stuff will be duplicated.
 
Joe_B1 said:
I did. Everything is as identical as I could make it with simple format and copy commands. The only thing I can figure is they have either a hidden file or hidden partition that the xi uses to allow the update to proceed. If this is the case (and I am not sure yet that it is), it kind of stinks that they would burn you for $150 after you spent a fortune on their box.

By doing a byte for byte clone of the Garmin card, all that secret stuff will be duplicated.
Click to expand...

In the old days when they used diskettes, they used to write a small file that was unreadable (CRC errors), if software didn’t get an error reading the special file it knew it wasn’t original.
Don’t know if they can do that with SD cards.
 
Well. That is interesting. I have microcenter 32GB class 10 SDHC cards and I have been unable to get the 750xi to recognize it. I guess before I embark on my cloning project, I will try other cards. I also have some SanDisk cards. Just out of curiosity, what card do you use that works?
 
Could be the unit is not reading the 32gb card? IIRC, When I wanted another backup card a few years ago for a 650, a tech at Garmin told me the max size card that could be read in the 650 was 16G. I found a SanDisk in Best Buy, formatted it FAT32 and it works fine.
Following the link for the Garmin blank card (010-01431-01) listed in the service bulletin reflects a $95 tag for the 8G card. Ouch....Checking Amazon, the SanDisk 16gb sdhc is <$7. I’m tempted to order one as a backup. I paid much more in the store.
https://www.amazon.com/SanDisk-16GB-Memory-Card-SDSDB-016G/dp/B0045KDHTM
 
The manual says "up to 32GB" but I just ordered a SanDisk 8GB card, that will be here Friday so we're going to find out. The Garmin tech has not replied to my email as of yet. I know at this point that the 32GB cards I had did not work.

I have seen this before in cameras and other non aviation devices. Some cards have more critical timing requirements. Some folks here say they have had no problems with the smaller SanDisk cards so I will give this a shot.

Something about $95 proprietary cards just rubs me the wrong way. I will find a solution to this if I need to!
 
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OK, I got it. First of all, you need an 8GB card. Sandisk is a good one and only cost about $7. Garmin has 4 hidden files on the real card. I dont know what they do but you need them on the card to make the 750 able to see databases. So if you have a windows computer turn on your view to show hidden files. Then you need to format your new card to FAT32 with an allocation cluster size of 65535 and name it GARMIN. After that, take your existing Garmin data card and copy it to a folder on your hard drive. Finally, copy the entire contents of that folder to the newly formatted card. You can then use fly.garmin.com to copy databases to that new card and the 750 will read it! It worked for me today.
 
Sounds like you got it. It is a pain in some ways. Once you have it set up it's quick and easy to update.

I flew a Baron with a 750 for a while. I updated the database on it. Never worried about the battery as it was so quick.

I do the updates on our SR22 now; the group was paying a mechanic $100 each cycle to do it. That's two USB drives for the Avidyne, even though the data would all fit on one, but noooo that's not "the process". I also update the cards for the two 430's at the same time. We need to get extra 430 cards so I can do them at home and just swap them.



Wayne
 
wayne said:
Sounds like you got it. It is a pain in some ways. Once you have it set up it's quick and easy to update.

I flew a Baron with a 750 for a while. I updated the database on it. Never worried about the battery as it was so quick.

I do the updates on our SR22 now; the group was paying a mechanic $100 each cycle to do it. That's two USB drives for the Avidyne, even though the data would all fit on one, but noooo that's not "the process". I also update the cards for the two 430's at the same time. We need to get extra 430 cards so I can do them at home and just swap them.



Wayne
Click to expand...
I think you are going to be shocked when you find out what those spare cards are going to cost you!
 
Joe_B1 said:
I think you are going to be shocked when you find out what those spare cards are going to cost you!
Click to expand...

I used to have a couple of them and a writer. Sadly I got rid of them. I've had to get a newer style writer. Yeah, they are not cheap, and look like they cost even more now than when I got two cards and a writer via eBay, but that was ~14 years ago.
 
wayne said:
I used to have a couple of them and a writer. Sadly I got rid of them. I've had to get a newer style writer. Yeah, they are not cheap, and look like they cost even more now than when I got two cards and a writer via eBay, but that was ~14 years ago.
Click to expand...
That writer cost $70 and the cards go for like $250 each.
 
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