VM1000 Battery Chip Replacement

I am wanting to change the battery chip in my VM1000. I found the part number for the battery chip and bought the chip from Newark. Ready to go right? It looks like I will have to remove all the sensor wires and the ribbon cable in order to get the cover off of the DPU. Can this be true? My wiring was done very neatly but it is not labeled so this will be a little bit of a chore. Has anyone tried this task before. Is there something I am missing? Any thoughts would be appreciated.

Thanks in Advance!

Bill York
[email protected]
RV6 N477DH
Stellar Airpark
Chandler AZ

Bill, I did mine last fall. I have the EPI 800 (2.25" dia individual gauges) but I think the DPU form factor and hook up is identical. I planned on it taking a whole day, but was done in two hours. I had made up a "physical diagram" showing the box and all the wires going into it and their color codes. In my installation, the wires stayed pretty much right next to the connector they came out of, so putting it all back together was easy. I sent the diagram I made up to the e-mail address in your post. Good luck.

Dave,

Would you mind sending me the diagram as well? Mine may be a bit different (6 cyl), but it would probably be good reference info to supplement my original builder's schematic. I know this job is comin' eventually, so all info is appreciated! Was the DPU dissasembly and batt replacement pretty self evident? Thanks!

Also, Bill, can you pass the info on your source for the batt? Thanks!

Cheers,
Bob

The battery info that I found on the web was;

The chip is an ST M48T02-150PC1 "Timekeeper RAM" chip. I bought one from Newark or Digi-Key, I can't remember which. I believe that VMS specified an eight year replacement interval, but my aircraft's manufacturer (Diamond) initially specified two years in the maintenance manual, so I replaced it then. Subsequently, Diamond changed the interval to agree with VMS's eight years. The product datasheet lists a minimum data retention time of ten years. It lists for about $15 in single quantities

I bought mine from Newark Electronics but all the usual suspect carry it, Digikey, Mouser, etc. Hopefully it is the right one!

I will let everone know how it goes.

Bob - check private messages.

On how long these chips last - I had my unit about 3 years before the first flight and guess what, the chip died 15 minutes into the second flight. Replaced it and the next one was still running strong after 13 years, so I gave in and replaced it because I figured I was pushing my luck.

battery

Is there any soldering involved in the replacement, or is it a slide in battery chip? I'm at sixteen years on my original battery still working fine, but I'm sure my time in this mode is short lived........
Jim Baker
RV-6

The chip looks like a memory chip and it is suppose to just push into a socket in the DCU. You have to pry the old one out and replace with the new. All of this is theory and internet rumor of course as I have not opened mine up yet!

Dave, got the PM and replied with my e-mail...thanks!

My VM was an original install 12 years ago, but I don't know if owner 1 or 2 ever changed the batt. I know owner 3 (buddy) and 4 (me) have not. So I'm betting its "OEM". I feel the clock ticking on mine, but glad to hear some have gone longer, so I can figure this out and do it right!

I've considered going with a Dynon EMS to DSAB into my other EFIS's, but the VM is a nice piece of gear, and a batt change would be less complex than adding a D120...I hope!

Thanks for the info, and for any "post-op" updates you have on the "batt-ectomy"!

Cheers,
Bob