Avidyne MFD CMOS battery replacemnet

Hi, Does anyone have had to replace the CMOS battery of the Entegra 5000 MFD ?

If yes, what costs were involved ?

Jaap van der Klooster


On the member side is a lot of information that you can search on this subject. The quick answer if the MFD is in the shop already for some other repair they charge about 1300 USD. What they would charge for that only I don’t know. It is not covered by the extended warranty.

The battery is completely optional. It helps the MFD retain time and location, which it will get from the Garmin 430 as soon as they come on line.

The additional problem I face with the battery failure is that the Entegra MFD does not accept any Jeppesen ( Navdata and Electronic Charts ) update…

Avidyne quoted me USD1600 for the battery change to be done in their facility… seems over the top…

Those are 2 unrelated problems. The battery has absolutely nothing to do with the not loading.

A company called Extant does all repairs for Avidyne and they are the ones with the over the top change.

You probably have to fix something for the loading, but the battery repair, while recommended by Extant, is not required by Avidyne. It is your option.

Thanks Roger for your quick reply !

The odd thing is that the 2 “problems” occurred at the same time, I will go to the plane tomorrow to try loading the udates again. For the time being I will not have the battery replaced.

Last week I flew from EDSB ( Baden Baden ) to LOWS ( Salzburg ) and the MFD screen suddenly turned “black”.

After resetting the breaker, the problem disappeared.

I looked on the Members Forum under “Avionics” and saw that more people have faced this problem.

It certainly sounds like you are having issues with your MFD and it may need to go to the repair center eventually. Hopefully you have the service plan. If you do those issues will be covered by the Service contract.

The cmos battery in the MFD is not covered by the Service contract. Extant tries their level best to scare you into replacing it and they charge ridiculous fees to do it. Avidyne has written into the documentation the battery is optional. It only contributes saving dates and times. If it fails, what you will notice on start up is a blue screen that warns the batttery has failed. Then you press proceed and the MFD continues to boot and will work perfectly once it gets that data from the Garmin 430.

I concur, with the other issues being faced here, I would recommend buying the extended warranty program from Avidyne and sending it in after the 60 days to get it repaired.

FWIW @DaveFeatherston at Nexair was able to replace my MFD battery at a fraction of the Extent charged price.