The International Cessna^® 170 Association

A great many ELT's have a Remote Control Panel Indicator (RCPI). This is the small rectangular control panel that activates your ELT remotely. It usually has an activation switch, a ELT ON indicator (flashing/pulsing red light), and a RESET switch. It "talks" to the ELT via a telephone type modular cord.
Many owners do not realize it has it's own battery that requires regular replacement. If you do not replace the battery at the specified time you are out of compliance and your remote switch will not work without a serviceable battery. (And you will be unable to RESET your ELT remotely should it activate inadvertently.)
The most common type of RCPI uses a battery that resembles a half-length AA, but is actually a SIX VOLT battery. It is a PX28L (Lithium) or PX28A (Alkaline). They can be difficult to find because many mfr's of these type batteries use different designations. You might find it listed as a 2CR-1/3N, or a L544BP, or K28L.
It is most commonly used as a PHOTO battery. I found that the local Radio Shack handles them, but the personnel at the store was unknowlegeable about how to cross-reference the battery.
It is Radio Shack part number 23-266 if you want the Lithium version. I recommend Lithium even though they are twice as expensive (about $10) as the Alkaline because:
1- Lithium has an 8-10 year service life. (ACK specifies that it must be replaced at 8 years.) Alkaline is only 4-5 years.
2-The dang thing is not easy to replace. It requires the removal of 4 tiny screws that thread into 4 tiny (1/4") nylock nuts that are not backed up and will turn when you turn the screw. The nuts are so close to the case that they are very difficult to hold while removing the screws unless you use an "ignition" open-end wrench. This means you have to get to the dang thing. It took me almost an hour (and I had to remove part of my avionics panel) just to change this little battery.
I do not want to do it for at least another 8 years!

Do NOT confuse this battery with the ones that fit in many auto key-lock remotes. It looks similar but it is not. It is a SIX (6) VOLT BATTERY. The POSitive end points AWAY from the front of the unit. (And you're going to need a very small phillips screwdriver to open the case for the replacement.)

Don't forget to make a logbook entry.

gahorn wrote: Don't forget to make a logbook entry.

Quoting A/C 91-44A, in part:

"Fixed type ELT installations are often permanently mounted in a remote area of the aircraft near flight control cables, vital aircraft components and critical attachments to the aircraft structure. Installations of this nature require an external antenna and often a remote on/off transmitter control switch that is usually located near the pilot's flight position. This type installation is complex and battery replacement should be accomplished by a certificated mechanic or certificated repair station."

John

I'm being facetious in the previous post, I hope. The wording of the A/C could be clearer, because I find it hard to believe that the installation of a remote control panel by itself makes the installation complex enough to require battery replacement by an A&P or repair station.

But maybe it does, if it's common for owner/pilots not to know that there's a battery there that needs to be replaced.

Best Regards,

John

The ELT itself is what that rule addresses. The RCPI may be just as complex...or it may not. My msg was only that it's battery should be replaced, and it should be logged.
How to do it legally is a different issue, and one that I presume we all know about.

After changing a few of those little batterys, I have come to the conclusion that it may be easer to change Aircraft
brad