IF YOU USE DURACELLS

gasman · #1 08-30-2007, 09:50 PM

IN YOUR ELT. HOW OFTEN DO THEY NEED TO BE CHANGED?

walter · #2 08-30-2007, 09:52 PM

I replace them at every annual, both the ELT proper and the remote.
It's cheap insurance.

lostpilot28 · #3 08-30-2007, 10:07 PM

I just had an annual done a few months ago on the PulsarXP I recently owned. The A&P I/A did the typical ELT tests which all passed. He then opened the ELT and looked at the Duracell batteries inside. The expiration date was March of 2008 (my annual was being done in May). He said to change them before the next annual, but they were technically "good" up until then.

gasman · #4 08-30-2007, 10:18 PM

I just removed the Duracell batteries that were dated 2010 and installed new ones that were dated 2014! The removed batteries had a 1% loss over the new ones. 9.675 volts and 9.505 volts total.

Are we allowed to go to the date on a Duracell battery? WOW! thats seven years. I would be pleased with two years.

Bryan Wood · #5 08-30-2007, 10:28 PM

I just looked at the manual for the ACK ELT and all of the batteries must be date coded and all must have the same date. After the ELT has been run for a cumulative 1 hour all cells must be replaced. Otherwise you can leave them in until their expiration. Of course the log book must be updated with the batteries. With this in mind I still change them at the annual condition inspection. Like the first response above, cheap insurance.

gbrasch · #6 08-30-2007, 10:37 PM

Quote:

Originally Posted by Bryan Wood

After the ELT has been run for a cumulative 1 hour all cells must be replaced. Otherwise you can leave them in until their expiration.

I believe the FAR states, in addition to the 1 hour rule, that they must be replaced after 50% of their useful life. (91.207 (C)(2)).

Pirkka · #7 08-30-2007, 11:28 PM

As said, cheap insurance. I woundn't mind change them every year whatever dates there are stamped. You can use them in some non-critical (non-aviation) application after they have been one year in your ELT. So no need to throw them away...

Dave Cole · #8 08-31-2007, 06:29 AM

No need to replace them either... A stated in a previous post, the TSO'd ACK ELT is approved for use with batteries that have not reached their expiry date, provided they have not been used for an accumulated time of one hour.

If you have not used your ELT (beyond an occasional quick check), replacing the batteries every year doesn't increase reliability by a measureable amount.

Incurring a cost with no benifit is not "cheap insurance".

buz · #9 08-31-2007, 07:21 AM

Why change them? Just open up the ELT and make sure none have leaked or corroded and maybe check the voltage to be safe. I would not replace yearly.

c177tx · #10 08-31-2007, 07:38 AM

Here is a link to an interesting article that help explain the ELT battery replacement issue. The one thing is that the 50% life of the battery requires that that if the batteries are good for say 4 years then they will need to be replaced every 2 years. so if the experation date is say 2011 then they will need to be replaced in 2009.

http://www.avionicswest.com/articles/eltupdate.htm