EPIRBs battery expiry date

[renzo]

Hello everyone,

I am a radio inspector from many years, but I  still have doubts:
last one concerns the validity of the EPIRB' batteries.

The Resolution MSC/Circ. 1039 states that the batteries:

4. 2    Shore-based maintenance of all satellite EPIRBs, as defined in paragraph 1.2, should be carried out in accordance with these guidelines at intervals specified by the flag Administration and not exceeding 5 years. It is recommended that the maintenance be performed at the time when the battery is to be changed.


6.1     The main battery should be changed in accordance with the manufacturer’s recommendations, including the replacement of any other routine service parts (e.g. seals, memory battery, desiccant).
 
Well, when  the period of five years does begin? From the date of execution of the test operations conducted by the manufacturer? Or from the date of the EPIRB programming conducted by the SBM? and if the EPIRB has been kept in storage for 2 years and then programmed?

In particular during last survey I found two EPIRB built and tested on 2008.05.15 with batteries' expiry date May 2014.
The SBM has kept them in storage until January 2010 and then programmed with the MMSI of the vessel.


In your opinion, what is the expiration date of the batteries?

I would be inclined to keep as a reference date that one  of the  test performed by the manufacturer (and thus the batteries considered valid until May 2013).
What do you think about?

Thanks in advance.

Ciao.

Renzo

[Peter Leonard]

Hi Renzo,

Although I do not perform surveys any more, having moved onwards to other interesting realms of activity, I always took the manufacturer's date as the point of reference for replacement of batteries. Even if a battery is not used and is fully charged when stored, over time it deteriorates and loses capacity so that if it is only taken into use 2 years after manufacture, it effectively only has 3 years useful life left (of course we all know that such batteries last for aeons and in fact I've got a couple in my memento box which are +/- 20 years old and still hold a charge!, but that is irrelevant in terms of the regs). I would support your inclination to adopt May 2013 as the expiry date.

Would be interested in comments from other inspectors/surveyors in the field.

Ciao de Peter

[renzo]

Hi Peter,

it's very interesting the message fm Jotron about this question:

"Statemen regarding TRON 40S MKII battery expiery.

serial nr.  0580

We are manufacturer that produce more than 25.000 EPIRB and SART battery packs (lithium) every year. So batteries is never old in Jotron Stock. The type of batteries we use onnTORN 40S MKII is the SAFT LSH-14 light (same technology as the SAFT LSH20 used in TRON 40s). These batteries have less than 3% self-discharge pr.year (see links to data sheets in text).

The TRON 40S MKII is designed so that the batteries or new Epirb can be stored at least one year in distributors stock in addition to the up to 5 years useful battery life.

Therefore, we can confirm that the TRON 40S MKII, sn. 0580, produced 15.05.2008 can be labeled with a battery expiry date of until 15.5.2014 depending  of vessel flag requirements.
(Same flag require 4 years operation, while others use standard 5 years).

Jotron As

26 january 2010."


Ciao.

renzo

[fredivar]

Hi

Well, it was me who wrote the "Jotron statement" above to "renzo". And as it is said in the posts above, flag administrations may either use standard 5 years between performing SBM, or shorter (As I've heard Sweden and Italy require 4-years interval). When we say that it can have "battery due date" of until 6 years after production date, we are conservative as we know it will last much longer. EPIRBs are approved to specifications: IEC 61097-2, which states: 

4.6.2 Battery life and expiry date

The life of the battery as defined by its expiry date shall be at least three years.

The expiry date of the battery shall be the battery manufacturing date plus no more than half the useful life of the battery.

The useful life of the battery is defined as the period of time after the date of battery manufacture that the battery will continue to meet the input power requirements of the satellite EPIRB.
To define the useful life of the battery, the following losses at the temperature of +20 °C ± 5 °C shall be included:
a) self-testing, as recommended by the manufacturer or as required by the Administration, whichever is more demanding;
b) self-discharge of the battery;
c) stand-by loads.

So, to be able to say that the battery will last 6 years from production date, manufacturer have to prove that it will last at least twice the time.

Thanks.

Fred Ivar

[renzo]

Hi Fred,

thanks for your clarifications. It would be appropriate, in any case, to write the Epirb  battery expiry date on the first  test performed at the factory and attached to the EPIRB.
The same rule also applies to the  primary portable VHF batteries and Sart batteries. Isn't it?

A question OT:
Why dont' you produce anymore portable VHF working on 121.5 / 123.1 MHz?

Thank you.

Ciao.

Renzo

[fredivar]

Hi Fred,

thanks for your clarifications. It would be appropriate, in any case, to write the Epirb  battery expiry date on the first  test performed at the factory and attached to the EPIRB.
We have noticed your comments and consider to to do so
The same rule also applies to the  primary portable VHF batteries and Sart batteries. Isn't it?
If you by rule, means The expiry date of the battery shall be the battery manufacturing date plus no more than half the useful life of the battery, then it is NOT the same. Until now, the rule for these have been much simpler and only require that the capacity in hours after X years is equal or more than specification (capacity reduction caused by periodic Self Test during X years must be a part of the equation).

But in the newest specifications for AIS-SART, the same rule as for EPIRB battery capacity is applied (Which we think is a good idea)

A question OT:
Why dont' you produce anymore portable VHF working on 121.5 / 123.1 MHz?
We were not allowed to sell this radio anymore as a Wheelmarked (Europeean MED approval) product anymore because it will not be compliant with the latest IEC 60945 standard. There are as we know a dispensation in Sweden, and we are working on to get the same in Norway

Thank you.

Ciao.

Renzo

[Jeff_Harvey]

An FYI about batteries (of the sort sometimes used within beacons):

I've recently been investigating an obsolete battery used within an aircraft ELT. The existing battery in this ELT uses Li-SO2 chemistry and apparently doesn't meet any of the more "modern" safety standards. We have another beacon in the aircraft life-raft that uses similar batteries, and even they haven't been directly qualified.

Li-SO2 cells have some inherent dangers relating to possibility of venting poisonous SO2 gas, possibility of explosions and fires, etc. Modern Li-SO2 cells are designed to meet various standards (for aircraft: TSO-C97 [1997], TSO-C142a [2006]) that reduce these risks.

Because of the unavailbility of new batteries, the ones used in this ELT have been "extended" beyond the inital expiry date. Their remaining amp-hour capacity was confirmed (by sampling the inventory) and it was felt that this indicated that the cells were still "good". But I opened up one battery and found corrosion on one cell around the vent. I believe that this finding raises safety as a life-limiting factor. It also explains why the expiry date is supposed to be set at half the estimated life.

The point I'm trying to make is that, for certain 'more dangerous' cell chemistries, it might be worth ensuring that your batteries meet the applicable safety standards, and be very cautious of extending their life beyond the original expiry date (no matter what amp-hour capacity might remain).

Li-SO2 cells should be relatively rare these days. And modern cells should meet modern standards in any case.

But even so, I though this issue might still be worth mentioning.


PS: The beacons themselves, those using Li-SO2 cell chemistry, are supposed to meet all sorts of requirements with respect to how they react to a venting battery pack. The beacon itself is supposed to vent, not explode.