EPIRB Battery Test Results

[wrwakefield]

I finally got around to documenting the results from last fall when I tested the battery run time of an expired 406 EPIRB.

It was an older unit without built-in GPS, and was 7 years past the original battery expiration date. I had it removed from the life raft when it was repacked, and replaced it with a fresh, more compact PLB.

The results of the battery run time test surprised me; it ran more than twice as long as the minimum run time in the original specs.

Here are the details- including manufacturer recommended EPIRB disposal methods- in case anyone is interested.

Cheers!

Bill

[Stumble]

Bill,

Thanks for doing this. My belief is that EPIRBs are probably the single most important thing in saving your life if you ever have to abandon your vessel. As a practical reality there are places in the world where rescue will very likely take three to four days at least. My plan has always been to have enough EPIRBs and PLB's to be able to set them off sequentially. As part of my float plan I also have a list of the order in which I plan to set them off.

Primary EPIRB first, then wait 12 hours, then set off a plb, then 12 hours... Until they are all gone. The delay is to extent the total time of transmission.


I knew that the batteries would far exceed the rated time, but I had no idea it would be by this much.

[a64pilot]

I think storage temperature has a lot to do with shelf life of batteries, don't let them get hot and they will last a whole lot longer than if you leave them in your hot car often


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[Jim Cate]

Bill, thanks for that report. It supports my gut feeling that the specs are VERY conservative. Something that I have questioned before: the battery life is purported to be X years, but the required replacement period is X/2... how come?

The only question that comes to mind about your test is wondering if removing the antenna meant that the transmitter did not actually come up to full working power. The SWR seen by the output stage of the xmtr would be very high, and in some circuits, this causes the output to be ramped down. True in my ham rig and in my AIS... no idea about the EPIRB.

Jim

[a64pilot]

I think battery life is determined as something that has to be guaranteed, as in a poor battery that is poorly treated, worst case, and with a healthy safety factor.
The "scatter factor" often used in determining aircraft parts life limits is 7 to 1 meaning of course part replacement is required at 1/7the average life of the part. I believe it's based on being ultra conservative, as let you be right 10,000 times, but wrong just once and your in court defending it.
I'm surprised that there isn't two packs in an EPIRB with either one being able to meet spec.


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[lucseawalker]

Old expired EPIRB batteries last a long time indeed! Since my Mc Murdo one is 12v, I have been using the expired battery to make a simple LED light ... that way, I get to use that stored power before tossing it away in recycling!

I posted a video showing that simple project:

https://www.youtube.com/watch?v=Aj3Xv44XX8c

[RaymondR]

Assuming they don't broadcast a continuous signal, what is the duty cycle and actual time transmitting of these things?

[Nicholson58]

So. When will they come out with an EPIRB that:
rides on the boat electrical system
stays fully charged at all times
runs an automatic diagnostic including battery health
permits user replacement of batteries rejected by the test


Aside from the absurd cost to send one in for service, the time to ship and wait for it to return is an extreme imposition and added expense. AND, so far, every EPIRB I have tried to have serviced was:
still on its first battery
declared to be obsolete
OR battery obsolete.


I regard this equipment as critical. I also think that contrived obstacles to its maintenance in order to maximize cash flow to the makers (same as life rafts) is close to criminal theft. I really don't like having a gun to my head while someone probes my wallet.

[a64pilot]

The model for EPIRBS is for you to buy new every 5 yrs or so, not to service the one you have.
I tried to have the batteries replaced in a PLB I used to carry when ferrying aircraft over water and battery replacement was about the same as a new one, new one was smaller and supposedly better, so you can imagine I didn't have the batteries replaced.
I've been considering another PLB, but think I'll buy another EPIRB instead in another year when my current one batteries are mid life


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[RaymondR]

Originally Posted by Nicholson58

So. When will they come out with an EPIRB that:
rides on the boat electrical system
stays fully charged at all times
runs an automatic diagnostic including battery health
permits user replacement of batteries rejected by the test


Aside from the absurd cost to send one in for service, the time to ship and wait for it to return is an extreme imposition and added expense. AND, so far, every EPIRB I have tried to have serviced was:
still on its first battery
declared to be obsolete
OR battery obsolete.


I regard this equipment as critical. I also think that contrived obstacles to its maintenance in order to maximize cash flow to the makers (same as life rafts) is close to criminal theft. I really don't like having a gun to my head while someone probes my wallet.

I do not know how, or whether, registration is handled in other countries but in Australia you must register the usage details with a government agency and reregister at intervals. So, one not only has to go to the expense of replacing the EPIRB you must also do the administration for registration and provide yourself with documentation that you have done so.

Between the manufacturers and the bureaucrats the whole thing is getting out of hand.

[Nicholson58]

Originally Posted by RaymondR

I do not know how, or whether, registration is handled in other countries but in Australia you must register the usage details with a government agency and reregister at intervals. So, one not only has to go to the expense of replacing the EPIRB you must also do the administration for registration and provide yourself with documentation that you have done so.

Between the manufacturers and the bureaucrats the whole thing is getting out of hand.

We register here too. Cost is zero. Just imagine that when the EPIRB runs an auto system & battery test it also updates the registration. What a concept. The only thing you would ever have to do is change marginal batteries or failed devices. No humans involved and no questionable, too-old, EPIRBS. I don't throw out the car when the tires are worn. We manage massively more complex systems - THE BOAT - than one of these things.

I will buy PLBs when I find one whose batteries I can change.

[a64pilot]

I really, really want registration, I think it's very important.
First thing done when a 406 aircraft ELT goes off is they call the person on the registration. ELT and EPIRB are essentially the same thing, just airplane ones are mounted in the airplane and won't float, are set off by shock or manually, other than that, they same.
I've been called twice, both times they were in the avionics shop and somehow they set them off, but didn't launch anything from the RCC and no taxpayer money wasted.


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[Tikka]

Australian Coast Guard is collection point for expired EPIRB, at least in QLD.
Before they are disposed, EPIRBs must be disabled, I was involved in disconnecting internal batteries. Sure they many different types and brands, some good some superior
Perhaps one interesting finding, same models are easy to replace the batteries, after expiring date, same epoxied in than whole unit is disposable item.

[RaymondR]

Originally Posted by Nicholson58

We register here too. Cost is zero. Just imagine that when the EPIRB runs an auto system & battery test it also updates the registration. What a concept. The only thing you would ever have to do is change marginal batteries or failed devices. No humans involved and no questionable, too-old, EPIRBS. I don't throw out the car when the tires are worn. We manage massively more complex systems - THE BOAT - than one of these things.

I will buy PLBs when I find one whose batteries I can change.

Or, the holder you mount in the boat was standardised so that all EPIRBS fit a single holder and it contained an RFID device so that when you mounted the EPIRB it set itself up to broadcast the boats ID until changed by storing another mount.

If the EPIRB went in for battery change and testing it would be mounted in the workshops holder so that if the EPIRB accidentally broadcast during testing the authorities would know immediately that it was in a workshop.

Register the holder to the boat one time in the boats lifetime and automatically reset each new or re-batteried EPIRB automatically. Works for me.

[wrwakefield]

Originally Posted by Stumble

Bill,

Thanks for doing this. My belief is that EPIRBs are probably the single most important thing in saving your life if you ever have to abandon your vessel. As a practical reality there are places in the world where rescue will very likely take three to four days at least. My plan has always been to have enough EPIRBs and PLB's to be able to set them off sequentially. As part of my float plan I also have a list of the order in which I plan to set them off.

Primary EPIRB first, then wait 12 hours, then set off a plb, then 12 hours... Until they are all gone. The delay is to extent the total time of transmission.


I knew that the batteries would far exceed the rated time, but I had no idea it would be by this much.

Hi Greg,

I concur re: the critical importance of emergency beacons.

Our Beacon activation strategy is similar.

Hopefully the test results of this one out-dated device is not an outlier...

I will be adding some additional info to my original blog post as prompted by discussions in this thread...

Stay tuned, and thanks.

Cheers!

Bill