Epirb battery replacement

Audrey II

Audrey II

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The other day a former boater gave me an epirb he kept when he sold his boat. He told me the battery was only a little over a year old but when I hit the test button it was clear it needs a new battery. I did a bunch of reading and many people insist that based on the age of the unit it should be replace rather then spending the money to send it out for service. Other people say replacing the battery is a simple thing to do and no need to send it out. I figured I had nothing to loose so I went ahead and opened the unit which turned out to be a simple thing not much different then changing the batteries in your car remote. To my surprise what I found was the battery looked like someone made it themselves by soldering three d size 3.6 volt lithium batteries together. Knowing the former owner this doesn't really surprise me, he like I are in the electronics installation businesses. The factory battery is in fact the same design but shrink wrapped together.
What I'm wondering is does anyone here have any knowledge about these batteries and or epirb in general.
Should I do the same, build my own battery pack
Should I buy a factory battery big $s
Should I toss the unit being it was made in 2002
 
I don’t think you can order the battery and do it yourself. As with life saving equipment I let the pros handle it. If the home made battery failed after a year... here is your answer
 
I wouldn't trust anything from a "former boater"...
 
Made in 2002? EPIRBS have come a very long way since then. In those years that likely TX’s on either 406.025 or 121.5 and definitely does not provide positioning. Nowadays you still get the hex on 406.025, but also a provisioned latitude and longitude, transmitted FROM the actual device up to the COSPAS-SARSAT constellation. No more waiting for a second pass from LEOS satellite. No waiting for confirmation and resolution. Modern devices also transmit a 0.1 watt 121.5 signal - so when I get the call to go chase down an EPIRB, the SAR controller has already called the contact on the registration (believe it or not, there are still people dumb enough to not register them and/or provide contact info) - I’m given a latitude and longitude. On the way to that position I also have a radio direction finder looking for tone on 121.5, so I can get even more precise location. With the GPS enabled devices - sometimes called GPIRBS - the RDF is probably not even necessary, but most EPIRBS in use are not the most modern ones on the market, so I only get an approximate position, so I use the RDF to narrow that down by steering 5 degrees or so off the signal. This confirms it’s not a reciprocal, it lets me know when I’m close (simple geometry - bearing will start swinging as I get close), and it’s just not good common sense to steer directly at an object you can’t see. 20 tons of boat will hurt you.

TL;DR version: Buy a new modern one.
 
I found a company that makes replacement batteries if you send them the old one. Yesterday I used a 12 volt battery to test the unit and it works, replacing the battery is really not a big deal. I think as a backup I will go ahead and fix it I may just order the best batteries I can find and and rebuild it myself. No there is not a chance I would do this for someone else but as a backup for myself I figure having it on board can't hurt!
Yes it is a 406 unit I have already registered it and surprised how quickly I received the sticker.
Sending this unit out forca new battery cost about $250 it's not worth the price there are new units that sell for about the same price!
 
IMO you have nothing to lose except the cost of parts to try. Do a search on YouTube for videos too.
 
The parts are cheap no more then $40 and as I said the unit is already registered to me and the boat. They were unbelievably fast with the process. As soon as I got the unit on Tuesday I did a little research then filled out the form online. Apparently they immediately emailed the old owner who didn't reply that night so they called him the next day to confirm he sold it or gave it away he confirmed and by Friday I had a new registration in the mail. What government office is this efficient?
 
I've found BatteryMart.com's listed lithium battery pack for ACR SatFind 406 EPIRB is the exact match to the original battery in my older Alden Cat. 1 SatFind-406 EPIRB in its tower bracket .
It just takes a few minutes to open, change out and close back up, including new greased o-ring seal. .
If going for time, maybe under a minute & 1/2.

https://www.batterymart.com/p-lo26sx-4nat-radio-battery.html

( Yes, I do have onboard a newer-tech Cat. 1 ACR V-4 GPIRB with 10 yr owner-replaceable battery pack , but it is just positioned near the lower station as a Cat. 2. )
 
I agree with your assessment it is about 90 to swap battery. The battery in my unit looks differ5it is three 8 D cell in series I have ordered a pack of four and will solder then together using the existing wires and diodes.
 
Recommend getting a REAL strobe and keeping it with your EPIRB. The ones on the units themselves are generally the bare minimum to meet certification requirements. People in the water are VERY difficult to see. If it’s at night, a good strobe will make an enormous difference in probability of detection.
 
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