DIY ACR EPIRB Battery replacement

Mar 11, 2015
357
Hunter 33.5 Tacoma, WA
My ACR batteries were up for replacement, and rather than sending it off to get them replaced I elected to do it my self. An unbelievably simple task.

Aqualink: total cost, $25.00
RLB-35B: total cost, $45.00

Batteries for Aqualink (qty=4):
https://www.batterygiant.com/batteries/CR123A-T (must have solder tabs!)
--or--
http://www.interstatebatteries.com/1/1/4695-3v-1-55ah-lithium-cr123a-soldr-tab-lit0362.html

Batteries for RLB-35B (qty=3):
http://sepbatteries.com/lo26sx-saft-battery (must have solder tabs!)

Photos (Aqualink):
http://forums.sailboatowners.com/index.php?media/albums/acr-aqualink.3599/


NOTES: The Aqualink batteries were a cinch.

Photos (RLB-35B):
http://forums.sailboatowners.com/index.php?media/albums/acr-rlb-35b.3600/


NOTES: The RLB-35B batteries were tricky. They are wired with diodes and a fuse (that is why those diagonal strips appear). My solution was simple: Snip off the leads going to the old battery as close as possible to the old battery, and solder THAT end to the new battery. All the diodes and fuses where never un-soldered!

This is where everyone is going to say stuff like:

"How can you do that, this is a piece of safety equipment..."
"You must leave this to the experts..."
"It must be tested by a factory rep..."
"This voids your warranty..."
"These were never meant to be tampered with..."
"bla bla bla..."

My response is that ACR must be making a huge profit selling these cheap battery packs to ACR reps. That must be only reason why it costs so much for literally a 2 minute job. I know (or "hope") they test these units after replacing the batteries. So that must be it. I went through all the self tests, and all appears perfect. I even put my own, new expiration label on [grin]. 2020!

Thank goodness the quality of these units are so high that the rubber gaskets were still in perfect shape after 5 years.

No regrets.
No lectures please [grin].
 
Last edited:
Jul 25, 2007
320
-Irwin -Citation 40 Wilmington, NC
It's one thing to do risky things another to recommend to others that they do the same risky thing. Oh well this is a old battle. When you send your unit in for service they do more than just replace the batteries. They check all components, upgrade the software replace the seals and test the units on equipment that really checks output and frequency.
Personally I would not jump out of an airplane with a parachute I figured out how to repack myself with no training. But if you are comfortable with that go ahead and jump.....Geronimooooooooo
Me, if I am floating in the ocean alone hoping for help I will feel better knowing my equipment was professionally serviced but hey, that is just me.
 
Nov 26, 2012
2,315
Catalina 250 Bodega Bay CA
I personally think you did great! An inoperable EPIRB or no EPIRB is far worse than the one you carefully serviced and TESTED. Chief
 
Mar 11, 2015
357
Hunter 33.5 Tacoma, WA
It's one thing to do risky things another to recommend to others that they do the same risky thing.
It's just the batteries. One month ago, the unit was "considered" to be in perfect working order, and I have no doubt that if I needed it, it would have worked perfectly, even with the old software. The only difference is today it has a fresh set of batteries, and I KNOW it's good, cause I did it myself.

Also, I always carry 2 EPIRBs, one for the boat, and one when I leave the boat (hiking, etc.).
 
Sep 12, 2015
3
grady 30 Juno Beach
Photos (RLB-35B):
http://forums.sbo.sailboatowners.com/album.php?albumid=3600

NOTES: The RLB-35B batteries were tricky. They are wired with diodes and a fuse (that is why those diagonal strips appear). My solution was simple: Snip off the leads going to the old battery as close as possible to the old battery, and solder THAT end to the new battery. All the diodes and fuses where never un-soldered!
.
Good Job. I was in the process of doing the same. Just waiting for the batteries to arrive.
Agree. Four screws, one seal that seems to be in great shape (will put a little silicone grease on it to be sure). A simple connector and a bit of soldering. Bottom line is you can test the unit when you're done. BTW, mine had 3 amp 250V fuses and 1N5400 diodes but I plan to do as you did and just resolder and test. I did buy a bit of 70mm shrink wrap tubing to re-shrink over the batteries and new filament tape. I also plant to re-attach the label and re-date it so I'll remember.
 

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Mar 11, 2015
357
Hunter 33.5 Tacoma, WA
Good Job. I was in the process of doing the same. Just waiting for the batteries to arrive.
Agree. Four screws, one seal that seems to be in great shape (will put a little silicone grease on it to be sure). A simple connector and a bit of soldering. Bottom line is you can test the unit when you're done. BTW, mine had 3 amp 250V fuses and 1N5400 diodes but I plan to do as you did and just resolder and test. I did buy a bit of 70mm shrink wrap tubing to re-shrink over the batteries and new filament tape. I also plant to re-attach the label and re-date it so I'll remember.
When you cut the tabs as close as possible to the old batteries, take a pair of needle nose pliers and crimp the original tabs to the new replacement battery tabs, then solder. I did this back in May the the unit still checks out perfect. Good luck.
 
Sep 12, 2015
3
grady 30 Juno Beach
When you cut the tabs as close as possible to the old batteries, take a pair of needle nose pliers and crimp the original tabs to the new replacement battery tabs, then solder. I did this back in May the the unit still checks out perfect. Good luck.
good idea. will keep them together while soldering.
 
Sep 12, 2015
3
grady 30 Juno Beach
good idea. will keep them together while soldering.
Successfully replaced the batteries in my ACR EPIRB and shrink wrapped them with 70mm shrink wrap just like the original. Went on to 406link.com and registered for 2 day free trial, ran the self test and got e-mail back from satellite:

I'm OK - Beacon ID 2DCC442D5AFFBFF was detected on 24 Sep 2015 14:23:35 Z

Please do not reply to this email

so all is good! IMO, any DIY'er can replace batteries for fraction of cost AND test it afterward to confirm working.
 
Mar 11, 2015
357
Hunter 33.5 Tacoma, WA
Went on to 406link.com and registered for 2 day free trial
Awesome. I didn't know about this web site. I have two EPIRBs which I replaced the batteries myself, so I'll give it a try.

Great job!
 
Sep 25, 2008
1,096
CS 30 Toronto
I was told by the carrier it'll cost $150 to replace my Android smartphone battery. Found a youtube video to DIY. Parts $14.00 delivered to the door. Took a total 15 minutes. Phone is like new.
I am going to do the ACR next year.
 
Feb 8, 2014
1,300
Columbia 36 Muskegon
If you can find a battery for it. Phone batteries are readily available and knock offs (which is probably what you got) abound. Not so much with marine stuff, too small a market.
 
Aug 26, 2007
255
Hunter 41DS Ventura, California
Just ordered Panasonic CR123A batteries from Amazon- 12 for $20 with 2026 expiration. Thanks again for the tip.
 
Mar 11, 2015
357
Hunter 33.5 Tacoma, WA
Just ordered Panasonic CR123A batteries from Amazon- 12 for $20 with 2026 expiration. Thanks again for the tip.
Wrong batteries. You need the CR123A-T batteries, the one with solder tabs.
 
Last edited:
Nov 25, 2016
2
None None None
I'll add another data point to the discussion. I have a pair of ACS PLB-200s that are new in the box, but the battery expiration is 2013. The cheapest priced I found to have the batteries replaced is $125 per unit at several sources. Since I had nothing to lose, I opened the case of one of them to see what the batteries were. There are two, four-cell packs made up of GE/Sanyo CR123A batteries. (see photos)

I don't have the equipment for spot welding leads to CR123A cell, so I checked online for CR123A-T cells with tabs. I found GE/Sanyo cells for $3.25 each, for a total cost of $52.00 for the 16 I need, plus shipping: http://www.energexbatteries.com/products.php?product=CR123A%2dT. The tabs are long enough that I should be able to solder them directly together (with lots of surface area at the joints) and easily prevent any significant heat from reaching the cells. BTW, BatteryMart was over twice as expensive, at $6.75 each for the exact same cells.

Examining this unit, there is only one seal on the case and it's a pretty robust H-track. I don't see how it could be reassembled improperly and unless someone ham-fisted the screws and cracked the case, it's not going to leak after reassembly. So the bottom line is that I can spend $250 to have the batteries changed by someone (probably taking all of five minutes) or less than $65 for parts (with shipping) and a few minutes of labor to build new battery packs. The choice seems pretty straightforward to me.
 

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Last edited:
Oct 24, 2010
2,405
Hunter 30 Everett, WA
If you can solder, there is very little risk. From my experience I'm continually amazed at how many people think they can solder but can't. If it doesn't look perfect, stop.

Ken
 
Nov 25, 2016
2
None None None
Awesome. Nice shrink wrap for that professional touch. :biggrin:
Those are the original factory battery packs, so I can't take credit for the construction. However, I fully intend to build new packs that look - and function - just as good. Fortunately, I do know how to solder, so this will be a piece of cake.