Introduction: Tack Tick RaceMaster Battery Replacement - $33

The Tack Tick RaceMaster is an electronic compass specifically made for sailing. It has dual displays so it can be viewed from either tack, is solar powered, and includes nice featues that calculate lifts and knocks, as well as a countdown timer. The unit is waterproof and very durable, but unfortunately the rechargeable Li-ion batteries inside eventually wear out from charge/discharge cycles. The manufacturer does not offer replacement services, and since a new unit retails for around $850, a self repair attempt seems justified.

To be fair, there are a couple other blogs that cover how to accomplish the repair, but I did not find them to be as complete as I would have liked, and they were not easy to find. Hopefully I can create something useful here.

This repair is not for the faint of heart or poor of eyesight. (I wore reading glasses)

In all seriousness, if you are not a fairly skilled electronic repair nerd, a local repair shop may be the best move. Just show them these steps!

Step 1: First, the Tools...

To complete this task you will need the following items. (feel free to substitute or improve)

  • 4 each replacement batteries, type MN2430-HZ1. I believe the originals were made by Sanyo, but the replacements were not. I was able to source them from Batteries Plus for US$5.99 each, plus a special order fee of about US$9. I would not recommend trying to make a more easily found battery work, there is not much room to work in under the LCD's.
  • A hair dryer or heat gun is used to make it easier to remove the strip of plastic that covers the screws on the back side of the unit. Not much heat is needed, and you don't want to melt it.
  • Some basic electronics bench repair tools (30W Soldering iron, lead/tin solder, copper braid, long pliers, sponge)
  • Some basic bench tools (small screw driver, pliers, knife, forceps)
  • Flash lights and lamps
  • A dab of Vaseline or silicon lubricant.
  • Silicone sealant (Optional, see last step)

I used a low power soldering iron so that I would make sure not to damage the board. I also used a flat tip, mainly because I was too lazy to change it. The de-soldering wick I used was copper braid 1.5 mm. Having some 3 mm around is nice for the larger hole, but not necessary.

Step 2: Ok, Lets Get Started...

The first thing to do is turn off the unit.

Next, use the hair dryer to warm up the back of the unit. Once it is warm, wedge the flat blade of a utility knife under the white plastic ring that covers the screws. Be careful, do not cut it. Wedge it up slowly using the back of the blade, not the sharp end. Slowly work your way around the unit and remove the ring. Set aside

Next, remove the 14 screws that hold the back in place. These are stainless steel, so don't lose any of them as it would be difficult to find replacements.

Once the screws are out, the back plate should come off easily. It just slides out.

Be careful not to lose the rubber ring that provides the water tight seal.

Step 3:

Remove the four screws that hold the circuit board in place. Save these separately from the screws that held the back plate in place, they may be different.

Once the screws are out, you need to disconnect the buttons flat flex cables from the circuit board. This is best done with a needle nose pliers, or something similar. Gently pull them straight out of the connector. Do not bend the ends, these need to be straight and firm for insertion during assembly.

Step 4: Remove the Assembly From the Housing.

Place your finger in the hole in the centre of the circuit board and remove it from the housing. Set the housing aside for now. Be very careful not the break or chip the LCD panels. I don't think those are replaceable, so that would mean game over.

Step 5: De-Solder the Original Batteries.

The first image above shows the 8 spots where the batteries are soldered into the board. (highlighted in RED)

The batteries are also attached to main board with some double-stick non-conductive foam, which makes things a bit more difficult.

Using your iron, heat up the large hole first and just wedge the battery away from the board. Once that is done, see if you can remove the foam using a needle nose or a long screw driver. Then, heat up the smaller hole which is the center post of the battery. Use care when removing all four batteries, and save the foam. Do not wedge them against the LCD panel as it may break.

Once removed, set the original batteries aside and stick the foam pieces on each of the new batteries. I tried leaving the foam on the board and working the new battery in to place, but in the end just took out the foam and stuck it to the battery. The foam is just a spacer to make sure the metal battery does not cause a short circuit on the main board. The second image shows one of the batteries removed.

After the batteries are removed, you may need to clean up the holes with de-soldering wick. If they are not clean, the new battery tabs may not fit.

Step 6: Insert the New Batteries.

There is not much I can tell you about this, you just need to figure out how to get the new batteries in place. Here are some tips...

  • Be patient. This takes time and it is difficult to see.
  • Shine a flash light through the bottom of the board in order to light up the area inside "The Cave" created by the two LCD panels.
  • Obviously, replace the deep ones first.
  • Clip away some of the leads on the batteries. I shortened the centre post, and made the edge post thinner. This made it easier to fit things into place.
  • Use a long pliers to manipulate the two that are deep in the cave. (1st image)
  • Once in place, the sticky foam will hold them to the board.
  • Make sure the foam is keeping the bottom of the battery from touching the circuit board.

Once a battery is in place, solder it with fresh solder. Depending on what your battery posts look like, you probably don't need to fill the large hole with solder. As long as the post is solidly connected to the pad (hole) it should be fine. If you try to fill the hole, you may drip molten solder on something important.

Step 7: OK, Time to Assemble.

Now that the batteries are replaced, Clean the LCD and the solar pane of any fingerprints and put the assembly back into the case. Route the cables as shown in the picture and press them into the black connectors using a flat pair of pliers. Make sure to have the cable aligned with the slot before pressing. You may hear it beep when you push it in, this is normal. Actually a good thing!

At this point, use the buttons on the front of the unit to test it. The new batteries should have enough charge to fire it up. If it does not work, go back and look for bad solder joints, or check those pesky cables...

Once all is working, Replace the 4 screws that hold the board in place.

Use some silicon lubricant (not silicone sealant!) on the O-Ring, or just some Vaseline, and replace the back plate. Don't forget to put the silica gel packet in, and be careful that it is all aligned and fitting perfect.

tighten the 14 screws in an alternating pattern. Go opposite ends, not around the horn. This will lead to even pressure against the o-ring and no leaks.

Step 8: Test Before Final the Seal.

boot the system up by pressing the On/Off/Mode button. The unit shows bAt while doing a battery test, and then the results of the test. Ours showed 180 h , which was impressive. Time will tell how well it works, but for now that looks pretty awesome! Check all 8 buttons to make sure they respond.

Step 9: Finally, Seal It Up.

I think this step is optional, and I may regret it in the future. I wanted to make sure that no water could seep past the screw holes, so I used silicone sealant to attach the plastic ring to the back. I dabbed a bit of goop onto each screw as well. I know this will make it very difficult to get back into the unit if we ever need to replace the batteries again, but I guess I will cross that bridge when I come to it. Hopefully that is 10 years from now.

Step 10: Thanks, and I Hope This Works for You

Thank you to my Son, Jacob, for helping me with this project. It really helps to have an extra set of hands when you are putting the batteries into the unit.