The Transponders we use are a sealed unit. This keeps the moisture out and makes them reliable.
You can normally expect to get at least 5-7 years from your transponder without any issues from low battery. Fortunately, the MYLAPS Orbits software we use alerts us when the battery is getting low. We are finding that we can get another 6 Months or so, from a Transponder once the “low Battery” warning appears. The risk is that one or more of your laps may not be recorded. If the speakers at the startline or start caravan are indicating whenever a crossing is made, the officials may pick up you did not get a “read” and insert a manual crossing for you.
To get more life out of your Transponder, it is possible (with care) to replace the battery. I should mention that it is risky and you may end up with a small plastic brick!
There are 2 types of Transponder available.
- A “Flex” (Lease) transponder. These are ‘activated’ for 1, 3, or 5 years. The cost $15 + whatever lease period. If they breakdown or go flat, MYLAPS replace them free of charge.
- A purchased transponder. These used to cost ~AU$140 and last as long as the battery. The battery is only really used when you cross the start line. They are however in that ‘turned on” state whenever they are close to the start line. #Tip – keep at least 3m away from the start line when you are not racing.
1- Use a dremel or other cutting equipment to carefully remove the potting mix to expose the battery. I routered a hollow in a piece of wood to serve as a jig to hold the transponder.
I then used a drill press to help guide me in. I also setup a vacuum to extract the dust so I could see what I was doing
2- Once you have the battery exposed, use a knife to carefully pry the top terminal and release the 2 spot welds.
3- Dig into the edge of the battery and prize it up. Be careful as you don’t want to break the bottom terminal. The bottom terminal goes in the opposite direction to the top terminal, so prize from that end
4- Trim the terminals so they cannot touch each other. At this point, maybe hook up a battery and test the transponder across the start line (may as well know it it works before continuing)
5- Solder on a couple of wires, allowing a little extra to curl up under. Solder on a battery holder. Pay particular care to correct polarity.
6- Make sure when the battery holder is in the final position, there is no chance of a short circuit. Fill the cavity with silastic (use a neutral cure version, not acid cure)
7- A spring clamp works well to hold it while curing overnight
8- Remove any excess silastic that oozed into the battery holder. You are now ready to use replaceable batteries.
9- I believe you should test the Transponder across the start line as soon as possible. This makes sure it works and also cycles it through “on” and “off” states. We have seen batteries go flat quite quickly and are thinking it was to do with how the Transponder first powered up and stayed in an “on” state (just a theory).