When a TT15/T5 collar flashes red on charge, or fails to power on, it could be a possible indication that the battery is defective. If you see this occur, immediately take down the collar's serial number and give DU a call to check warranty status if you are at all unsure about the collar's age. If under warranty, get the collar swapped out immediately and be done with it, and absolutely do NOT take apart the collar, as this will void your warranty. However, if you are out of warranty, there is no harm in removing the screws and back plate, and attempting to test a new battery in the malfunctioning collar.

A replacement on a TT15 collar typically runs $185, however a replacement battery normally costs $35-$60, making it much more cost effective to replace the battery if possible. After connecting another battery, if your unit fires up and begins to track perfectly, you've found the problem. It's recommended to have a spare battery on hand for situations like this, or so you can conveniently test a non-working collar's power supply.


For this example, we'll be looking at a full-sized collar, however the process is essentially the same on a TT15 mini. To start, use a screwdriver to remove the collar's screws and back plate. Each collar has 8 screws in total, with the middle screw being the shortest. The only screws that need to be removed to inspect the battery are the longer outside screws; the middle screw does NOT need to be removed to replace the battery, as it simply holds the back plate to the collar. Also remember when replacing screws, ensure that all 8 are in the collar, or water damage could occur. Using different screws or the wrong size can allow water inside and cause corrosion, rust, or damage to the motherboard.


After removing the screws and pulling off the battery cover, you'll see the motherboard (1), gasket (2), battery cover (3) , and connector ports (4)

If the Garmin logo is facing you, the connector on the left will be the one for the battery.

This particular collar has water damage, possibly due to the blue silicone gasket being out of place, and the wires on the battery connector have corroded away. After removing the connector ports from the motherboard, your collar should look like this

The battery is housed inside the silver casing, so to remove the old battery we will need to take the three screws out that are surrounding it.

Now that the screws are out, just lift off the housing and remove the battery.

To put in a new battery just follow the same procedure as the removal, start by placing the new battery in the collar and make sure that the wires from this battery are on the same side as the ones that are attached to the collar. Then replace the silver casing and put in the screws. Reattach the wires to the motherboard and test your collar. Remember when putting your collar back together that the rubber gasket is placed back on the seal and the outer screws go into their respective locations.


You can simply test the battery by unplugging the connector from the board to the battery, and replacing it with another one from a working collar, or a spare battery if you have one already loose. Press the power button to test the collar once your new battery is connected. If it failed to power on before and now powers up, your battery was the issue and a new Lithium-ion Replacement Battery Pack for your TT15, TT10, or T5 should solve the problem.

And remember, if you ever need help with any step along the way just call Double U and we can help walk you through it!