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GPS or Tag product guide

Fi Series 3+ GPS Dog Collar and Tracker (FCB3), Size L

Medium and large dogs whose owner will keep a Fi membership running

The Series 3+ is an all-in-one cellular GPS collar with a stainless steel frame, IP68 rating, LED light and wireless charging. Fi states up to three months of battery life, which is unusually long for a cellular tracker. One month of membership is included and it renews after that to keep GPS service active, and part of the warranty Fi advertises is a membership benefit.

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Published specifications

  • Fi: cellular and GPS tracking; first month of membership included, then renews
  • Fi: up to 3 months battery life; wireless charging; charger and USB cable in box
  • Fi: industrial stainless steel frame, stated to handle 500 lb of resistance
  • Fi: IP68 and IP66K certified, claimed fresh and salt water to 50 m deep
  • Fi: modular sizing XS to XL; this ASIN is size L in blue; built-in LED light
  • Listing: model and part number FCB3; battery capacity 285 mAh; 2.72 oz

Fit and limits

Strengths

  • Fi states up to three months of battery, far longer than most cellular trackers
  • Stainless frame, IP68 and IP66K rating and wireless charging suit heavy wear
  • Escape Alerts, Lost Dog Mode and shared household access come with the app

Caveats

  • GPS service stops unless the membership is renewed after the first month
  • Neither document read publishes neck sizes or a minimum dog weight per size
  • Fi lists an extended warranty as a membership benefit, not a hardware term

The category and the catch: one month of service, then it renews

The Series 3+ is a cellular GPS collar, not a Bluetooth finder tag. The listing bullet says it runs on nationwide cellular and GPS coverage with no range limits, which is the behaviour you want if a dog can get genuinely out of sight. It is not the behaviour a tag can give you.

The second bullet states the trade plainly: the first month of membership is included, and membership renews after that first month to keep GPS service active. So the box price buys hardware plus thirty days, and the tracking stops when the membership does. We are not quoting any membership price here; get current terms from Fi before buying.

Fi's own membership page describes what the ongoing fee covers besides the cellular link: the app, multiple dogs on one account, unlimited users sharing access, customer service by phone, chat and email, and what Fi calls an extended warranty covering defects and malfunctions. That last item matters, because it means part of the warranty you may be relying on is tied to keeping the membership.

Battery: the number that sets this apart

Fi states up to three months of battery life for the Series 3+ on its collar page, and repeats it in the product summary on its home page. For a cellular tracker that is a long interval, and it is the clearest practical difference between this and the trackers that need charging every week.

The Amazon listing does not publish a battery-life figure at all. Its Features & Specs table gives a battery capacity of 285 milliamp hours and nothing else. If three months is the reason you are buying, take that figure from Fi's page and ask Fi what usage it assumes, because live tracking and Lost Dog Mode are the modes that drain any tracker fastest.

Charging is wireless on this model, which Fi lists among its features. That removes the exposed charging contacts that corrode on a collar worn in water, and it means the charger is a specific piece of kit rather than a generic cable. Amazon's Built-In Media field lists a charger and a USB cable in the box.

Build: stainless, IP68 and a claimed 50 metres

Fi describes an industrial-strength stainless steel frame and says the collar is rated to handle 500 pounds of resistance, which it frames as being for strong pullers and chewers. The Amazon bullet repeats the stainless steel frame and the IP68 waterproof rating.

On water, Fi goes further than the listing does. Its collar page says the product is IP68 and IP66K certified and describes it as resistant in fresh and salt water up to 50 metres deep. Fifty metres is a specific claim and Fi does not publish the test conditions behind it on that page, so treat it as the maker's statement rather than a verified depth rating.

There is a built-in LED light for night visibility, which Fi describes as colourful and the listing calls a built-in LED for dark walks. Both documents agree it is part of the collar rather than an accessory.

Fit: modular sizing, and what neither document tells you

Fi describes a modular design fit for XS to XL dogs and says the low-profile shape is made for 24-hour wear even on the smallest dogs. This ASIN is the size L version in blue, so the band is sized rather than universal, and buying the wrong band means a return rather than an adjustment.

Neither the Fi collar page nor the Amazon listing we read publishes the neck circumference range for each size, or a minimum dog weight. Fi does link a fit checker from its collar page, which we did not open. Measure your dog's neck and run it through Fi's own sizing tool before ordering rather than guessing from the letter.

Fi also advertises what it calls the Fi Puppy Warranty on the same page: swap the collar for free when the puppy is full grown. If you are buying for a growing dog, ask Fi what that swap requires and how long it stays available, because the page states the benefit without stating its conditions.

What the app does, and what Fi itself stops short of saying

Beyond location, the listing describes step counting, activity, sleep and rest tracking, and AI detection of behaviours including barking, licking, scratching, eating and drinking, with weekly goals and breed comparisons. Fi's collar page describes the same categories as movement and sleep, diet and hydration, and behaviours and habits.

The listing's own wording about what to do with that data is the sensible framing: long-term trends make it easier to notice quiet changes in routine that may be worth a vet conversation. We are not going further than that, and neither should a product page. A behaviour log is a record to discuss with a veterinarian, not a diagnosis.

Fi also advertises an AI Companion in the app that answers care questions and keeps vet visit and vaccine reminders, plus uploaded health records in one place. Treat an in-app assistant's answers the same way: something to raise with a vet, not to act on alone.

Locating a lost dog, and the warranty question to settle first

The two features aimed squarely at a dog that has actually got out are Escape Alerts, which fire when the dog leaves a safe zone you have drawn, and Lost Dog Mode, which switches to rapid live location updates. Fi also advertises Search Party, which it says alerts nearby Fi members when a collar is in Lost Mode. All of these depend on an active membership and on cellular coverage where the dog is.

On warranty, the documents point in two directions. Amazon's listing field says 1 Year Warranty and refers you to a separate warranty page. Fi's membership page lists an extended warranty covering defects and malfunctions as a benefit of membership rather than of the hardware purchase.

Those are not the same thing, and the difference matters if you ever let the membership lapse. Before buying, ask Fi in writing what the hardware warranty is for part number FCB3 on its own, what the membership extends it to, and what happens to cover if the membership ends. Keep the receipt either way.

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Primary sources

  1. Fi Series 3+ smart collar page, construction, battery and waterproofing
  2. Fi membership page, what the subscription includes

Primary sources checked .

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