A Personal Locator Beacon, or PLB, is a small satellite communication device used to signal for help in an emergency. Unlike EPIRBs, which are registered to a vessel, PLBs are registered to a person. You can take it with you wherever you go, whether you are sailing, hiking, or just going for a drive.

I am currently planning on buying my next PLB, which got me wondering just how long I can expect my PLB to last before it needs replacing? After quite a lot of research, I have managed to find the answer.

A PLB will last for 5 years in standby mode or 24 hours in operational mode. Your manufacturer will tell you the battery life and expected operational time of your PLB. Battery lives range from 5 to 7 years, and operational time ranges from 24 to 35 hours.

When determining how long a PLB will last, it is important to clarify exactly what you are asking.

Typically, people are interested in knowing how long the PLB will last before it needs to be replaced.

You can find this by looking at the battery life of the PLB. Once the battery expires, it needs replacing by an authorised service agent. Given the cost of replacement and continuous advances in technology, most people take the opportunity to replace the PLB once the battery expires.

There is a caveat that an activated PLB needs to be replaced after use.

The other question commonly asked is how long the PLB will last once activated.

You can find this by looking at the operational life of the PLB. The figure will be given in hours and tells you how long you can expect the PLB to be able to transmit for.

Both operational life, and battery life do vary by model and manufacturer, so in both cases, it is important to check the documentation that came with your PLB.

How long does a personal locator beacon last when activated?

If you find yourself in a life-threatening situation, you will activate your PLB.

At this point, you want to know that your PLB has enough power to last from the moment you activate it, until the moment you are rescued.

Unlike EPIRBs, PLBs are not as standardised across different manufacturers. In the table below, I have listed the operational life of a selection of PLBs from some of the most popular manufacturers.

PLBOperational Time
McMurdo FastFind 220 PLB>35h
Ocean Signal RescueME PLB1>24h
ACR ResQLink 400 PLB>24h

*Table data from force4.co.uk, accessed 04 Feb 2021.

You can see that they all have an operational life >24 hours, but the McMurdo FastFind 220 PLB has an extended operational life of >35h.

Manufacturers have given a minimum operational time because the precise time will vary according to a number of conditions. As such, you can usually expect performance in excess of the minimum stated times.

For example, as the PLB nears the end of its battery life, you can expect the operational time to be closer to the minimum time due to the slow discharge of the battery over time.

Additionally, factors such as temperature will also have an impact. Manufacturers publish their operational temperature range, and you can expect battery life to be optimised towards the middle of that range.

In general, a good assumption with PLBs is that once it has been activated, you can expect to have at least 24 hours of operational time.

What is the battery life of a personal locator beacon?

Arguably more relevant for a normal user is the expected battery life of your personal locator beacon.

The battery life determines how long you will be able to rely on your PLB before needing to replace the battery. As the battery needs to be replaced by an authorised service agent, most people use the battery life of their PLB as the trigger for its replacement.

Given the advances in technology over the typical battery life of a PLB, in my opinion, it does make sense to replace your PLB at this point.

The battery life of a PLB varies by manufacturer. In the table below, I have listed the battery life of three of the most popular PLBs at the time of writing this article.

PLBBattery Life
McMurdo FastFind 220 PLB6 years
Ocean Signal RescueME PLB17 years
ACR ResQLink 400 PLB5 years

*Table data from force4.co.uk, accessed 04 Feb 2021.

You can see that they are all different, ranging between 5 and 7 years.

Interestingly, manufacturers usually offer their warranty to cover the same period of time as the expected battery life.

In general, a good assumption with PLBs is that you can expect the battery life to be around 5 years.

When does a personal locator beacon need replacing?

While there may be many reasons for replacing your PLB, there are two that means replacement is essential.

Pro Tip:

When I talk about replacing your PLB, there is always the alternative to have the PLB serviced by an authorised agent. The cost difference vs the huge importance of the PLB means that I usually recommend a replacement rather than a service though.

You need to replace your PLB once the battery expires

Once the battery reaches its expiry date, the manufacturer no longer has confidence that it will perform as required in an emergency.

Statistically, most PLBs will still work after their expiry date. Unfortunately, there is no guarantee that yours will.

The whole reason to carry a PLB is for peace of mind that you will be able to summon help in an emergency. An expired PLB will not give you that peace of mind, so it is important to have it replaced so that it performs as you expect.

You need to replace your PLB after it has been activated

No matter how short the activation was, once you activate your PLB you must get it replaced.

There might be a circumstance where you activate your PLB and are rescued an hour later. You might think that you still have 23 hours left, so may as well keep using it.

In actual fact, the process of activation has interfered with the normal standby mode of the battery. You have drawn a lot of power from it compared to being in standby. There is no telling how that will impact the PLB in the future.

By this point, the PLB has already saved your life once. Investing in a new one shouldn’t be a tough decision to make.

Can you use a PLB more than once?

You cannot use a PLB more than once. An activated PLB must be replaced. Once it has been activated, you have drawn significantly more power that would normally be consumed in standby mode. You have no way of knowing how much power remains.

Should you replace or service a personal locator beacon?

When it is time to replace your PLB, you need to decide between servicing the PLB or just purchasing a new one.

The decision will often come down to cost.

It is probably cheaper to have your current PLB serviced and returned to you with a new expiry date.

For me, I usually recommend a replacement though.

The reason for this is that PLBs are usually designed to last at least 5 years. During that time, regulations may have changed or technology may have advanced.

For example, there are PLBs for sale that utilise Galileo in addition to GPS for fixing your position. They were not available a few years ago, but offer a significant upgrade over GPS alone.

Given the price of PLBs, and the fact that it is an insurance policy for your own safety, it makes sense to invest a little more in buying a new one every 5 years.