EPIRB Servicing FAQS

Why is it so expensive?

Why can't I do it myself?

My EPIRB passes its sef-test.  Can I leave it for a year or two?

Is it better to buy a new one?  PLBs are much cheaper!

Why should I use Sartech?


An EPIRB is never used, except in an emergency. Unlike your boat instruments or your VHF radio, you will never know if it is not working until you really need it. Self-test functions give a good indication that all is well, but they are not infallible. So once in 5 years it is important to do more than just swap the batteries.

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Changing batteries in an EPIRB is not rocket science. Given the necessary spare parts and instructions, any competent person could do it. However there are risks involved in handling high rate lithium primary batteries, and there is also a worry that the beacon could be damaged and fail to work in an emergency. Sensitive electronics can be damaged by static electricity, for example, and the failure may not occur for some time afterwards. Very few beacons have been designed for user battery replacement, with separately sealed battery packs that avoid any danger of damage to the beacon electronics. The McMurdo Fastfind & Fastfind MAX PLBs are an example of this (N.B. not the later Fastfind 200 series).

The newest EPIRB models use battery packs made up from small camera cells which are available in the shops, but most EPIRBs in use today have battery packs made up from large primary lithium cells (typically "D" size) which have the potential in the wrong hands to cause a serious fire or explosion. It is particularly dangerous if well intentioned engineers get hold of these cells and try to make them up into battery packs by soldering them together. This should never be attempted. Properly assembled lithium packs use resistance welded nickel connecting strips, and electronic fuses to make them safe even if accidentally short circuited.

Even experienced marine electronics service engineers are not approved to carry out EPIRB battery changing until they have attended a training course, and acquired a minimum level of necessary test equipment.

EPIRB batteries gradually lose their stored energy over time. A small amount is lost every time the TEST button is pressed, however the biggest loss is through "self-discharge". You will be familiar with this effect if you pick up a torch which has been left in a drawer for a year or more. Most likely it will be very weak or completely dead. Lithium batteries hold their power very well, but give no warning of their impending demise. Unlike alkaline batteries used in torches, their voltage drops off very rapidly at the end of life, so that they will deliver full power (and pass the self-test) right up to the last few minutes. So pressing the TEST button can give no indication of the remaining capacity.

Up until the expiry date marked on the EPIRB, then you can be very confident that there is sufficient capacity remaining in the battery to power the EPIRB for 48 hours at -20degC. However even this period is no more than an estimate, as the battery self-discharge is highly temperature dependent. An EPIRB which spends a lot of its time at 30 degC will lose capacity twice as fast as one kept at 20 degC. At 40 degC, the self-discharge doubles again.

So in conclusion, if your EPIRB is kept in a warm climate, you should certainly make sure it is serviced before the expiry date is reached. In a cool climate, there is less of a worry, and you can get the job done at the next convenient time - e.g. during the winter season. But don't leave it too long, or you might find that more time has passed than you thought, and you will regret it once you are in that life raft!

Like most electronic products, the technology moves on, and the latest EPIRBs are probably half the size half the cost of those bought 10 years ago. The older EPIRBs use bigger batteries and cost more to service. So you should consider the service cost compared to the cost of a new EPIRB. Most likely it will be economic to get your EPIRB serviced after 5 years, but at 10 years the economics may point ot upgrading to a new one - especially if you are attracted by new features such as integrated GPS, or the smaller size makes it easier to mount on your new boat! We offer a £50 trade-in discount against certain new models which can tip the balance on this decision.  Think carefully before deciding to replace and EPIRB with a cheaper PLB.  PLBs are made smaller to make them easier to carry, but they must be manually activated and held out of the water.  They have half the operating time, and some do not even float!

We have been servicing EPIRBs and SARTs since 1992 and are undoubtedly the world's leading independent supplier of lithium batteries and test equipment for these products. We are a UK MCA registered shore-based maintainer for EPIRBs and carry out all our maintenance in accordance with IMO Guidelines. Our QA system is approved to ISO9001:2008.

Sartech is an approved service centre for all leading brands, using original spare parts and with access to service bulletins and the latest software updates 

ACR approved service centreGME Approved Service CentreKannad Marine Approved Service CentreMcMurdo Approved Service CentreOcean Signal Approved Service Centre

We carry £5,000,000.00 Product and Public Liability Insurance.

And above all, we are nice people to deal with!

"thanks for a quick turn around - good service"

" I just wanted to thank everyone at Sartech for the outstanding service. From our first contact through to receiving the returned, serviced unit everything was conducted in a speedy, professional and thoroughly impressive way. These things don’t happen unless the ladies and gents who are involved are good at their jobs and actually care about getting things right, so please pass on my appreciation and good wishes."

 "special thanks to you all at Sartech for such a prompt service in returning my PLB fully serviced with a new battery"