I’ve just merged this thread with another one on same topic, so if you read back a bit you will find some info.
It is not difficult to do but some housings are glued together and are messy to open without major damage.
Do you need to test it afterwards? Would it lose its config by a momentary battery disconnection? If so, use this method.
At least one PLB model (sorry, don’t remember which one) uses lithium thionyl chloride batteries. The only well-known manufacturer of these is Tadiran.
Hi @PeterPeter
I have exactly the same ELT, did you measure the voltage with some load? I was thinking of maybe 500 mA?
27-Dec-22 16:5307
Just measured the battery in my post above and it is 12.75V. It was 12.6V a year ago so I am making money
I will do, but is 500mA representative? That’s 6W.
EDIT: 11.3V across a 24R resistor.
One snag with home replacement is that many cells available to consumers are fakes and it is very hard to tell although looking for spelling errors on the label may help. Certainly buying from reputable dealers offers little protection and so some sort of capacity test on a sample is really essential. Testers are readily available but still won’t speak to self discharge and shelf life.
This problem is greatest with cells also used in vapes consumer products and decreases with more specialised parts, but I can see why the PLB manufacturer wants to play safe because the ‘20 yr’ claim may well be stuffed full of weasel words in the small print. And the leakage current in a device controlled by an electronic switch rather than a relay may vary…
Sure; IMHO the majority of branded batteries on Amazon and Ebay are fakes. For example you can buy Yuasa for 1/4 of the cost of the real one. This is why Bezos is so rich: he sells mostly chinese crap (actually it is very hard to sell anything via Amazon that isn’t such) 
At some point I will open up the battery pack, like @nuccio did above and change the batteries myself. I will need to get batteries with solder tags, and that immediately implies a specialist and non-cheap product.
I might also measure if there is a quiescent current draw
I think this battery replacement business is a huge con
