Personal Locator Beacon Battery Life ?

[peakbagger]

As part of the changeover of my seasonal gear in my pack, I check my PLB batteries. I have McMurdo Fast Find 220. It is one of the lighter GPS enabled beacons out there. Despite a battery expiration date on the case of 2019 when I perform a self test it is still reading a high state of charge for the battery. Per the instructions and self test it still has got plenty of juice. Anyone else with a PLB ever needed to do a battery change out yet.?.

These were effectively a throw away when new as the cost to ship it back and get the battery replaced and the unit recertified was about the cost of the new one. There are now a couple of sources of 3rd party battery packs for far less or even the option to DIY as the cells are standard lithium camera batteries. There are several videos on you tube on how to do it. These are marine grade units that require up to date certification, so they tend to be overbuilt for hiking use, I keep mine buried in the pack in double ziplock so not that worried about salt water.

[maineguy]

A PLB is an item of last recourse. It absolutely has to work when you flip the switch. If the self test is just a check on the voltage, the battery could still be below specs (Ah wise) but indicate OK. Why not just change the batteries for peace of mind?

[DougPaul]

PLBs use lithium primary (non-rechargeable) batteries which have a nominal shelf life of 10 years. (Batteries carried by hikers go through temperature swings and ranges that can potentially shorten the shelf life.)

IIRC, the regs require PLB batteries to be replaced every 5 years by a certified repair shop or the manufacturer.

Lithium primary batteries have a very flat discharge curve (ie the voltage stays constant over a wide range of states of charge) so it's very difficult to determine the amount of charge left.

Doug

[skiguy]

PLBs use lithium primary (non-rechargeable) batteries which have a nominal shelf life of 10 years. (Batteries carried by hikers go through temperature swings and ranges that can potentially shorten the shelf life.)

IIRC, the regs require PLB batteries to be replaced every 5 years by a certified repair shop or the manufacturer.

Lithium primary batteries have a very flat discharge curve (ie the voltage stays constant over a wide range of states of charge) so it's very difficult to determine the amount of charge left.

Doug

Excellent info!