LiFePo batteries in checked baggage

On an upcoming United Airlines flight from the US to Europe, I’d like to carry 2 LiFePo batteries in checked baggage.

These also go by the designations lithium iron phosphate, LiFePo[sub]4[/sub], and LFP. They have little in common with lithium-ion or lithium-polymer batteries, but the dubious safety reputation of these and the similarity of the names can cause confusion.

Various Googling has produced little in the way on clear information. So I call upon the experience and wisdom of the SDMB.

The FAA is the final decision maker. You are totally correct that Lithium iron phosphate is a safer chemistry…but you don’t make the rules. The rules say lithium ion, which in general refers to a number of chemistries, including the one you want to bring :

Is the rule stupid? Yes, just like the one about electronics on during takeoff and landing, or airplane mode on wireless devices. Can you be arrested, fined, even imprisoned if you break the rules? Yep. Don’t do it. Stick them in your carry on.

I recommend using a capital O, unless you have some truly interesting chemistry there. Which TSA is unlikely to look kindly on.

As per the above, the shipping description is simply Lithium Iron, so the rules would be the same as other Lithium Iron batteries.

Is there any reason you can’t take it as carry on?

I’m not confident the TSA security check folks will understand these batteries.