I have yet to to see any
used free standing plastic housed unrestrained LiFePO4
prismatic cell more than a year old that does not exhibit some swelling. I have checked a few.
Mine are restrained by substantial stainless steel strapping and a steel ruler placed on any exterior long flat side surface reveals all. Concerned? Not at all. It is just evolution and expected except by a few doomsayers.
There is nothing and I repeat nothing in a typical RV charge/dishcharge setup that could ever raise lithium battery pack internals by more than a few degrees whether that pack is 100Ah or 500Ah under normal operating conditions. The tiny mΩ internal cell resistance dictates that.
A very serious and prolonged overcharge would have to occur without detection. We do all have some protection for that scenario don't we?
Significant swelling would be another matter regardless of battery chemistry. I have seen a few.
Those Trademe cells look perfect.
I will be placing my bid before lunch time tomorrow unless others get carried away.
Oops my $200 higher bid did not last long.