I bought the tattu 3cell, 11.1V, 1800mah battery and smart charger from flitetest. I set the charger to 1.8a, 11.1 V, 3 cell. I’ve charged it 3 times and this last time the battery swelled up like it was going to blow. Is 1.8a too much or is this just a defective battery?
First step is contact FT. If you haven't already, please invest in those lipo fire safe bags. Also, if this was the case, never ever leave a charging battery unattended. Not just run to the corner mart for some milk unattended. I mean do not leave the room in which the battery is charging. Otherwise, once a battery swells or gets "puffy" then take it to the appropriate hazard material site near you & let them properly dispose of it per regulation . People will tell you to just keep running it, it's not a big deal, etc., however, it is a big deal.
LiPOs are some of the most fickle batteries on the market & it's not worth trying to charge that thing again to risk a fire or put it back in your airplane & catch that on fire & ruining all of your other electronics with it or worse yet, injuring yourself or someone else. No one said hobbies are always low cost, but lipos are not part of our hobby that should be rigged & such to save a buck. The batteries come in boxes with very specific instructions on how to care for them & what do you in your very case. Sometimes it's trial & error to find the right battery/ESC/motor options that best fit your particular airplane.