You don't still have the modules that swelled hooked up do you?!?!
That ain't safe, even when not using the cart! Read through this thread:
http://www.buggiesgonewild.com/lithi...-exploded.html
To be clear, this was not a Leaf module battery pack, that caught fire. It was a Volt battery pack. However, in this thread good information is shared about lithium batteries, be it Leaf, Volt or others.
Maybe give us some specs on your components and pictures of your setup. The gurus on here will be able to give you advice.