Very cool, should see a significant weight drop from the deep cycle(assuming same capacity).
Not sure what the charger setup is on those but generally it's a good idea to keep them at about 90% charge or less if you're not going to be driving it immediately. LiIon doesn't like 100% charge or < 10% charge for more than a short period of time.
Do keep us updated, looking forward to seeing how it turns out.