I use a Santi system with Lola connections and battery pack. Its fantastic under my dry suit for 3 hour dives but I wouldn't bother using it for less than 3 hours planned. Also id be prepared for it to fail. Id never rely on it 100% because I have had so many issues mainly with the connections, and battery failure. A lot of people I know who use various heated systems have had issues. Possably modern systems are more reliable but as with most things once water and electrics are involved, there can be issues.