In America I was a reseller of the stuff. We used it in Boats as I was employed for 35 years as a field Rep and Team Driver for Mercury Marine, Started back under Carl K. was hired before I enlisted in the USAF. Had a job waiting for me if I returned from Vietnam (Thailand) if I wanted it. We used Nitrous to propel a 15' Boat with a Mercury V6 from a standing start thru 1/4 Mile in 6.3 Seconds at 147 mph (The boat was a 15' Kevlar V Hull Checkmate) So light two men could easily lift Hull without motor (motor was 4x weight of hull) off trailer.
Reason I wrote you was to stop Battery drain. Install 2 Primary relays (ones with 2 sets of contacts and use both sets!) and diodes. Insure that tank valve is power to open thru relay not straight from Battery. This way valve or system has no Voltage connection until relay is energized and both sets of contacts are closed. use one set for negative feed from Battery, not frame ground. The other is for Positive connections. Your battery drain is from the Negative lead back to battery!
Worked for us for 5 years and 7 different Engines from BP stacker thru Mod VP and OZ Engines as long as we kept Engines together never had a Electrical issue.