Submerge Scooters Background and History Motor types Lithium batteries
2000 Submerge Scooters is born and starts using Tekna/Oceanic brushed motors and prop/shroud technology, which was originally developed in early 80's with Cray supercomputers. Submerge- Pioneer of single handle/motorcycle style handle for tow behind scooters (Now industry standard). UV-18, UV-26, UV-42 lead acid models. 2003/2004 Submerge experimental Nickel Metal Hydride scooter achieved world record cave dive in Brazil. 5x F cell packs into a UV-42 scooter. 60 A/h (1500 Watt/hour), 6 hour runtime. 2004 Submerge- first production NiMH scooter in the USA. SAFT F cell pack with 28 A/h and 2 hour run time in a UV-18 scooter. 2006 Introduction of exclusive, Submerge brushed motor. Introduction of N-19 scooter, lightweight model with 2D NiMH pack, 20 a/h (up to 450 Watt/hour) Experimental Lithium Polymer scooter. 80A/h (2000 Watt/Hour) in a UV-18 scooter. 2010 MAGNUS 950 Introduction of Brushless motor, Electronic speed control and LIPO batteries
1990's 1980's 1 Depth rating: 40 meters Runtime: 60 minutes Weight 23 Kg
2006 Depth rating 120 meters Runtime 60 to 90 minutes Weight 22 kg
Submerge brushed motor introduced in 2006
Brush board features: Elimination of all soldered connections Elimination of contact connections between individual brushes and the brush board. Replaced by welded connections. Result: Capable of higher power Lower operating temperature Extended service life
New, unused Submerge brushboard 3 year old Submerge brush board 400 dives/400 hours No significant wear. Minimal carbon accumulation in motor
Armature design features: Machine wound for winding uniformity, resulting in very consistent motor performance, balance and reliability. 316 stainless steel shaft for Optimum corrosion resistance Shaft diameter increased 33% (to 1/2 )Between bearings for improved rigidity and smoothness.
Integral engine cooling. -Aluminum tail cone acts as a water cooled radiator. Water flows Over tail cone creating efficient heat transfer -Brush board and commutator housed inside aluminum tail cone -armature extends into tail cone -Field frame attached to tail cone -Skew on armature promotes air Circulation past the water cooled tail cone
Breakdown of MAGNUS motor and Submerge brushed motors
Brushless motor windings around frame Brushed motor armature attached to shaft.
Simple brushed motor control Vs Complex electronic speed Control in brushless motors (on left)
Brushed motors are very efficient if well designed and implemented DPV's are a perfect application for brushed motors: DPV's most often used at or near full load, where brushed motors are most efficient. Simplest possible control system with zero electronics. Low RPM motors (<1000 RPM) have very little brush wear; require no significant maintenance. Allows full power start up's However: Unless electronic speed control is used, brushed DPV motors are not efficient running at less than 75% power. Brushless motors, if well designed and implemented can be 5% to 10% more efficient than fixed RPM brushed motors running at peak efficiency Due to windings on external housing, brushless motors can be run with more power, limited only by the efficiency of heat dissipation. Brushless motors do not save much weight; a 3 Kg Brushless motor will not be as efficient or powerful as a 5Kg brushed motor. Brushless motors are very reliable but the required complex electronic speed control can fail; overall the simple brushed motor is more reliable (no electronics) 5X more performance can be gained by switching battery technology than switching motor technology.
250 Battery chemistry: Watt/Hours per Kg 200 150 100 50 0 Lead Acid Nickel Metal Hydride Lithium Ion Lithium Polymer (LIPO) Lithium Iron Phosphate
Practical example of battery technology potential: UV-18, 70 pounds/32 Kg 6 hour runtime 7 6 5 4 3 hour runtime 3 2 hour runtime 2 1 hour runtime 1 0 Lead Acid Nickel Metal Hydride Lithium Polymer (LIPO) Lithium Iron Phosphate
LITHIUM batteries Cobalt Most commonly used Eg 18650 cylindrical Generally referred to as Lithium Ion Manganese Nickel Cobalt Iron Phosphate (LiFE) Manganese Lithium Ion Polymer LIPO Cylindrical Metal cells
Lithium Ion 18650 cell LIPO cell 10A/h
Lithium Ion Lithium Ion Polymer LIPO
1200 Cycle Life 1000 800 600 400 200 0 Lead Acid NiMH LIPO LIFE
Lithium iron Phosphate cells offer the best cycle life but are almost double the size and weight of other types of lithium batteries, making them unsuited to reducing scooter size and weight. Ultimately Iron Phosphates are only marginally better than Nickel Metal Hydride batteries in reducing scooter size and weight. They are particularly suited to use in the larger format UV scooters where they can double runtimes without the shortcomings of nickel metal hydride cells. LIPO type Lithium Iron Phosphate 25 volt 10 a/h 8 cells, 3.2 volts per cell LIPO Lithium Cobalt 25 volt 10 A/h 7 cells, 3.6 volts per cell
More electronics... Lithium Battery pack Battery Management System (BMS) Some Functions: Cut off charger if any cell exceeds safe voltage Cut off discharge when any cell reaches low voltage limit Balance cell voltages to within acceptable limits Limit maximum discharge current
Scooter development due to battery technology 200 180 160 140 120 Weight lbs Runtime (Min) 100 80 60 40 20 0 UV-18 UV-26 UV-42 N-19 UV-N-37 MAGNUS
Most safe Most safe Iron Phosphate Lead Acid Manganese/Nickel/Cobalt NiMH Manganese/spinel Cobalt Lithium Least Safe Least Safe
Key features: Fastest scooter Most efficient Longest range 1000 Watt brushless motor Electronic speed control Speed with double 18L cylinders: 35 to 77 Meters/Minute Endurance 60 to 360 Minutes Range with doubles/rebreather 5.6 to 16Km Weight 24Kg Lithium Polymer (LIPO) batteries (Nickel/Manganese/Cobalt)