sub batteries

[Roger Dodger]

S-Boat (Group I)
Propulsion: 2 x New London Ship and Engine Company (NELSECO) diesels, 1,200 hp (895 kW) each
2 x Electro Dynamic (S-1, S-30-S-35), Ridgway (S-18, S-20 through S-29), or General Electric (S-36 through S-41) motors, 750 hp(550 kW) each
120 cell Exide battery
two shafts
Speed: 14.5 knots (27 km/h) surfaced; 11 knots (20 km/h) submerged
Range: 5,000 miles (8,000 km) at 10 knots (19 km/h) surfaced
Submerged Range/Endurance not found

Gato Class
Propulsion and power:4x diesel 5400hp
4x electric motors 2740hp
2 × 126-cell Sargo batteries
2 shafts
Speed:
Surfaced:20.25 design/ 17knots operational
Submerged:8.75knots
Range:
Surfaced:12,000nm at 10knots
Submerged:95nm at 5knots
Endurance:48 hours at 2 knots (4 km/h) submerged
75 days on patrol

Source: http://en.wikipedia.org/wiki/List_of...ed_States_Navy

Given the above specs, I would expect the S-Boats to have 1/2 the endurance submerged and take twice the time to fully re-charge its (single) battery compared to the Fleet Boats.