Battery Life Tested

raymond6751 · 02-27-06, 08:48 PM

On my way out to patrol, from Kiel, I decided to test my boat and crew. Specifically, battery life and recharge times.

I had already done tests in a type VIIB, but this patrol is in a type IIA. I wanted to see if there were differences, and there were.

First, I ran at 'P' depth, 1/3 speed,until the charge was down to 50% which took 7 hours. This was the same in the bigger boat, but my speed in the little one was 4 knots. The type VII goes at 5 knots at 1/3 speed. Interesting.

Recharging the VII boat from 50% to full took 3.5 hours at 1/3 speed on the surface. I did a recharge in the type IIA in 6 hours and 20 minutes.

Next, I was interested in how long it would take to fully discharge the batteries and what would happen at that point. Would the lights dim and equipment cease to function?

My test ran from 7:15 AM to the 50% point at 14:14 hours, but I continued. At 49 minutes past midnight I got the warning that batteries were at 10%. By the way, at 25% my speed reduced from 4 to 3 knots. At the 10% mark my speed reduced again to 2 knots. My oxygen was now down to 50% at this point.

My engine RPM gauge showed only 10 but I was to discover that the boat could continue a very long time without further warnings. At 4 AM my speed reduced again to 1 knot but there was no change in the battery gauge.

Finally, at 5:36 AM I received the warning that oxygen was down to 25% and I decided to surface to save the crew. The batteries were still showing 10% at this time. To surface, simulating a battery failure by stopping engines, I hit 'E' to blow ballast and the 'S' ordering surface. We popped up nicely.

Nine hours later, running at standard speed, the batteries were fully recharged. By the way, my surface speed before testing was a smart 10 knots. While charging the batteries it fluctuated between 7 and 8 knots. This could have been wave or current action but I doubt this is modelled in the game.

What's the point? If you want to hunt along the enemy coast, it helps to know these things to plan your recharges outside of enemy air cover! I am sure each type of boat has different characteristics. Knowing your boat could save the mission.

02-27-06, 08:48 PM	#1
raymond6751 Admirable Mike Join Date: Mar 2004 Location: Canada Posts: 1,338 Downloads: 421 Uploads: 0	Battery Life Tested On my way out to patrol, from Kiel, I decided to test my boat and crew. Specifically, battery life and recharge times. I had already done tests in a type VIIB, but this patrol is in a type IIA. I wanted to see if there were differences, and there were. First, I ran at 'P' depth, 1/3 speed,until the charge was down to 50% which took 7 hours. This was the same in the bigger boat, but my speed in the little one was 4 knots. The type VII goes at 5 knots at 1/3 speed. Interesting. Recharging the VII boat from 50% to full took 3.5 hours at 1/3 speed on the surface. I did a recharge in the type IIA in 6 hours and 20 minutes. Next, I was interested in how long it would take to fully discharge the batteries and what would happen at that point. Would the lights dim and equipment cease to function? My test ran from 7:15 AM to the 50% point at 14:14 hours, but I continued. At 49 minutes past midnight I got the warning that batteries were at 10%. By the way, at 25% my speed reduced from 4 to 3 knots. At the 10% mark my speed reduced again to 2 knots. My oxygen was now down to 50% at this point. My engine RPM gauge showed only 10 but I was to discover that the boat could continue a very long time without further warnings. At 4 AM my speed reduced again to 1 knot but there was no change in the battery gauge. Finally, at 5:36 AM I received the warning that oxygen was down to 25% and I decided to surface to save the crew. The batteries were still showing 10% at this time. To surface, simulating a battery failure by stopping engines, I hit 'E' to blow ballast and the 'S' ordering surface. We popped up nicely. Nine hours later, running at standard speed, the batteries were fully recharged. By the way, my surface speed before testing was a smart 10 knots. While charging the batteries it fluctuated between 7 and 8 knots. This could have been wave or current action but I doubt this is modelled in the game. What's the point? If you want to hunt along the enemy coast, it helps to know these things to plan your recharges outside of enemy air cover! I am sure each type of boat has different characteristics. Knowing your boat could save the mission.