Battery charging is spot on!!!

pythos · 07-31-07, 09:37 AM

I had just finninshed one attack wave on a convoy off of Japan. It is late 42 and I am in command of a Tambor class boat.

Following the attack and run away, I am parelleling the convoy's last known course. At first I was going at full speed. I checked my battery level and noticed it was charging really slowly if at all, so I dropped to standard (still about 12 knots), and saw a small jump in the charge rate, then out of curiostiy I dropped it down to 2/3 (or the step below standard) and saw a bigger jump. Then it dawned on me.

The devs did their homework, just like they did with SH3.

With the German boats for battery charging one engine was dissconected from the prop shaft, and left connected to only the generator, leaving one prop stopped or "windmilling". This was simulated in Sh3 quite well.

With SH4 the same is done with the 2 engined/ direct drive S-boat. When charging one prop is stopped.

Now the newer fleet boats had four engines, none directly connected to the drive shafts, instead they were connected to a generator which in turn was connected to either the batteries, or directly to the drive motors. When traveling at slow and charging the boat would be proppelled by one or two engines, while the other two or three would charge the batteries. At standard it was two engines connected to the motors, and two to the generators. Then at full three driving one charging. At full all four would be driving, with a little bled off for charging, and at flank, no charging.

In SH4 this is simulated quite well. You will also notice there is no increase in speed when the battery indicates fully charged, like you get with the older or german boats. Also, while charging both propellers are turning.

I have to say, I am impressed.

SteamWake · 07-31-07, 11:41 AM

Are you saying that the batterys recharge faster when the helm is set to 2/3 in lieu of flank ?

Seems a bit counter intuitive.

tater · 07-31-07, 11:49 AM

Well, when surfaced you'd expect them to run all engines. If you want the boat to move at 1/3 speed, the other engines would be charging until the batteries were topped.

It's a little odd, there should be a difference between when you click the recharge batteries or not button. If set to recharge, I'd assume all engines would run, and any power produced NOT used to propel the boat at the ringed up speed would charge.

When the button is off, I'd expect the boat to only run as many diesel engines as needed to produce the power needed for the ringed up speed. If you have the boat set for 5 knots, I'd expect one engine running I think.

tater

SteamWake · 07-31-07, 12:07 PM

Well in the boats where an engine is dedicated to charging duty it (that engine) would charge at whatever rate it was set for.

The speed of the other engine would be irrelevant.

I do know that diesel engine generators are controlled to run at a constant speed and adjust throttle according to load to maintain that speed. However that is because they have to produce a consistant 60 cycles per second regardless of load. In order to charge batteries the alternating current would have to be converted to direct current so that cycles per second would not be critical and basically the faster you can spin the generator the more 'juice' you can get out of it.

pocatellodave · 07-31-07, 12:19 PM

I have been having a hard time with fuel conservation,but I'm doing much better now thank to a lot of help from other skippers.I use the Strict range mod,and this gives me nine knots at ahead standard,and it is the most efficient speed for mileage.I try to stay on the surface as much as possible,with battery charging off when applicable.My greatest wish would be that we skippers could determine the number of engines we wished to run on,and charge batteries.I'm pretty sure I read where skippers would run on only one engine to conserve fuel.Please someone correct me if I'm wrong.I know running with two engines for propulsion,and charging with two was S.O.P.Maybe a mod like I mentioned isn't out of the question.I thank all the people that gave me a hand with using fuel more frugally.
Pocatellodave

Tom C · 07-31-07, 03:49 PM

Quote:

In order to charge batteries the alternating current would have to be converted to direct current ...

I read somewhere, FleetSubmarine.com I think, some comments suggesting that WWII diesel-electric surface ships had DC/AC converters but submarines did not, all-DC. Does anybody know for certain?

Sailor Steve · 07-31-07, 04:22 PM

This would indicate that the motors and generators were all DC.
http://www.maritime.org/fleetsub/elect/chap1.htm#1F

07-31-07, 04:22 PM	#7
Sailor Steve Eternal Patrol Join Date: Nov 2002 Location: High in the mountains of Utah Posts: 50,369 Downloads: 745 Uploads: 249	This would indicate that the motors and generators were all DC. http://www.maritime.org/fleetsub/elect/chap1.htm#1F __________________ “Never do anything you can't take back.” —Rocky Russo

07-31-07, 09:37 AM	#1
pythos Grey Wolf Join Date: May 2005 Location: Somewhere over there Posts: 834 Downloads: 46 Uploads: 0	Battery charging is spot on!!! I had just finninshed one attack wave on a convoy off of Japan. It is late 42 and I am in command of a Tambor class boat. Following the attack and run away, I am parelleling the convoy's last known course. At first I was going at full speed. I checked my battery level and noticed it was charging really slowly if at all, so I dropped to standard (still about 12 knots), and saw a small jump in the charge rate, then out of curiostiy I dropped it down to 2/3 (or the step below standard) and saw a bigger jump. Then it dawned on me. The devs did their homework, just like they did with SH3. With the German boats for battery charging one engine was dissconected from the prop shaft, and left connected to only the generator, leaving one prop stopped or "windmilling". This was simulated in Sh3 quite well. With SH4 the same is done with the 2 engined/ direct drive S-boat. When charging one prop is stopped. Now the newer fleet boats had four engines, none directly connected to the drive shafts, instead they were connected to a generator which in turn was connected to either the batteries, or directly to the drive motors. When traveling at slow and charging the boat would be proppelled by one or two engines, while the other two or three would charge the batteries. At standard it was two engines connected to the motors, and two to the generators. Then at full three driving one charging. At full all four would be driving, with a little bled off for charging, and at flank, no charging. In SH4 this is simulated quite well. You will also notice there is no increase in speed when the battery indicates fully charged, like you get with the older or german boats. Also, while charging both propellers are turning. I have to say, I am impressed.

07-31-07, 11:41 AM	#2
SteamWake Rear Admiral Join Date: Mar 2005 Posts: 13,224 Downloads: 5 Uploads: 0	Are you saying that the batterys recharge faster when the helm is set to 2/3 in lieu of flank ? Seems a bit counter intuitive.

07-31-07, 11:49 AM	#3
tater Navy Seal Join Date: Mar 2007 Location: New Mexico, USA Posts: 9,023 Downloads: 8 Uploads: 2	Well, when surfaced you'd expect them to run all engines. If you want the boat to move at 1/3 speed, the other engines would be charging until the batteries were topped. It's a little odd, there should be a difference between when you click the recharge batteries or not button. If set to recharge, I'd assume all engines would run, and any power produced NOT used to propel the boat at the ringed up speed would charge. When the button is off, I'd expect the boat to only run as many diesel engines as needed to produce the power needed for the ringed up speed. If you have the boat set for 5 knots, I'd expect one engine running I think. tater

07-31-07, 12:07 PM	#4
SteamWake Rear Admiral Join Date: Mar 2005 Posts: 13,224 Downloads: 5 Uploads: 0	Well in the boats where an engine is dedicated to charging duty it (that engine) would charge at whatever rate it was set for. The speed of the other engine would be irrelevant. I do know that diesel engine generators are controlled to run at a constant speed and adjust throttle according to load to maintain that speed. However that is because they have to produce a consistant 60 cycles per second regardless of load. In order to charge batteries the alternating current would have to be converted to direct current so that cycles per second would not be critical and basically the faster you can spin the generator the more 'juice' you can get out of it.

07-31-07, 12:19 PM	#5
pocatellodave Engineer Join Date: May 2005 Location: Pocatello,ID Posts: 203 Downloads: 92 Uploads: 0	I have been having a hard time with fuel conservation,but I'm doing much better now thank to a lot of help from other skippers.I use the Strict range mod,and this gives me nine knots at ahead standard,and it is the most efficient speed for mileage.I try to stay on the surface as much as possible,with battery charging off when applicable.My greatest wish would be that we skippers could determine the number of engines we wished to run on,and charge batteries.I'm pretty sure I read where skippers would run on only one engine to conserve fuel.Please someone correct me if I'm wrong.I know running with two engines for propulsion,and charging with two was S.O.P.Maybe a mod like I mentioned isn't out of the question.I thank all the people that gave me a hand with using fuel more frugally. Pocatellodave