Hello,
just wanted to add to sth. i said before:

Normal charge (quick charge did not really change the recharging times):
(previous de-charging/emptying with 2750 A = 8250 Ah)

Full charge:
9488 Ah = 115 % 6 hours 45 minutes
9075 Ah = 110 % 6 hours
8890 Ah = 100,5 % 4 hours 30 minutes
new -- > 7310 Ah = 88,6 % 3 hours 45 minutes

I took the numbers out of graphs describing grades of effectiveness and battery-graphs. The times may differ depending of all those other influences mentioned before and losses during transfer, mechanical and electrical. However the numbers above are what was observed and tested in reality, so no theoretical calculations.

Tested battery type: 44 MAL 740 E/21, 6 x 62 cells

From what i understand the batteries had been emptied with 8250 Ah here, a full new charge (115%) would be 9488 Ah (this is Ampère per hour, so it was discharged with one A for 8250 hours, or 8250 A in one hour, or most probably something in between). Don't know whether this is correct, but if i substract one number from the other, the emptied battery would still have had some 1238 Ah - maybe this is not a "deep discharge", but a level that would be usual during a normal cruise without draining the very rest out of the batteries and probably damaging them.

I'm still looking through the book, but please bear with me, the information is scattered over all those pages ;) - i'll post again if i find something new.

Thanks and greetings,
Catfish

Excellent job, Catfish. I just finished my tests so we can start comparing the SH3 XXI with the real life XXI.

On your battery discharge information, does that mean the battery still had about a 14 percent charge? I must admit, it has been some time since I studied electronics. :oops: If that is what it means then the XXI charged even faster then I thought.

The information from my tests is in a series of tables that I can't really post here on this forum without a lot of effort. I am going to host it on one of my webservers and post a link to it. - Edit - Hmm, my free web hosts seem to have forgotten who I am. :shifty: I will have to find another way to do this.


Ariel (AKA User 1834 :-? )

Send the tables over to me (contact me through PM if you need an email addy), I'll host them

Hello,
just found full capacity of batteries is 11300 Ah, full battery weight 240 tons.
So the test was done with batteries fully charged, then 3-hour discharge with 2750 A, so 3x 2750 = 8250 Ah. We have to substract 8250 from 11300, which is 3050 Ah left in the battery, this is a bit less than one third overall capacity left.
Greetings,
Catfish

Here are the tables:

http://server4.realsimulation.com/Ba...nformation.htm

Thanks, Terrapin and Catfish.

Okay, I think then that we can confirm with all of this information that the XXI in SH3 does not charge at a historically correct rate. Now we just have to figure out how to fix it. Ideas anyone?

Update - I have tried several fixes suggested by SeaSlug but they have not had any effect. I am going to continue trying different combinations of diesel engine power and electric motor power.

Syxx_Killer,

Thanks for mentioning problems with IXD2 'radar/sonar destroyed'. I thought this problem occured only with XXI and VII-C/42 subs.

I have not used the IXD2 much, and never saw an (F3-screen) scrolling radar/sonar-destroyed 'text' message, but the (F7) sub display radar-compartment will show a 'Sonar Destroyed' in red. I'm not sure sonar is really destroyed but it says it is :)

I don't think the IXD2 had self-destructing radar. I know my choice of wording may have eluded to it, but I'm just not sure. :-? I'm using the IXD2 in a career, but have only got the sonar destroyed message (S-Gerat).

I'm not sure what the F3, or F7 screen is. I never use the F keys to switch stations. :oops: The text message appears immediately upon start of a career mission (not sure about single missions as I hardly every play them). The sonar in the game is really active sonar. Getting the sonar destroyed message, and consequently, the destroyed sonar only affects you ability to ping a contact. You can still use your hydrophones. I guess this self-destructing sonar bug really doesn't bother me because I very rarely, if ever, use the sonar. Now, if it were the hydrophones that were bugged, then that would be disastrous and downright mean! :88)

Ariel, I'm sorry it didn't work (E_prop adjustment).

Now here's the logic behind it. Type IX for example, has an E_Prop of about 1000, whereas the diesel puts up 4000. The XXI has a diesel of 5500 and E_prop of 4400 (or something like this).

Anyway, as some people in the thread you posted me said, the more efficient E_prop is (lower HP that is), the slower it will recharge. Could make sense.

I did increase the diesel to 10.000 and the batt recharged significantly faster. However, it'd burnt the fuel like hell. So it is a no win - no win situation.

As to the FUMO 391, it seems no one found a way to fix it. Damn, in 44, it is the only way to use the radar (atop the snorkel), otherwise a bunch of Lancs or Catalinas are gona send ya right to the bottom. Besides, it is the only way to see them in time to dive and run like hell.

Hmm. Perhaps there is some way to compensate for the increased diesel usage? I am going to try the 10,000 diesel power setting and see how long it takes to recharge. If it does work then there must be a way to compensate for the increased speed and diesel usage.

Ok, I'll say it again. Fiddle with -" SHP PLUS RPM "

E Propultion = DRAIN

D Propultion = CHARGE

Battery Multiplyer = RATE

Ok example - increase SHP, decrease RPM = Same consumption same speed, but different Drain/Charge properties or increase RPM, decrease SHP.
However, be aware that a FASTER D Propultion RPM with more SHP than an E Propultion RPM and SHP resualts in a faster speed at snorkel depth.

The Type XXI is REVERSE to all other Subs in that it has a Better E Propultion than its D Propultion.

Ohh PS : The Type XXI does NOT have a RADAR mounted ontop of its Snorkel, its ment to be the Radar Warning Reciever IIRC. A radar ontop of the snorkel at sea level is rather redundent as it would have a VERY limited range, BUT a reciver to pickup the aircraft radar is of course self explanertory !
However placing a Radar emmiter ontop would be nice for when ur surfaced to get a tad more range :)

OK, thanks, I thought the RPM are purely decorative.

PS: Apropos de Radar. :roll: The SH3 files say the FUMO 391 RADAR was put on top of the snorkel. Hystorical accuracy? Dunno?!!

Anyway, since these people figured out jet engines, rockets, and other nice gadgets, I find it hard to believe they never figured out how to put an extensible antena on the sail?! :rotfl: You may snorkel, but while you snorkel you're a sitting duck (whale) :hmm: Hard to believe...

So whatever goes on top of the snorkel, I'm happy with, as long as it gives me a bit of warning!!!!!!!! :stare:

I never heard of them putting, or planning to put, a radar on the snorkel. What they DID place on the snorkel however was the Naxos radar detector.
http://uboat.net/types/illustrations/schnflv.gif
"The Floating valve type (top) is seen here with the rare but sophisticated Naxos radar detector mast."

Actually they had 2 extra, 1 for the Radio Mast and 1 for the Radar MAST.

Now heres the kicker, in SHIII BOTH masts are modeled, but u just cant RAISE them !

I have seen INSIDE the Sail, and yes BOTH masts are there !!!