battery recharge

[edwardallen]

how long should it take to rechargethe batteries from say 50% to 100%
at 12knots

[raymond6751]

You can do your own tests en route to missions. Too many variables.

[joefremont]

It might be more reliable to test from 10% to 100% as the sim will drop you out of time compression when you hit 10%. Like raymond said test it while enroute to your mission. Dive to periscope depth and ahead 2/3 until you reach 10% battery. Surface, ahead 2/3 and note the time when in the log when you start and when you reach 100%.

[Stealhead]

First stock or modded as mods effect battery recharge Trigger Maru Overhauled in particular.Second what sub are you in has an effect.
Third effect is speed the higher the speed the faster the recharge rate.Inversely recharging batteries consumes more fuel than normal cruising.

It is a simple matter really simply observe how long it takes to recharge one unit of battery juice then take that data and do the math to discover how long it will take given how many units of juice you need to fill.

I play TMO 2.5 and I think it takes about 15 minutes to fill one unit of juice at ahead standard in any of the fleet boats.That is around 4 units per hour.It might be slightly longer I usually only run my battery down to 75~80% at most and that only takes around 3 hours to recharge.Honestly I have played so much that detail has become instinct I will know it based on the current situation(boat,juice needed,speed of the boat).

Basic rule of thumb at least with TMO is that it takes 1 hour to charge two units of juice.

I try not to run down my battery too much by only diving when I need to and then only going ahead slow in order to consume the least amount of juice.

As the others said you'll have to experiment and discover how long it takes to fill one unit then do the math from there.

[TorpX]

how long should it take to rechargethe batteries from say 50% to 100%
at 12knots
In RFB, with the S-class, it takes a long time. I try very hard not to run it down too far, in such circumstances.

[oldretseal5326]

I have found that all the subs except for the S models will recharge the batteries at about 8% per hour at standard speed. The S boats both take forever to recharge. I suspect that is probably accurate with the real subs due to the time they were in service. Technoligy obviously improved from the early forties to the mid forties. Hope this helps.
Oldretseal

[Redmane]

The older boats, pre-Sargo class boats, used commercially produced batteries, which were not able to perform like the later specially designed batteries, which were first installed in the Sargo class boats, hence the name: "Sargo Batteries." Also the speed you run while recharging will also change the recharge rate. The fastest way is to simply call "All-stop" and sit until you are fully recharged (this works in TMO, not sure about the stock game), as then all diesels will be powering the charge. The faster you run, the more diesels you need to maintain your speed, so you may have only one to charge the batteries. Having read actual patrol reports I found it interesting to note that often times the commanders would refer to the speeds they traveled as "two-engine" or "three-engine." etc.

[Stealhead]

The fastest way is to simply call "All-stop" and sit until you are fully recharged (this works in TMO, not sure about the stock game), as then all diesels will be powering the charge


That is a cheat really though with no engines running in a real WWII US Navy sub you would also not be turning the generator which charges the batteries.That is something the game itself allows that is in fact not realistic.I say this because in SH4 and especially in TMO and RFB while at all stop you can plainly see by looking at the tachometers on the bridge (swab the deck if have no idea where the tachs are) and by hearing the the diesels are not running.


In theory you could use all 4 engines but out at sea and especially in a war zone where an enemy could appear at any moment(including an enemy submarine submerged) sitting dead still in the water is a spider monkey about to poke you with a death stick vigorously.

You would always have at least one engine running for propulsion and one for charge.If you wanted more speed youd have two on propulsion and one on charge and for maximum speed while still needing to charge batteries you would have 3 on propulsion and one on charge.

That is where the the traveled on "two engine" or "three engine" comes from though in that case unless they specifically mention that batteries need charging is describing how many engines are being used for propulsion.

It really worked like this:

http://www.hnsa.org/doc/fleetsub/elect/chap2.htm#2A

[Red October1984]

I use tactics that I've picked up in Documentaries and in books. I'm by no means an expert but I have found what seems to work.

For batteries, sometimes I run at ahead slow during the daylight hours and charge batteries at night. That's when I'm in no hurry. It's also a very useful tactic when aircraft are around. Pop your Radar antenna up every once in a while and keep tabs on the patrols. I'll run on the surface 24 hours if I have to be somewhere for an intercept or other mission assignment.

[TorpX]

I have found that all the subs except for the S models will recharge the batteries at about 8% per hour at standard speed. The S boats both take forever to recharge. I suspect that is probably accurate with the real subs due to the time they were in service. Technoligy obviously improved from the early forties to the mid forties. Hope this helps.

This is not accurate, but unfortunately, there doesn't seem to be a good way to fix it. Certainly, the older boats had older design batteries, but smaller, older batteries do not necessarily take longer to charge. Most likely, they just had less capacity.

This thread had a good discussion on S-boat batteries:
http://www.subsim.com/radioroom/showthread.php?t=200773&highlight=battery&page=4



That is a cheat really though with no engines running in a real WWII US Navy sub you would also not be turning the generator which charges the batteries.That is something the game itself allows that is in fact not realistic.I say this because in SH4 and especially in TMO and RFB while at all stop you can plainly see by looking at the tachometers on the bridge (swab the deck if have no idea where the tachs are) and by hearing the the diesels are not running.

I don't recall it working that way in RFB. I think, you could sit still and have your desiels running to recharge (in a S-boat). I don't know if this really made it faster or not.

[BrucePartington]

This is modelled since SH (or SH1 if you like). And I just confirmed it 2 days ago, after downloading and installing DOSbox :sunny: :D
In SH, in the gauge panel there is an engine service/function indicator on the top left. 2 engines are modelled, and for each, 2 lights are present: GREEN means propulsion, RED means charging. When I call "All stop" both engines are set to charging (if needed of course). And it makes sense, since you want to have your batteries fully charged, and you never know when an enemy encounter will pop up.
I wouldn't think it's cheating, it's common sense and it's feasible.


Now a video game may or may not give you the option to control this function, but I have reason to believe in real life you would be able to set all your engines to charge (if needed), if you were stopping the boat surfaced, while the crew conducted the night chores.

Converselly you could decide you needed all engines online for propulsion for max surface speed, it being a temporary priority over recharging batteries. I've done that in SH3. Never did it in SH4, and have no clue if it's possible, never looked for it.

That is a cheat really though with no engines running in a real WWII US Navy sub you would also not be turning the generator which charges the batteries.That is something the game itself allows that is in fact not realistic.I say this because in SH4 and especially in TMO and RFB while at all stop you can plainly see by looking at the tachometers on the bridge (swab the deck if have no idea where the tachs are) and by hearing the the diesels are not running.


In theory you could use all 4 engines but out at sea and especially in a war zone where an enemy could appear at any moment(including an enemy submarine submerged) sitting dead still in the water is a spider monkey about to poke you with a death stick vigorously.

You would always have at least one engine running for propulsion and one for charge.If you wanted more speed youd have two on propulsion and one on charge and for maximum speed while still needing to charge batteries you would have 3 on propulsion and one on charge.

That is where the the traveled on "two engine" or "three engine" comes from though in that case unless they specifically mention that batteries need charging is describing how many engines are being used for propulsion.

It really worked like this:

http://www.hnsa.org/doc/fleetsub/elect/chap2.htm#2A

[Stealhead]

Now a video game may or may not give you the option to control this function, but I have reason to believe in real life you would be able to set all your engines to charge (if needed), if you were stopping the boat surfaced, while the crew conducted the night chores.



As I said in my original post you could choose to sit still in the water and have all charging however in a war zone this would be a very dangerous tactic that would place the boat at risk.You simply do not want to be a sitting target if you do not need to be.In real WWII there was always the chance that an enemy vessel or aircraft might find you and if your siting dead still you have made yourself an easy target.I have never read of any WWII submarine commander in any navy consider sitting dead in the water to be a sound idea.Even during a night surface they would creep along and run on the battery.

I am not sure with U-boats but all fleet boat also had a smaller "pony engine" that could be used exclusively to charge the batteries and allow the main engines to focus on propulsion.I believe that Type VII and XI boats also had a "pony" engine as well.On fleet boats if the need for charging the batteries was not deemed to be imminent or only a small amount of charging was needed they usually would have the pony engine charge the batteries.

At any rate there would be no reason to place all engines on charge anyway when considering that most every submarine had a fairly effective way to charge the batteries at a reasonable rate while still also maintaining normal propulsion.

The pony engines are not simulated in the SH series combining that with how the game simulates charging this is an element of real life submarine activity that you have to "pretend" that your doing the way a crew really would have performed that task.

My distaste for sitting still at sea comes from reading many books by submarine crews and knowing the fact that even though the game does not simulate the threat of an enemy sub it was a very real threat as was the general danger that having no momentum from propulsion would greatly increase the time it takes for the sub to make an escape if a threat should appear.Additionally with in the bounds of the game if you sit idle and charge the batteries it does not consume fuel which to me is an exploitation.

[ETR3(SS)]

US Fleet boats were always propelled by the electric motors, hence the diesels onboard were diesel generators. They would run to supply the boat with its electrical needs on the surface. In a safe spot and need to recharge your batteries? You could order all stop and run a charge using all 4 diesels. Just sayin.

[Stealhead]

I use tactics that I've picked up in Documentaries and in books. I'm by no means an expert but I have found what seems to work.

For batteries, sometimes I run at ahead slow during the daylight hours and charge batteries at night. That's when I'm in no hurry. It's also a very useful tactic when aircraft are around. Pop your Radar antenna up every once in a while and keep tabs on the patrols. I'll run on the surface 24 hours if I have to be somewhere for an intercept or other mission assignment.


You must not have read "Thunder Below" because Fluckey only submerged when he needed to other wise the Barb was on the surface.Some like to call it "Yo-yo" the yo-yo stays up in the hand (on the surface) when a threat is detected the yo-yo goes down (submerged) when the treat passes the yo-yo goes back up.Fluckey and several other skippers most all of the top scoring skippers in fact(Fluckey,OKane,Morton) preferred to stay on the surface to maximize search area.Additionally batteries are conserved using the "Yo-yo" tactic which means that when yo do need to stay submerged for an extended time you will have a full set of batteries.

A patrol plane typically takes about 1 to 2 hours to come back on its return leg which is usually within about 15 miles of the point he flew over the first time.Using Yo-yo you submerge when see that an aircraft will pass close enough to see the sub the you stay down long enough for him to pass and come back patrol on the surface again if he comes back an hours later Yo-yo once again.

Ask Rockin Robbins or Armistead about Yo-yo they will tell you.I read some of their thoughts on this method and was not a believer.Then I read "Thunder Below" and Fulckey convinced me that this was a very sound and effect tactic(he describes a great detail better than I can why Yo-yo is the best most effective way to use a fleet boat.Don't be an Ostrich.

[Stealhead]

US Fleet boats were always propelled by the electric motors, hence the diesels onboard were diesel generators. They would run to supply the boat with its electrical needs on the surface. In a safe spot and need to recharge your batteries? You could order all stop and run a charge using all 4 diesels. Just sayin.

The entire point is in a war zone there is no "safe spot".Again I never said that you could not do this I said that it is a very unsound tactic to sit still in enemy waters saying "here I am sitting here dilly dallying please shoot me IJN sub I am a big fat sitting duck."


I originally posted:

"In theory you could use all 4 engines but out at sea and especially in a war zone where an enemy could appear at any moment(including an enemy submarine submerged) sitting dead still in the water is a spider monkey about to poke you with a death stick vigorously."

In other words yes by design you could have all main engines on charge but in practice there is no reason to do it.

[Red October1984]

You must not have read "Thunder Below" because Fluckey only submerged when he needed to other wise the Barb was on the surface.Some like to call it "Yo-yo" the yo-yo stays up in the hand (on the surface) when a threat is detected the yo-yo goes down (submerged) when the treat passes the yo-yo goes back up.Fluckey and several other skippers most all of the top scoring skippers in fact(Fluckey,OKane,Morton) preferred to stay on the surface to maximize search area.Additionally batteries are conserved using the "Yo-yo" tactic which means that when yo do need to stay submerged for an extended time you will have a full set of batteries.

A patrol plane typically takes about 1 to 2 hours to come back on its return leg which is usually within about 15 miles of the point he flew over the first time.Using Yo-yo you submerge when see that an aircraft will pass close enough to see the sub the you stay down long enough for him to pass and come back patrol on the surface again if he comes back an hours later Yo-yo once again.

Ask Rockin Robbins or Armistead about Yo-yo they will tell you.I read some of their thoughts on this method and was not a believer.Then I read "Thunder Below" and Fulckey convinced me that this was a very sound and effect tactic(he describes a great detail better than I can why Yo-yo is the best most effective way to use a fleet boat.Don't be an Ostrich.


This is why I said sometimes. I don't always run submerged during daylight...but it can be useful.

It was in War in the Boats.

[Stealhead]

This is why I said sometimes. I don't always run submerged during daylight...but it can be useful.

It was in War in the Boats.


Your last sentence(in post #9) implied that being on the surface most of the time was the exception not the rule.

Sorry I am a firm believer in Fluckeys Yo-yo.Yo-yo and Ostrich are his terms not mine.

[TorpX]

As I said in my original post you could choose to sit still in the water and have all charging however in a war zone this would be a very dangerous tactic that would place the boat at risk.You simply do not want to be a sitting target if you do not need to be.In real WWII there was always the chance that an enemy vessel or aircraft might find you and if your siting dead still you have made yourself an easy target.I have never read of any WWII submarine commander in any navy consider sitting dead in the water to be a sound idea.Even during a night surface they would creep along and run on the battery.


Just because Fluckey didn't do it, doesn't mean it wasn't done. O'Kane did it. The purpose wasn't so much to speed up charging as it was to save fuel. They were on the surface day and night scanning the horizon for contacts, and listening with the hydrophones. Nobody could sneek up on them. Then, at night, they would move 20 miles to a new spot, and spend a day there. In this way, he greatly stretched his fuel supply.