POSSIBLE ANSWER---> Fuel Cells: Inputs and Outputs????

[Wallygator]

UPDATE: I think I found the answer (see Post No. 14 please)

Specifically, can you restrict the tanks they draw fuel from AND still allow full recharging of all vessel electrics?

Any experiences? Thoughts? Best practices?

It could be completely obvious - So I might have a bit of a mental block ;-)

Many thanks in advance!

W.

Edited July 12, 2015 by Wallygator

[Xannari Ferrows]

Good question. I'm not sure if they follow the rules of the valve closer [the little green arrow]. It has this line:

FlowMode = STAGE_PRIORITY_FLOW

So I'm assuming if you block off the tank with the valve then it'll stop draining fuel from there, but I've never tested it. I only use cells for rovers and bases.

[Red Iron Crown]

You can disable tanks so that the cells don't draw fuel from them.

Edit for Ninja Ferrows: STAGE_PRIORITY_FLOW is like monoprop, it will draw from all tanks evenly in a stage, with stage determined by number of decouplers between tank and root part.

[Wallygator]

You can disable tanks so that the cells don't draw fuel from them.

Hmmm... But since I can't shut off a tank via an action group that would mean I need to right click on EVERY tank in my vessel to set its fuel access.

I don't like that option.

Perhaps there is an action group mod that can handle that? need to check...

- - - Updated - - -

The Fuel cells clearly draw fuel from the farthest tanks in the fuel flow chain (from what I can see).

It would be nice to be able to specifically designate any fuel tank as "FUEL CELL ASSIGNED" and these tanks would be the only ones that any fuel cells would draw from.

Here is my current predicament...

Inside the CSM service bay we have two groupings of oscar tanks each with a small fuel cell - these two units represent a couple of fuel cells. Ideally a fuel cell would ONLY draw fuel from three oscar fuel tanks aligned to it. Once the tanks are empty, the fuel cell is spent.

Make sense?

Would a part without crossfeed work to isolate the subassembly? or would that also prohibit electric charge pass through?

Edited July 11, 2015 by Wallygator

[Sharpy]

Don't decouplers prevent crossfeed to the likes of these?

[Wallygator]

I guess I need to now conduct a test.

EDIT: Test conducted, I placed a small decoupler between the three oscar tanks and the cubic strut. No effect. The fuel draw continues to pull from the farthest tanks in the fuel flow/staging sequence.

Edited July 11, 2015 by Wallygator

[Xannari Ferrows]

Try removing the FlowMode line, and see if that works.

EDIT: You might need fuel lines, but I'm not sure about that.

Edited July 11, 2015 by Xannari Ferrows

[DancesWithSquirrels]

What happens if you disable crossfeed in the docking coupler ?

[Xannari Ferrows]

What happens if you disable crossfeed in the docking coupler ?

That only works with STACK_PRIORITY_SEARCH I believe. It may work with ALL_VESSEL as well.

EDIT: Wait a minute... That just might work. If you change the FlowMode to STACK_PRIORITY_SEARCH, it will [or at least should] drain fuel the same way an engine does. [Engines follow part crossfeed rules, while Jet Engines and Fuel Cells don't]

Then again, I'm starting to think this may be related to the ModuleResourceConverter.

Edited July 11, 2015 by Xannari Ferrows

[Wallygator]

Try removing the FlowMode line, and see if that works.

EDIT: You might need fuel lines, but I'm not sure about that.

Doesn't work. commented out the lines for both oxy and liquid tried with and without fuel lines - still draws resources from all tanks. Grrrr...

That grr is for the module, not for your assistance ;-)

Are there any other values for FlowMode?

EDIT: just saw your edit. give me a bit of time. I'll test again...

EDIT2: And.... no. still draws from all over. Reinstating the "Grrr" :-)

Edited July 11, 2015 by Wallygator

[Xannari Ferrows]

Really? Okay, I'm convinced this is a module issue at this point.

[Wallygator]

It's likely not a "bug" persay, but it really doesn't operate like a real fuel cell which is a unitized self contained source of electric and water.

Everyone who contributed gets a big thank you and rep if I can give it. (Sorry red, my rep to you is blocked so please accept sunshine, wine, cheese and positive rays...)

Edited July 11, 2015 by Wallygator

[Wallygator]

OK, I had one last try with what SHOULD work (in my perhaps naive view), I isolated a stack of three oscars and a fuel cell from the rest of the vehicle via a Clamp jr. docking port and then turned off the cross-feed.

And...

Still Failure :-(

Nothing I can do in the stock game allows me to isolate tanks attached to a fuel cell from the rest of the vehicle. I can't create a standalone fuel cell which is disengaged from the wider ships propellent systems.

I find is beyond the realm of understanding that a crew would have to turn off ALL the propellent systems in their vessel just to properly isolate a fuel cell power generator and let it operate properly.

Funny. Not a deal breaker but definitely a head scratching moment.

[Wallygator]

EUREKA!

Ok, found it.

There is a value for flowmode = STACK_PRIORITY_SEARCH. This seems to restrict flow to/from a resource in the moduleresourceconverter. In the instance of my ideal fuel cell, when flowmode is set to "STACK_PRIORITY_SEARCH" for an input resource (LF and OX in this instance), then any resource connected to the fuel cell is consumed and it is NOT replenished from the vessel's resource stack that lies outside the bounds of a crossfeed disabled part.

So after Frankensteining the part configs from the OscarB and small fuellcell I was able to muck around with flowmode to construct a test mule part which performs as I intend.

EDIT: What actually happens is that the part will draw resources from an adjacent resource BUT a crossfeed part (Clamp jr. or decoupler) can now be placed between the fuel cell and the rest of the vessel and prevent resource flow in. You can still allow the fuel cell to pull vessel resources by enabling cross-feed on the docking port. I might be able to just hack the fullcell config and not have to make a part model. Joy.

Am I correct here?

Now on to learn Blender. lol.

Edited July 12, 2015 by Wallygator

[Foxster]

I think this is the same issue as with RCS. There has never been an easy fix for that either. Closest is to use the TAC Fuel Balance mod, which might give you the fix you need.

[Wallygator]

I think this is the same issue as with RCS. There has never been an easy fix for that either. Closest is to use the TAC Fuel Balance mod, which might give you the fix you need.

Thanks, yes I recall the RSC issue now that you mention it. I would really like a functional analogue fuel cell. I think that having created a workable standalone part config, then the best action now is to take it for a spin. I will need a new part mesh at some point, but repurposing the OscarB tank .mu is sufficient for these purposes.

[SAI Peregrinus]

Thanks, yes I recall the RSC issue now that you mention it. I would really like a functional analogue fuel cell. I think that having created a workable standalone part config, then the best action now is to take it for a spin. I will need a new part mesh at some point, but repurposing the OscarB tank .mu is sufficient for these purposes.

The alkaline fuel cell from Universal Storage might also fit your needs. It uses Hydrogen/Oxygen instead of LF/O, and comes with a bit of internal fuel. There are also tanks for it.

[Wallygator]

The alkaline fuel cell from Universal Storage might also fit your needs. It uses Hydrogen/Oxygen instead of LF/O, and comes with a bit of internal fuel. There are also tanks for it.

Fair enough, I will check it out.

However, with this small config file change (I like to think it is a correction) in the two stock fuel cell parts, I can now create an isolated fuel cell from stock tanks. It still allows them to operate normally as I think the devs intended, but they now behave properly when a docking port is present and crossfeed is disabled.