Connecting Ground Power will not turn over engine with drained battery

Both P-51 and Spitfire dims green gear lights when starter is pushed (with or without ground power connected). In a nice touch the P-51 lights dims less if ground power is connected.

In the video I made (post #2) one can see how the (drained battery) P-51 green gear light comes back the moment ground power is connected. The (drained battery) Spitfire gear light does not come back with ground power.

In the Spitfire, the voltmeter on the panel dips when starter is pushed. What exactly does the voltmeter show? I think it shows DC battery voltage because:

a) it dips when starter is pushed

b) it shows 15V with a fresh battery and newly turned off engine

c) it dips over time down to 12V but it's still startable

d) after a deliberate battery draining it's down to around 5V

Both P-51 and Spitfire dims green gear lights when starter is pushed (with or without ground power connected). In a nice touch the P-51 lights dims less if ground power is connected.

 

In the video I made (post #2) one can see how the (drained battery) P-51 green gear light comes back the moment ground power is connected. The (drained battery) Spitfire gear light does not come back with ground power.

 

In the Spitfire, the voltmeter on the panel dips when starter is pushed. What exactly does the voltmeter show? I think it shows DC battery voltage because:

 

a) it dips when starter is pushed

b) it shows 15V with a fresh battery and newly turned off engine

c) it dips over time down to 12V but it's still startable

d) after a deliberate battery draining it's down to around 5V

Yes Voltmeter is probing voltage probably on main rail so it will show voltage on Battery, When Battery is loaded voltage drop, when starter is engaged it can drop to 10V maybe even lower.

15V on 12V battery is quiet a lot i think voltmeter isnt very precise on that matter(or this battery is just freshly charged then voltage can hit 15V level, but should decay quite quickly to 14-13V range even with circuit open).

Fully loaded 12V battery should show something around 13V.

5V at not loaded battery = battery dead, not drained just simply dead need replacement battery voltage should not drop below 11V when not loaded.

Like i said isolating battery only make no sense for me(it make sense only in one case when battery is not capable of starting engine)but in Spit or p-51 both batteries are capable of high starter amperage.

The best proof of isolated battery is to connect Ground Power and flip cockpit battery switch off, when everything still be powered so ground power is bypassing battery switch.

Ofc this is possible only in p-51 spitfire has not accessible battery switch in DCS

Looking close at voltmeter it's 14.6-14.7 just spawned and drops to 14.5V immediate after engine off (I lazily rounded up to 15 without looking closely). 14.7V fits well I think if it's a Lead-Acid battery because of

The correct setting of the charge voltage limit is critical and ranges from 2.30V to 2.45V per cell.

 

https://batteryuniversity.com/learn/article/charging_the_lead_acid_battery

I assume Spitfire has a Lead-Acid battery (invented 1859) because researching the F-86 I found it has a lead-acid and would older Spitfire have something fancier not yet invented? NiMH invented 1967.

Charging Lead Acid:

https://batteryuniversity.com/learn/article/charging_the_lead_acid_battery

(image from web site. hosted image on Imgur since "batteryuniversity" bandwidth seemed low)

Looking close at voltmeter it's 14.6-14.7 just spawned and drops to 14.5V immediate after engine off (I lazily rounded up to 15 without looking closely). 14.7V fits well I think if it's a Lead-Acid battery because of

(see diagram below)

6 x 2.45 = 14.7 V (6 cells for 12V battery)

 

I assume Spitfire has a Lead-Acid battery (invented 1859) because researching the F-86 I found it has a lead-acid and would older Spitfire have something fancier not yet invented? NiMH invented 1967.

 

Charging Lead Acid:

 

What you referring is charge voltage ok i agree but when you disconnect battery from charging voltage will drop to aproximity of 2.1V per cell in matter of 20 minutes.

So battery in spitfire is just fresh charged battery:) in DCS, Yo-Yo said something that all batteries in DCS are charged to 134% :)

What you referring is charge voltage ok i agree but when you disconnect battery from charging voltage will drop to aproximity of 2.1V per cell in matter of 20 minutes.

So battery in spitfire is just fresh charged battery:) in DCS, Yo-Yo said something that all batteries in DCS are charged to 134% :)

Agreed. Yes, it drops after a couple of minutes. I did say "immediate after engine off".

Agreed. Yes, it drops after a couple of minutes. I did say "immediate after engine off".

Ok, i missed that part :)

Some how this looks weird for me.

It indeed does. Because if it was a straight and unisolated parallel hookup, having a dead battery wouldn't mean much. The empty battery would of course act as an extra current sink, because the cart would charge it as well; but it should nonetheless have enough power for it, because the current drain caused by the battery would be negligible in comparison with what the starter requires anyway.

So it either can't be a straight parallel connection, or there's something wrong. Did you say that our Spitfire doesn't have a pilot-accessible battery switch inside the cockpit? I can't remember since I haven't flown her in ages (& am more of a Mustang and Dora man anyway).

Did you say that our Spitfire doesn't have a pilot-accessible battery switch inside the cockpit? I can't remember since I haven't flown her in ages (& am more of a Mustang and Dora man anyway).

Yes. From cockpit position you cant switch battery on/off switch is somewhere in fuselage accessible from outside or there is no switch at all, i remember that post was issued on this topic but i remember only that in side cockpit there is no battery switch.

There is small switch under throttle, which get switch on when throttle is advanced but this switch is only for cockpit lights and gages.

Yes Voltmeter is probing voltage probably on main rail so it will show voltage on Battery, ...

The pilot's notes state:

"...A voltmeter across the accumulator is fitted at the top of the instrument panel..."

So you're probably right.

A little of topic but when i compare cockpits of p-51 bf109 fw190 and spitfire.

I must say Spitfire's cockpit is complete mess for me, electric switches are all over the place, no circuit breakers, landing gear handle on the right side so pilot have to switch hands to rise landing gear, no cage on art horizon etc etc. Mess.

Did you say that our Spitfire doesn't have a pilot-accessible battery switch inside the cockpit?

There is no central battery switch, not in cockpit. Or so I've been told in these forums (it drove me crazy looking for the battery switch so I asked). Everything must be turned off one by one:

-Throttle switch (gear + fuel pressure light)

-fuel pump,

-radiator flap auto

-pitot heater

-radio

-wind screen de-icer

-navigation lights

-gunsight

forgetting something maybe

There is no central battery switch, not in cockpit. Or so I've been told in these forums (it drove me crazy looking for the battery switch so I asked). Everything must be turned off one by one:

 

-Throttle switch (gear + fuel pressure light)

-fuel pump,

-radiator flap auto

-pitot heater

-radio

-wind screen de-icer

-navigation lights

-gunsight

forgetting something maybe

wind screen de-icer where is it :P

Floor, right side.

To the point of the thread.

1) Spitfire sometimes not startable after repair is a bug. I can't see how it isn't.

2) Ground power not doing anything is also bug. I can't see how it isn't.

It looks to me like 1) is caused by a combination of drained battery and 2)

Made new track, simplest possible in a cleaned up pristine installation.

Track demonstrates that ground power doesn't turn over engine starter.

Track:

-Spawn runway (game time 10:30:00)

-shut off magnets

-run starter until battery drained (game time 10:58:07)

-Connect ground power. Note that starter doesn't turn engine over

28+ minutes total (obviously track can be fast-forwarded to say 10:58:00)

Zipped attachment

-logs folder

-Spitfire battery2.miz

-Spitfire battery2.trk

"branch": "openbeta",

"version": "2.5.6.43931",

 

Intel Core i7 3630QM @ 2.40GHz (Max Turbo Frequency 3.40 GHz)

16.0GB Dual-Channel DDR3 @ 798MHz

2047MB NVIDIA GeForce GT 635M

447GB KINGSTON SA400S37480G (SATA-2 (SSD))

a) It is annoying that the engine often can't be started after a repair (I believe it would be if ground power worked as advertised)

b) It makes no sense that ground power doesn't turn engine over (unless it does, if so, I'd like to know why)

Spitfire battery2.zip

Maybe electric starter is dead too.

Immediately after a repair? No.

Then that would be the bug, starter not being repaired when you request repair. Question is, how does it get broken?

Last night I landed a damaged Spitfire and repaired it and took off again with no problems. The only damage it had was the rudder was shot off by flack during a ground attack and the pilot required a change of pants. (New FLAK sounds are loud) So there was little chance that the starter had been hit.

Maybe we can set up an experiment shooting a Spitfire in different places and running a repair to see if it works, maybe the stater is the Spitfires prop governor.

Then that would be the bug, starter not being repaired when you request repair. Question is, how does it get broken?

 

Last night I landed a damaged Spitfire and repaired it and took off again with no problems. The only damage it had was the rudder was shot off by flack during a ground attack and the pilot required a change of pants. (New FLAK sounds are loud) So there was little chance that the starter had been hit.

 

Maybe we can set up an experiment shooting a Spitfire in different places and running a repair to see if it works, maybe the stater is the Spitfires prop governor.

My question is why battery isn't replaced after repairing plane ?, If ground crew is capable of repairing almost all damage why they did not replace battery, that is so so stupid :P

If they cant replace battery , so they are capable of not repairing starter too

Immediately after a repair? No.

Why are you so sure about that ?

Because ground power not powering starter is a bug. Would there be two bugs? Less likely.

I'm fishing for BIGNEWY input. I made the case as simple as I could, a page back.

Because ground power not powering starter is a bug. Would there be two bugs? Less likely.

 

I'm fishing for BIGNEWY input. I made the case as simple as I could, a page back.

Why are you so sure that starter is repaired ? When battery is not.

Repair should fix everything, should refill coolant oil oxygen, battery, fix broken stuff.

Why are you so sure that starter is repaired ? When battery is not.

a) Again, because the known bug (ground power) already explains the behavior.

b) And ... it makes no sense "repairing" each part separately. They'll just spawn a new aircraft (keeping fuel levels *1).

Did an experiment, the P-51 does not recharge/replace battery on repair.

-I damaged the P-51 a little (swinging ass into a jeep)

-shut off engine and drained it's battery

-repaired

-P-51 battery was dead before repair and remained dead after repair (but startable with ground power)

Assuming the Spitfire works the same, does not recharge/replace battery over repair, a drained battery would make it unstartable (and ground power is bugged).

*1) "Interesting" difference between Spitfire and P-51 repair. The P-51 returns to ambient oil and coolant temps after repair. The Spitfire retains oil and coolant temps over repair.

This thread is 10 times longer than it needs to be. But I'm sure BIGNEWY loves sifting through long threads in bug reporting:cry: Again, reference to my post where I presented the ground power bug as simple as I could.

I will add that oxygen tank is not replaced or refueled in repairs nor in refueling which should be addressed by one of this procedures i think.