New Battery time

[EricJ]

5 hours ago, FlyingDude said:

Microcontrollers and Fpgas run at 3.3V and 0.9V core voltages but that doesn't mean the unit will run at lower than rated voltages. 

Yes, circuit device voltages can be pretty low, I was talking about the power supply output voltages that go to the typical boards.   Often that's 5V, sometimes lower if nothing on the board needs higher.   If the power supply can still regulate, the boards will run and the lower required the better with a fading battery.   Some boxes (like my IFD) will log internal voltage status and many of them are pretty low.   Many boxes these days have the same power supply for either 24V or 12V input and just regulate internally regardless of the input.   They'll go pretty low, and as long as they can support the highest required internal voltage, it'll keep running.    My recollection of the last time I looked at something like this the highest internal voltage requirement was for the Tx power amp.   So the first thing you'll likely lose with a fading battery for such a system will be transmit power.   The rest of it may run significantly longer.    Naturally it'll be device dependent, but that seems to be how a lot of things are architected these days.

[FlyingDude]

@EricJ so ... Did you check which ones of your avionics survive at <12V? 

[EricJ]

12 minutes ago, FlyingDude said:

@EricJ so ... Did you check which ones of your avionics survive at <12V? 

I don't think it matters what mine do.  People who are worried about it can check their own equipment, since they're likely to differ depend on the engineering tradeoffs chosen for each.  Some manuals include such info, e.g., my IFD Pilot's Guide says it'll give a 60-second shutdown warning at 9V and internally power down between 6-8V.    That sounds about right to be able to reliably regulate 5V on the load side of the power supply.

[Brian E.]

I know of several short body airframes with their battery up front that would benefit from the CG shift to the rear.  I'd love to give it a go aside from the $700 price tag. Incidentally, when my sealed Concorde failed I went with a sealed Gill and couldn't be happier.  I certainly wouldn't be afraid to try an Earthx if the price we're a bit more competitive.

[Ragsf15e]

42 minutes ago, EricJ said:

I don't think it matters what mine do.  People who are worried about it can check their own equipment, since they're likely to differ depend on the engineering tradeoffs chosen for each.  Some manuals include such info, e.g., my IFD Pilot's Guide says it'll give a 60-second shutdown warning at 9V and internally power down between 6-8V.    That sounds about right to be able to reliably regulate 5V on the load side of the power supply.

I think @Yettishould crank up all his avionics with the old battery and see how long it lasts.  When things start dropping offline, he can shutdown, pop in his new battery and be on his way.  We’d all learn from it!

[philiplane]

5 hours ago, rickseeman said:

I already have A/C and I'm W&B challenged. I need a MT but I guess I'm a CB. There's nothing really wrong with my CG. I can have only 2 people up front and no problem but people say they handle and land better with an aft CG. (I'm probably using CG as an excuse for wanting a MT because I think they're sexy.)

MT's sure look good the moment they're bolted on, but the love affair is short. You'll get tired of cleaning grease from your windshield, and paying your mechanic to constantly replace lost filler around the leading edges, sanding and painting the blades, and resealing a few times before it reaches TBO. 

If you want sexy without the hassles, you want a Hartzell composite prop. They are a work of art, and highly durable. 

[A64Pilot]

While I too marvel at the Hartzell composite, it is after all a “true” composite not a fiberglassed wood prop.

Best be sitting down when you find out what it costs.

[rickseeman]

To philiplane: I really wouldn't be able to handle that at all.

[FlyingDude]

2 hours ago, EricJ said:

info, e.g., my IFD Pilot's Guide says it'll give a 60-second shutdown warning at 9V and internally power down between 6-8V.

Does it have its own battery,  the way G5s do? 

[EricJ]

Just now, FlyingDude said:

Does it have its own battery,  the way G5s do? 

No, it runs solely off the avionics bus.

[Fly Boomer]

14 hours ago, Brian E. said:

I know of several short body airframes with their battery up front that would benefit from the CG shift to the rear.  I'd love to give it a go aside from the $700 price tag. Incidentally, when my sealed Concorde failed I went with a sealed Gill and couldn't be happier.  I certainly wouldn't be afraid to try an Earthx if the price we're a bit more competitive.

How many hours has the Gill lasted so far?

[Pinecone]

13 hours ago, philiplane said:

MT's sure look good the moment they're bolted on, but the love affair is short. You'll get tired of cleaning grease from your windshield, and paying your mechanic to constantly replace lost filler around the leading edges, sanding and painting the blades, and resealing a few times before it reaches TBO. 

If you want sexy without the hassles, you want a Hartzell composite prop. They are a work of art, and highly durable. 

If or when it becomes available for Mooneys.  I talked to Hartzell about this at Mooney Max.  Right now, it is vaporware

 

[Brian E.]

10 hours ago, Fly Boomer said:

How many hours has the Gill lasted so far?

Quick math says about 500 hrs and over 3 years.

Edited July 18, 2023 by Brian E.

[philiplane]

On 7/17/2023 at 10:27 AM, Pinecone said:

If or when it becomes available for Mooneys.  I talked to Hartzell about this at Mooney Max.  Right now, it is vaporware

 

The M20R & S composite Hartzell prop has been available for 8 years now.

Edited July 19, 2023 by philiplane

[Pinecone]

Hmm, they did not mention that.  But I need one for a K.

[philiplane]

1 hour ago, Evan said:

Most of this is no longer true. I have an MT on my J and they fixed the issue with the grease leaking from the hub. Your statement was accurate 5-10 years ago. 

The grease leaks on some have slowed, if they have the later style seals after 2019 or so. They last a bit longer before leaking again. 

I've got two MT's, one new in 2016, and one new in 2018, that have been repeatedly re-sealed, with the revised seals. They still leak. Many prop shops won't work on them since they don't want the hassle of continuous leaks. Filler still chips off, the paint wears prematurely. Want to see how sorry a 2023 MT prop on a DA40 with less than 300 hours looks like? I'll get some fresh photos. You're lucky yours doesn't leak, but if you start putting over 300 hours a year on it, it will. 

 

[201Mooniac]

5 hours ago, Evan said:

Most of this is no longer true. I have an MT on my J and they fixed the issue with the grease leaking from the hub. Your statement was accurate 5-10 years ago. 

I've had my MT prop on my M20J for 4 years now and not a single issue.  No grease leaking, no problems with the paint, everything has been great.

[philiplane]

Fresh grease leakage today, YAY MT! All three blades. Good thing is that there is no way to lubricate the hub, so it'll stop leaking when it's empty...

Edited July 21, 2023 by philiplane

[MB65E]

The new -25 blades for the Extra are awesome! Agreed on every thing else about MT! Would love to have the new Trailblazer Hartzell composite for the Mooney one day. 

-Matt

[A64Pilot]

Interesting thing about @philiplane is he lives within spitting distance of MT which is in Deland Fl.

Surely if his issues were correctable they would have been done so by now.

[cliffy]

Back to batteries-

Just a couple of thoughts-

For those who brag about how many years they get out of a battery-

What do you think the "capacity" of your battery was on the last flight you flew before it wouldn't start your engine? 

Was that a  full IFR flight in Wx?  What if your alternator died on that flight? How long would your electrical system have run then? 

Would you have time to get on the ground before the panel went red X or your radios died?

Starting the engine is a secondary purpose for the battery, keeping your panel alive with an alternator failure is the primary use.

This is why a capacity check is called for on ICAs for batteries YET almost no one (even those who think nothing of flying in heavy IFR in single engine airplanes) 

even considers it at annual time. 

Second thought-

Unless I'm wrong (could be but) 

33 amp hours vs 11 amp hrs of power delivery ? Amp hrs of delivery is still amp hours. 11 is 1/3 of 33. 

How long will 11 amp hours run YOUR panel? Do you even know what your electrical system uses when running?

You should have in your A/C records a generator load sheet and the total load of "usually" on items shouldn't exceed

80% of you generator capacity. Take a look and see what YOUR system actually uses in flight. Then determine how long your 

panel will work with a PERFECT battery. It might surprise you. 

In old 737s we had "maybe" 30 mins if we went down to DC only, A true emergency as from cruise to landing it might be much

longer that 30 mins to get down and on the ground. 

How long would it take you to get on the ground in IFR conditions IF your generator quit? Would your battery last long enough?

Everyone's airplane will be different. 

Delivery time is what we need in flight. If only starting power was the consideration then 11 vs 33 wouldn't make any difference.

We have no mandated requirement for how long a battery will deliver reliable power to our panels. But longer is really better.  

[Fly Boomer]

3 hours ago, cliffy said:

Starting the engine is a secondary purpose for the battery, keeping your panel alive with an alternator failure is the primary use.

My Opinion:  Healthy engine will still start long after the battery would have failed a capacity check.

[Brian E.]

On 7/17/2023 at 10:25 AM, Fly Boomer said:

How many hours has the Gill lasted so far?

I’m 700 hrs on the hill. It has survived 2 generator failures as well

[Fly Boomer]

11 hours ago, Brian E. said:

I’m 700 hrs on the hill. It has survived 2 generator failures as well

That's impressive.  I have no personal experience, but have read here on MooneySpace that some have had early failures.

[Joshua Blackh4t]

I'll be needing a new battery soon and looked into the earthx.

The weight and balance would be great for me, and lithium is more forgiving if its stored at 3/4 full (part of what hurt my Gill is filling up at the nearest bowser, having a difficult hot start, then flying 10minutes home).

BUT it won't work with the old generator. Needs an alternator.

I think I'll just wire in a charge connection point and keep it charged and hopefully will last longer this time.