STC for moving the battery location

[Yourpilotincommand]

My empty CG has become a bit aft through the years and would like to move it forward. Does such an STC exist to move the battery up to the engine compartment?

[Robert Hicks]

What model Mooney?

[MARZ]

28 minutes ago, Robert Hicks said:

What model Mooney?

guessing a 66 E 

 

[Old Chub]

Like Robert Hicks I have a C model and just moved mine to the back due to the 3 bladed prop.  The C model (which factory has the battery in the front) has a cut out in the firewall that allows a corner of the battery box to sit just above the foot wells.   Not sure how a E model could make the change or at least like it exists on the C model.  

Warren 

 

[hammdo]

On the iPhone 13 pro I have  I don’t see the model. Have to click on icon to go to details- there it shows the model.

[Hank]

1 hour ago, hammdo said:

On the iPhone 13 pro I have  I don’t see the model. Have to click on icon to go to details- there it shows the model.

Turn your phone to landscape orientation, lots of stuff will appear on the left. At least it does on my Samsung . . . .

[hammdo]

Yep, but I like the additional details ;o)

-Don

[47U]

6 hours ago, Yourpilotincommand said:

My empty CG has become a bit aft through the years and would like to move it forward. Does such an STC exist to move the battery up to the engine compartment?

It might be a unique request to move the battery forward… not aware of any STC to do so.   The first year of E-model production was 1964 and the battery was moved aft while the C and D kept the battery on the firewall.  If your A&P/IA is receptive, you might be able to do it under a minor mod, but if would take a firewall modification to make it fit in the same fashion as  C/D models.  Duplicating the Mooney installation would be optimum for approval by your A&P/IA.

[gmonnig]

If your E is like my 65' then why not upgrade to that EarthX battery? You'll gain 20lbs of useful load and that 20lbs comes from aft of the baggage area. It's a win-win situation 

[Ragsf15e]

9 hours ago, Yourpilotincommand said:

My empty CG has become a bit aft through the years and would like to move it forward. Does such an STC exist to move the battery up to the engine compartment?

Eat some donuts and pizza.  Your cg will fix itself.

[A64Pilot]

You may be the unusual candidate where one of the new high speed light weight LifePo4 battery STC’s are made for. Much less work and expense than moving a battery

You would get some CG shift and pick up useful load too, to know how much of course you need to compute the change in W&B.

I’d be a little suspicious of a too far aft CG though, perhaps weighing the aircraft may be worthwhile, it’s not uncommon for math errors to creep into a W&B over time.

A battery is a heavy thing the shift in CG would be quite substantial if moved to the firewall, maybe more than you would want.

Most seem to like their CG being aft of center as opposed to being forward, aircraft is lighter on the controls and faster, but forward makes for a more stable instrument platform.

[A64Pilot]

14 hours ago, gmonnig said:

If your E is like my 65' then why not upgrade to that EarthX battery? You'll gain 20lbs of useful load and that 20lbs comes from aft of the baggage area. It's a win-win situation 

Sorry didn’t see your post before I posted

[gmonnig]

1 hour ago, A64Pilot said:

Sorry didn’t see your post before I posted

Oh it's all good. We are just thinking the same thing. I agree that you should weigh the plane first to see exactly where the CG is. I am going to follow that same advice. I'm in the process of a full interior refit, once complete I will get it weighed. I'll maybe do the battery STC and/or skytec starter, depending on where the CG is.

[vik]

On 1/6/2023 at 11:52 AM, Yourpilotincommand said:

My empty CG has become a bit aft through the years and would like to move it forward. Does such an STC exist to move the battery up to the engine compartment?

I just mention this in the discussion about the battery, but it might fit the bill for you as well. EarthX LiFePo4 battery is now certified for Mooney. It only weights 5 lbs. Might be the easiest solution, plus you get a new hi-tech battery.

 

[ArtVandelay]

I just mention this in the discussion about the battery, but it might fit the bill for you as well. EarthX LiFePo4 battery is now certified for Mooney. It only weights 5 lbs. Might be the easiest solution, plus you get a new hi-tech battery.
 

I would think a new voltage regulator would be necessary.
Lithium battery can catch fire if overcharged.

[DXB]

1 hour ago, vik said:

I just mention this in the discussion about the battery, but it might fit the bill for you as well. EarthX LiFePo4 battery is now certified for Mooney. It only weights 5 lbs. Might be the easiest solution, plus you get a new hi-tech battery.

 

 

1 hour ago, ArtVandelay said:

I would think a new voltage regulator would be necessary.
Lithium battery can catch fire if overcharged.

I'd never heard of this Iithium EarthX option - it sounds really cool!!  Longer useful life could offset the extra cost, and larger capacity could make it a major safety feature in case of an alternator failure.  And the weight savings is awesome!   It looks like it has its own battery management system to prevent overcharge etc.  Is there any info on the STC for Mooney?  I couldn't find anything online.  Also I wonder how suited it is to the battery box up front in C models, not only fit but also temperature environment, despite the box being ventilated via a tube from the doghouse. My Concorde is pretty new, so need to be an early adopter, but hopefully my next battery in a few years will use this technology.  

[jetdriven]

That EarthX 12V battery only has 15AH of capacity, about half that of the standard lead-acid unit.

[MikeOH]

On 1/6/2023 at 11:52 AM, Yourpilotincommand said:

My empty CG has become a bit aft through the years and would like to move it forward. Does such an STC exist to move the battery up to the engine compartment?

A few questions come to mind:

1) Are you actually flirting with being out of the aft limit??

2) Do you realize that performance is somewhat better with aft CG?

3) If an STC is available, this looks likes some work...read $$$.  What are you hoping to gain?

[Fly Boomer]

1 hour ago, ArtVandelay said:

I would think a new voltage regulator would be necessary.
Lithium battery can catch fire if overcharged.

I don't know about that specific battery, but I think that they all have different characteristics.  Maybe some don't spontaneously burst into flames:

lithium iron phosphate
lithium cobalt oxide
lithium manganese oxide
lithium nickel manganese cobalt oxide
lithium nickel cobalt aluminum oxide
lithium titanate

[ArtVandelay]

3 hours ago, jetdriven said:

That EarthX 12V battery only has 15AH of capacity, about half that of the standard lead-acid unit.

That’s a deal breaker.

[The Other Red Baron]

The EarthX STC is a little confusing looking at M20E

https://earthxbatteries.com/list-of-stcs/

From the googling I've done aka this single page:

https://www.mooneyevents.com/chrono.htm

Mooney never had E models with the 24- prefix. What am I missing?

 

[carusoam]

1) Check the WnB carefully…

2) Know that batteries went to the back for some good reasons…

3) Cooking a high tech battery in front of a firewall… I wouldn’t want to be first….

4) It gets pretty hot under the cowl in the summer some days… does the Earth-X have any guidance for that?

5) Most batteries don’t like either really hot or really cold…

6) Battery life is going to be important…

7) +1 for knowing your battery capacity… if you have half the battery capacity… check the certification closely…

If you fly in IMC, and lose your alternator… what happens next? How long do you have?

Some detail seems to be missing…

VMC conditions and the next airport might be a long ways away… your batteries need to get you there…

Does your back-up AI have enough battery power of its own?

So many variables in this mix… 

Best regards,

-a-

[Greg Ellis]

On 1/8/2023 at 1:55 PM, DXB said:

 

I'd never heard of this Iithium EarthX option - it sounds really cool!!  Longer useful life could offset the extra cost, and larger capacity could make it a major safety feature in case of an alternator failure.  And the weight savings is awesome!   It looks like it has its own battery management system to prevent overcharge etc.  Is there any info on the STC for Mooney?  I couldn't find anything online.  Also I wonder how suited it is to the battery box up front in C models, not only fit but also temperature environment, despite the box being ventilated via a tube from the doghouse. My Concorde is pretty new, so need to be an early adopter, but hopefully my next battery in a few years will use this technology.  

I am not going to get an EarthX battery however, I did contact the company about their batteries being up in the engine bay and the heat that it may incur in that area.  My question specifically asked "In some Mooney aircraft, the battery is located within the engine area in front of the firewall. It tends to get hot in there. Will the EarthX battery have an issue in such an environment?"  This was their response for any interested:

So typically no but there are specific cases where the temps exceed our batteries limitations and our fault LED will signal a 2 second on 2 second off fault which means high temperature. I suggest connecting our LED to your EFIS or our LED kit so you can monitor it. If it was to be an issue there are 2 options that you could do. You could move the battery box but that can be a lot of work which is why we make a thermal battery box you could use and or as well as heat shielding the battery yourself possibly adding a blast tube if needed.

Keagan

Technician | Earth X

EarthX Lithium Batteries - YouTube

[kris_adams]

Like @jetdriven pointed out...the new lipo4 battery is 15.6ah, my rg-35axc (pretty sure that's the model) is 33ah.  Man, I'd love to gain the +27 pounds of useful load.  I love the lipo4 battery in my golf cart, but I did have an older technology lithium battery melt down on a motorcycle.  One day I'll have one in the plane but I'm still a bit nervous.

[1980Mooney]

On 1/6/2023 at 1:52 PM, Yourpilotincommand said:

My empty CG has become a bit aft through the years and would like to move it forward. Does such an STC exist to move the battery up to the engine compartment?

 

On 1/8/2023 at 2:12 PM, MikeOH said:

A few questions come to mind:

1) Are you actually flirting with being out of the aft limit??

2) Do you realize that performance is somewhat better with aft CG?

3) If an STC is available, this looks likes some work...read $$$.  What are you hoping to gain?

I am curious how the CG moved materially aft on your 1966 M20E. (As asked above are you flirting with limit?) - did you gut the original panel with a complete upgrade?  Composite prop? Lightweight starter or other accessories? If so that would seem to be advantageous Because since 1966 the true front seat pilot/copilot weights have materially increased. 

If you haven’t made any big changes then perhaps there is a W&B calc error

 

Edited January 9, 2023 by 1980Mooney