EarthX Battery

[MikeOH]

56 minutes ago, Hank said:

As lead batteries age, their capacity decreases--that's why we do a capacity test every year. So what is the capacity of your battery right now? Nobody knows, especially not you when you are in the clouds.

I capacity tested my 5 year old RG35AXC in June and it was just over 90% which translates to 29.7 Ahr.  Nearly twice that of a BRAND NEW EarthX.  While lithium may not age the same as lead-acid batteries it would be pretty naive to think that a 5 year old EarthX is going to maintain 100% of its new capacity.  No, I do not know the exact capacity of my stone-age Concorde nor does anyone know the exact capacity of their bleeding-edge EarthX.  But I'd bet you real money that my 5 year old battery will last longer in the clouds than a brand new EarthX. And by a significant amount.

As a career engineer it just amazes me the lengths that people will go to defend a new technology (yes, aviation approved lithium batteries are new) in the face of demonstrable shortcomings by merely ignoring them!

I'll repeat my list of FACTS posted much earlier before EarthX came here to 'answer questions' (IOW, advertise):

1) Concorde $500,  EarthX $700

2) Concorde 440 CCA,  EarthX 390 CCA

3) Concorde 33 Amp-Hour,  EarthX 15.6 Amp-Hour

4) Concorde Ipp=800 A at -18C, EarthX Ipp=390 A at -18C

5) EarthX weighs 27 pounds less

So, you have no issue with 1 through 4, just ignore them, because, by god you're going to save 27 pounds!! Joy to the World.

And act like 1/2 the time in the clouds is okay because I can't tell you how close to double my Concorde is today? GMAB

[Hank]

You lost me, @MikeOH. I'm a Mechanical Engineer with a Masters Degree in Engineering and 35 years' experience in industry.

What does this mean? Ain't never heerd of it in all my borned days!

4 minutes ago, MikeOH said:

4) Concorde Ipp=800 A at -18C, EarthX Ipp=390 A at -18C

And yes, I would appreciate taking 27 pounds off of my firewall, it will move my forward CG back a little bit, with all kinds of benefits. 

But I'm no early adopter, especially of things that keep me alive in hostile environments, and inside a cloud a mile or two above ground can be very hostile. I very much enjoy waiting for newness to wear off, and the beta test results from the early adopters to be reviewed and better-functioning revisions to come out. Pricing is usually better then, too.

[MikeOH]

3 minutes ago, Hank said:

You lost me, @MikeOH. I'm a Mechanical Engineer with a Masters Degree in Engineering and 35 years' experience in industry.

What does this mean? Ain't never heerd of it in all my borned days!

And yes, I would appreciate taking 27 pounds off of my firewall, it will move my forward CG back a little bit, with all kinds of benefits. 

But I'm no early adopter, especially of things that keep me alive in hostile environments, and inside a cloud a mile or two above ground can be very hostile. I very much enjoy waiting for newness to wear off, and the beta test results from the early adopters to be reviewed and better-functioning revisions to come out. Pricing is usually better then, too.

It's a parameter that indicates how performance falls off at low temps.  Granted, -18C is a wee bit low...but it's pretty clear that EarthX won't perform as well at cold temps as traditional lead acid types.

Yes, I'm the same way: I prefer others to do the beta testing

One other factor to consider is the possible explosive nature of certain types of lithium battery technologies; no idea if EarthX uses one of them.

I'm sure you've seen the recent video of a guy's Mooney burning to the ground because he dropped a small LiIon battery on the way to his plane and it lit off in the back seat!  Absent hooking up a 12V battery to a 24V start cart situation I've never heard of a lead-acid having that problem!  And, there's been a few Teslas which have gone up in flames when the LiIon batteries malfunctioned!  Seems like one of the new Tesla semi-trucks did the same recently; that one was particularly exciting: I believe they shut down I-80 and diverted traffic until it burned itself out!

Sure, there's a BMS but how much protection does it really provide if it malfunctions?  BMS are fairly sophisticated electronics with many potential failure modes...if it decides to overcharge some cells...do you really want that thing going off in the tail section of your plane?  I'm reasonably certain that they don't take high temps as well as lead-acid which, I think, is the reason they aren't available for install firewall forward.  I am NOT stating that as a fact; someone  can correct that if I'm wrong on that point.

[Graf_Aviator]

I would be interested to know how the EarthX battery is actually behaving during the charging process.

What happens exactly when the battery is empty or close to empty ? Will the BMS limit the amount of amps which go to the battery for charging ?

My understanding is, that an empty or close to empty LiPo or LiFe battery is pulling as many amps as it can get when it is charging back up from a well depleted state. So what happens when there is no limit ? Will the alternator run at full output for an extended time, possibly overheat and burn out ? I am not sure if our stone age alternators are designed to handle the demands of these new batteries... a burnt out alternator will be quite a few AMUs to replace or fix.... 

An AGM or wet cell battery also does pull a lot of amps when it is close to being depleted, but only for a very short time, then the drawn amps will get back down and so does the load level of the alternator.

Thanks, Graf

[Shadrach]

10 hours ago, MikeOH said:

@Shadrach

Is your RG35 rated at less than 33Ahr; I'm struggling to understand how twice the capacity yields you only an additional 15-20 mins?  I'd think if EarthX's 15.6 Ahr gives 1 hour then 33 Ahr would give you at least 2 hours.

The two battery solution with switchover does sound appealing

The RG35A is a 29Ah battery at 100%. I kept my last one until it fell below 80%. The plane does not do a lot of hard IFR. 
Everything is a trade off. So the practical question is, how likely is it that I find myself in a situation where I’m airborne with a dead EarthX that would be alive if it were a Concorde? Seems to me, not very.

Conservatively speaking, the weight difference equates to more than 20mins of fuel at cruise. Statistically speaking it seems to me that more pilots get in trouble exhausting fuel rather than electrons…though I would never do such a thing.

[Shadrach]

9 hours ago, MikeOH said:

I capacity tested my 5 year old RG35AXC in June and it was just over 90% which translates to 29.7 Ahr.  Nearly twice that of a BRAND NEW EarthX.  While lithium may not age the same as lead-acid batteries it would be pretty naive to think that a 5 year old EarthX is going to maintain 100% of its new capacity.  No, I do not know the exact capacity of my stone-age Concorde nor does anyone know the exact capacity of their bleeding-edge EarthX.  But I'd bet you real money that my 5 year old battery will last longer in the clouds than a brand new EarthX. And by a significant amount.

As a career engineer it just amazes me the lengths that people will go to defend a new technology (yes, aviation approved lithium batteries are new) in the face of demonstrable shortcomings by merely ignoring them!

I'll repeat my list of FACTS posted much earlier before EarthX came here to 'answer questions' (IOW, advertise):

 

1) Concorde $500,  EarthX $700

2) Concorde 440 CCA,  EarthX 390 CCA

3) Concorde 33 Amp-Hour,  EarthX 15.6 Amp-Hour

4) Concorde Ipp=800 A at -18C, EarthX Ipp=390 A at -18C

5) EarthX weighs 27 pounds less

So, you have no issue with 1 through 4, just ignore them, because, by god you're going to save 27 pounds!! Joy to the World.

And act like 1/2 the time in the clouds is okay because I can't tell you how close to double my Concorde is today? GMAB

I expect a manufacturer to make a case for their product to their target audience. I take issue with misrepresentation. I have not seen any misrepresentations made.  
Prior to the availability of AGM batteries, most of us had Gill G35s that weighed 27lbs, had just 250 CCA and a capacity of 23AH. The Gill batteries I used for most of my flying had a shelf life slightly better than pasteurized milk. Perhaps, for this reason, I’m not as concerned with rated capacity as you are. 

I’m not entirely sold by any means, but I am intrigued. I also think the BMS offers some beneficial features that aren’t currently available with other applications e.g. over discharge protection.  I think they would do well to enhance BMS info beyond a flashing LED.

[Shadrach]

13 hours ago, jetdriven said:

 So I got the cowl back on, one man style, and I went inside and washed up and then the line guy is like I’ll walk you out. He said well if you start up and it’s charging what are you gonna do and I said I’m going to Oshkosh. He said if you start up and it’s not charging what are you gonna do, I said I’m going to Oshkosh. I cranked it up, it’s charging, I went. But VFR you can go a long  way to someplace more conducive to get some repairs than Chicago PWK executive signature at 5 PM on a Sunday. 

I diverted into Allentown/Queen City after a gen failure on my way back form Manchester.  I had the local mx facility charge the battery overnight and I reinstalled it the next morning.  I launched for home in clear VFR weather planning to arrive in under an hour. Before departing, I called my home tower to tell them my approximate ETA and that I may have a comm issue upon arrival necessitating light signals.  I flew home with a handheld GPS and the master off, powering up from the Harrisburg TRSA (Now Class C) to HGR.  I had adequate power to complete the trip with no issue.  A CFI friend suggested that departing with defective, required equipment could get me in hot water with the FSDO. 

[Graf_Aviator]

I would be interested to know how the EarthX battery is actually behaving during the charging process.
What happens exactly when the battery is empty or close to empty ? Will the BMS limit the amount of amps which go to the battery for charging ?
My understanding is, that an empty or close to empty LiPo or LiFe battery is pulling as many amps as it can get when it is charging back up from a well depleted state. So what happens when there is no limit ? Will the alternator run at full output for an extended time, possibly overheat and burn out ? I am not sure if our stone age alternators are designed to handle the demands of these new batteries... a burnt out alternator will be quite a few AMUs to replace or fix.... 
An AGM or wet cell battery also does pull a lot of amps when it is close to being depleted, but only for a very short time, then the drawn amps will get back down and so does the load level of the alternator.
Thanks, Graf

@EarthX Inc Could you please share some insight on this ?
Thank you


Sent from my iPhone using Tapatalk

[EarthX Inc]

46 minutes ago, Graf_Aviator said:

@EarthX Inc Could you please share some insight on this ?
Thank you


Sent from my iPhone using Tapatalk

Hi Graf,

If your battery is almost empty or fully drained, it will not have enough energy to start your plane.  It should be charged before takeoff with a plug in the wall charger, regardless of what type of chemistry battery you have. 

However, if your lithium battery is slightly depleted and your alternator is topping it off after starting, this is from our FAQ seciton of the website:

I just installed my EarthX battery in my aircraft and started the engine and my charging amps was really high, is this normal?

Yes, this is normal. A lithium battery can and will accept a much higher charging current than an equal size lead acid battery. If your battery is not fully charged, your alternator can potentially output a current equal to or slightly above the alternator’s rating for a few minutes to top the battery off. 

 

As far as your questions about your alternator, I would recommend you reach out to your alternator manufacturer and ask them what happens if the alternator is putting out its rated amperage as they will be the experts on answering that question. 

 

[exM20K]

While the @EarthX Inc solution may not be the best for everyone, I believe it has great potential for the long body / fiki planes.  My Acclaim has two RG24-15 batteries in the back not for backup power so much as balance.  I am much less concerned about alternator failure (setting aside the havoc that a failed drive can do to a CMI powerplant) because the plane has a standby alternator and emergency bus. 

Installed alongside the Kelly Aerospace A/C  (Note to @Kelly Aerospace, you really need to work on your SEO - had to dig for the website, and only a FB link came up in google), I lose only net 20# of useful load since the A/C sits on the hat shelf, and it would move the CG to the rear, which is a good thing for the M20TN. 

Maybe that will be next spring's project, provided that the Thermacool product isn't subject to Hartzell's "enhanced" pricing like the turbo's are, and that @EarthX Inc has a STC in hand for the M20TN. It would be awesome if these two companies could work out a package deal.

Until then, it's me, my Be-Kool, and 20# of ice, almost the same W&B.

 

-dan

[philiplane]

Here's a fresh data point to consider. Cirrus has adopted the Earth-X battery in the 2024 models.

I have a client with a six-month old SR22, and his Earth-X battery just failed. Probably due to my main complaint, which is the small reserve time compared to conventional batteries.

The newer Cirrus have an app just like newer cars do. (Cirrus IQ)You can check the status of the plane from your phone. The problem is, planes usually reside in hangars, where there may be limited or no cell network. The plane's IQ unit tries to connect with the network, and will continue until the battery is dead. Like any cell phone will do under the same conditions. But with half the reserve capacity of a conventional battery, well, you get the idea. Dead battery, quickly.

It also appears that the Earth-X battery does not come back quickly after using ground power to charge, and then start, the plane. They tried, and had to ferry the plane over to a Service Center to sort out the cascade of failures resulting from the dead battery. I think they'll be replacing it with a good old Concorde RG24-11M. Unfortunately, Cirrus changed the battery tray when adopting the Earth-X. So if your lithium battery dies on the road, you are stuck until a new one can be delivered. Like anything new, getting replacement parts can add to the downtime. 

[EricJ]

53 minutes ago, philiplane said:

It also appears that the Earth-X battery does not come back quickly after using ground power to charge, and then start, the plane. They tried, and had to ferry the plane over to a Service Center to sort out the cascade of failures resulting from the dead battery. I think they'll be replacing it with a good old Concorde RG24-11M. Thankfully, Cirrus did not downsize the battery tray when adopting the Earth-X. They used a filler to adapt the baby battery to the standard tray, so you can take that filler out and put a real battery back in.

Is Cirrus paying for that or is that on his dime?

[BlueSky247]

That sucks about the Cirrus.

 

To be completely fair, that's not an EarthX problem. That's a poor design/engineering choice on the part of Cirrus. Any kind of "connected" system should have a safe guard monitoring it's supply voltage so that it doesn't cripple the host. At the price level we are talking, not having that kind of safety net designed in is inexcusable. 

[EricJ]

1 hour ago, BlueSky247 said:

That sucks about the Cirrus.

 

To be completely fair, that's not an EarthX problem. That's a poor design/engineering choice on the part of Cirrus. Any kind of "connected" system should have a safe guard monitoring it's supply voltage so that it doesn't cripple the host. At the price level we are talking, not having that kind of safety net designed in is inexcusable. 

I'd guess that's a configurable item that could be disabled, or at least it should be, but I'm curious about this as well.   In cellular systems they learned long ago to run only the receiver until a cell site is heard, and most systems that require authentication or provisioning do it this way now.   Since the transmitter typically uses significantly more power than the receiver, this minimizes battery consumption.   Many systems will go to sleep completely and just wake up periodically to see if anything that they can talk to has come within range.

So, yeah, a modern communication system that can drain a large-ish battery in a short time seems odd, and I'd think would be either a misconfiguration or some seriously bad engineering choices.

[Shadrach]

21 hours ago, BlueSky247 said:

That sucks about the Cirrus.

 

To be completely fair, that's not an EarthX problem. That's a poor design/engineering choice on the part of Cirrus. Any kind of "connected" system should have a safe guard monitoring its supply voltage so that it doesn't cripple the host. At the price level we are talking, not having that kind of safety net designed in is inexcusable. 

Agreed, it’s silly to blame the battery producer for this issue. My guess is that if it were any other battery, no one would, but let’s beat up on the new tech…

Technology has provided some truly fantastic innovations over the years and then there are things like Cirrus IQ…the factory installed battery depletion system that won’t connect in a hangar but will drain your battery.  

The SR series app tells you the following:

• Fuel on board
• O2 fill level (if applicable)
• TKS Level (if applicable)
• Battery Voltages 
• Battery Temp

It’s amazing that pilots of other makes have managed for so long without having such information available on their phones…

[EarthX Inc]

23 hours ago, philiplane said:

Here's a fresh data point to consider. Cirrus has adopted the Earth-X battery in the 2024 models.

I have a client with a six-month old SR22, and his Earth-X battery just failed. Probably due to my main complaint, which is the small reserve time compared to conventional batteries.

The newer Cirrus have an app just like newer cars do. (Cirrus IQ)You can check the status of the plane from your phone. The problem is, planes usually reside in hangars, where there may be limited or no cell network. The plane's IQ unit tries to connect with the network, and will continue until the battery is dead. Like any cell phone will do under the same conditions. But with half the reserve capacity of a conventional battery, well, you get the idea. Dead battery, quickly.

It also appears that the Earth-X battery does not come back quickly after using ground power to charge, and then start, the plane. They tried, and had to ferry the plane over to a Service Center to sort out the cascade of failures resulting from the dead battery. I think they'll be replacing it with a good old Concorde RG24-11M. Thankfully, Cirrus did not downsize the battery tray when adopting the Earth-X. They used a filler to adapt the baby battery to the standard tray, so you can take that filler out and put a real battery back in.

Couple of notes, the Cirrus G7 is a 28V aircraft, not 14V.  

The EarthX battery used in the Cirrus has slightly MORE capacity than the Concorde RG24-11M battery, 11.7Ah vs. 11Ah. The Cirrus G7 has many upgraded features, including the IQ app, that needed a higher capacity battery for this reason.  

The EarthX battery has 400 cranking amps vs the 160 cranking amps of the RG24-11M battery and weighs 7.2 pounds, vs. 26.6 pounds, for a 19.3 pounds weight savings.

As this is a Mooney forum, we will refrain going into the details of the features of the new Cirrus G7 but your assumptions that the battery tray is the same is incorrect and that your client will switch it back to a “good old Concorde” and “put a real battery back in” are also incorrect as the G7 is engineered and type certificated using the EarthX battery.  

The “data” point that the battery “just failed” is interesting as part of the RS-232 communications the aircraft has with the IQ app provides real time data and a detailed report of state of charge among many other features, including the health of the battery.  (Again, as this is a Mooney forum, I will refrain from more details) Part of this electrical upgrade does mean the aircraft uses power when shut down and your client should be mindful of this and follow the provided guidance from Cirrus on how this system works.

The statement that there was a “cascade of failures” resulted from the battery being drained is also interesting as the battery has protection built in for something like this and would simply need to be recharged. No damage to the battery or the aircraft system.  

Lastly, you assume that the EarthX battery appears to not come back quickly with use of ground power. This is not correct.  There is no reason it can not be charged from ground power if the correct guidance for the Cirrus aircraft is followed.

We do offer an extensive amount of information on our website designed to help educate and inform potential new customers (and OEM’s) about the EarthX batteries so you can make an informed decision based on factual data.  We offer manuals, FAQ’s, Fact sheets, and we are actively working on providing more video presentations of information for those who do not want to read. We also provide good old school communications, and you can call us at 970.674.8884 ext. 2 so please don’t hesitate to reach out this way if this is what you prefer.

[jetdriven]

If you guys would put those cells in series and parallel and get 30 amp hours out of a 12 V battery you would sell a heck of a lot more of those things.

[Shadrach]

25 minutes ago, jetdriven said:

If you guys would put those cells in series and parallel and get 30 amp hours out of a 12 V battery you would sell a heck of a lot more of those things.

That would make it a 24 V system for which they do not have an STC.

[MikeOH]

1 minute ago, Shadrach said:

That would make it a 24 V system for which they do not have an STC.

I believe @jetdrivens point was they would sell a lot more 12V batteries if they DOUBLED the Amp-hour capacity.  Yeah, STCs will be required.

[Shadrach]

50 minutes ago, MikeOH said:

I believe @jetdrivens point was they would sell a lot more 12V batteries if they DOUBLED the Amp-hour capacity.  Yeah, STCs will be required.

I’ve made that case as well. That could be done by installing two ETX900s in parallel would yield 12V 31.2ah and 780CCA. @EarthX Inc stated that the current would exceed the specs for the starting system. Which is why I suggested a dual battery on a switch.

Installing two ETX900s in series would yield 24V 15.6ah and 390cca.

Installing in series and parallel would yield 

24v 31.2ah and 780cca.

Im not sure why 790cca is a problem, but I’m assuming there is a legitimate concern.

 

[MikeOH]

5 minutes ago, Shadrach said:

I’ve made that case as well. That could be done by installing two ETX900s in parallel would yield 12V 31.2ah and 780CCA. @EarthX Inc stated that the current would exceed the specs for the starting system. Which is why I suggested a dual battery on a switch.

Installing two ETX900s in series would yield 24V 15.6ah and 390cca.

Installing in series and parallel would yield 

12v 31.2ah and 780cca.

Im not sure why 790cca is a problem, but I’m assuming there is a legitimate concern.

 

I suspect, but don't know with certainty, that the original starting 'system' Mooney design could handle a short circuit without 'going up in flames', at whatever peak current the battery is capable of, until the battery was depleted.  I don't believe there is any current limiting/protection device in the high-current path from the battery, through the contactor, to the starter that would protect the wiring.

Hence, too much short term current availability from a battery could be an issue.

[EarthX Inc]

1 hour ago, jetdriven said:

If you guys would put those cells in series and parallel and get 30 amp hours out of a 12 V battery you would sell a heck of a lot more of those things.

Let me try and explain this another way. Amp hour and cranking power are related. In order for Concorde to achieve 390CCA, they needed a 29Ah battery. They did NOT need this much capacity to meet the requirements in the event of an alternator failure.  A lithium battery can have half the amount of amp hours and achieve the same cranking power as a lead acid battery and meet the requirements in the event of an alternator failure.

The EarthX battery is FAA TSO and STC approved.  It has undergone over 161 regulation required testing over the past 5 years and the 15.6 Ah was proven to meet and exceed requirements by a 210% margin for the Mooney’s we have the STC for.

So my question is, what engineering data do you have that supports the need for 30+ amp hour battery?  

Everything about your plane is engineered and designed for a reason. From the length of your wings to the size of your fuel tanks to the engine size, etc.  Having double the gallons of fuel would certainly get you farther distances, so why did they not do that? Having a larger engine or even a turbine would certainly get you more power, so why did they not do that?  

Being a pilot means you need to be aware and follow operating procedures, most certainly the emergency procedures.

Per your POH, in the event of an alternator failure, you are to shed non-essential load and "land as soon as practical" (this verbiage varies slightly depending on the manufacturer of the plane but is consistent for all aircraft).  This does not mean you fly to the farthest airport you think you can reach; it means you land as soon as practical.  It should also be noted, that even if you have an alternator failure in conjunction with a battery failure, (which includes depleting it fully, regardless if it is a lithium battery or a lead acid battery) your plane will continue to fly. 

So again I ask, what engineering data do you have to support the need for 30+ amp hour battery?

 

[MikeOH]

5 minutes ago, EarthX Inc said:

So my question is, what engineering data do you have that supports the need for 30+ amp hour battery?  

So again I ask, what engineering data do you have to support the need for 30+ amp hour battery?

Flying safely is all about good judgement and risk mitigation and is NOT merely about 'engineering data'.

Your continued insistence that having HALF the time available to a pilot should his alternator fail in IMC is somehow perfectly okay is NOT persuasive!  It is a complete antithesis to risk mitigation and the exercise of good aeronautical decision making.  You are making excuses for your product's inferior Amp-hour capacity.

 

[Shadrach]

2 minutes ago, MikeOH said:

Flying safely is all about good judgement and risk mitigation and is NOT merely about 'engineering data'.

Your continued insistence that having HALF the time available to a pilot should his alternator fail in IMC is somehow perfectly okay is NOT persuasive!  It is a complete antithesis to risk mitigation and the exercise of good aeronautical decision making.  You are making excuses for your product's inferior Amp-hour capacity.

 

I don’t have a dog in this fight. I’m merely interested observer. it seems to me your statement is not entirely true. It’s not that the amp hour rating is interior so much is the battery type being used. How do you suggest they create a lifepo4 battery that fits within the systems current (cca) specifications and still has the capacity of an AGM battery? 
 

We live in good times… when our airplanes were delivered they had crappy wet cell batteries that would barely break 250 CCA and 20 ah. 

[jetdriven]

33 minutes ago, EarthX Inc said:

Let me try and explain this another way. Amp hour and cranking power are related. In order for Concorde to achieve 390CCA, they needed a 29Ah battery. They did NOT need this much capacity to meet the requirements in the event of an alternator failure.  A lithium battery can have half the amount of amp hours and achieve the same cranking power as a lead acid battery and meet the requirements in the event of an alternator failure.

The EarthX battery is FAA TSO and STC approved.  It has undergone over 161 regulation required testing over the past 5 years and the 15.6 Ah was proven to meet and exceed requirements by a 210% margin for the Mooney’s we have the STC for.

So my question is, what engineering data do you have that supports the need for 30+ amp hour battery?  

Everything about your plane is engineered and designed for a reason. From the length of your wings to the size of your fuel tanks to the engine size, etc.  Having double the gallons of fuel would certainly get you farther distances, so why did they not do that? Having a larger engine or even a turbine would certainly get you more power, so why did they not do that?  

Being a pilot means you need to be aware and follow operating procedures, most certainly the emergency procedures.

Per your POH, in the event of an alternator failure, you are to shed non-essential load and "land as soon as practical" (this verbiage varies slightly depending on the manufacturer of the plane but is consistent for all aircraft).  This does not mean you fly to the farthest airport you think you can reach; it means you land as soon as practical.  It should also be noted, that even if you have an alternator failure in conjunction with a battery failure, (which includes depleting it fully, regardless if it is a lithium battery or a lead acid battery) your plane will continue to fly. 

So again I ask, what engineering data do you have to support the need for 30+ amp hour battery?

 

Because I want a solid hour of reserve capacity in my plane, and if I load shed aggressively, two.  Important in a single engine plane with only one alternator.