New Tech Batteries

[65eTurbo]

My battery is failing, So time for a new one.  

 Last time I was at an automotive battery store I saw the new ultra light weight replacements. I asked my A&P about them and it sounds like they're some that are absurdly expensive and require a separate panel mount monitor but some that are almost 20 pounds lighter than a lead acid but don't need a monitor.   Has anybody going down this route?   I wouldn't mind extra 20 pounds of useful load and I tend toward tail heavy anyway and my battery is in the tailcone...

[carusoam]

In the experimental world…. Yes.

In the certified world, we have the choice of Gill Vs. Concorde…

Gill has the tradition of being terrible… recently they have delivered improvements with their Gel Cell batteries…

There aren’t many pireps around here for them…

This question has come up before, search and see if you can find anything…

It would be really interesting if anyone gets one certified….  It’s been a while since they were introduced…

Either way, my batteries aren’t heavy enough… makeing them lighter causes a different WnB challenge… fixed by adding Charlie weights…

Best regards,

-a-

[Rwsavory]

Even if it were an option, there is no need just to save a few pounds. Suggest you get a Concorde and fly on.

[LANCECASPER]

8 hours ago, 65eTurbo said:

My battery is failing, So time for a new one.  

 Last time I was at an automotive battery store I saw the new ultra light weight replacements. I asked my A&P about them and it sounds like they're some that are absurdly expensive and require a separate panel mount monitor but some that are almost 20 pounds lighter than a lead acid but don't need a monitor.   Has anybody going down this route?   I wouldn't mind extra 20 pounds of useful load and I tend toward tail heavy anyway and my battery is in the tailcone...

To answer your question, yes they are available for some applications, but as mentioned, very expensive. There are other much less expensive ways of losing 15-20 lbs. 

https://www.mcico.com/batteries-1/6430017-1-1

[Guest]

F Atlee Dodge has an STC to install an Odessey battery in some airframes. Is this a basis for a field approval for you guys?

https://fadodge.com/battery-rack-firewall/

Clarence

[GeeBee]

I have seen some bad outcomes with Lithium batteries, even the EarthX type. One includes a nasty fire and crash. Lithium in GA is not ready for prime time.

 

 

[EricJ]

FWIW, those little batteries have been popular in race cars for years due to the reduced weight.   It just has to be big enough to start the car, is the idea.    Reliability has not been great, though, and some have been frustrated enough to just go back to a more traditional AGM and rearrange ballast instead.

I don't think they're quite ready for certified airframes yet, but that's just me.

 

[N201MKTurbo]

I designed a system for charging lithium batteries for surgical instruments (a hundred at a time). I learned a lot about those batteries while doing that.

The problem is trying to make a drop in replacement for a lead acid battery. Lithium cells are very fragile with respect to over charging and over discharging. They need to be carefully controlled especially during rapid charging like what happens after starting your engine. 
 

A proper battery management system would need to control the alternator so it could have fine control of charge voltage and current and a a battery disconnect relay to disconnect the battery to prevent over discharge. 

[Jerry 5TJ]

 TrueBlue has been successful with its lithium battery series.  They combine the battery with a complete BMS and have STC for a number of airframes. 

The weight of their battery is usually about 60% of the lead-acid battery replaced, but it has higher capacity and several times the expected life.  

The only piston single listed on their site with an STC is the A36 Bonanza.  At 8 AMU it isn’t cheap.  

[65eTurbo]

Thanks for the rundown.  I had just assumed all of the lead acid replacements had battery management systems integrated.  As these things get to scale in automotive applications I can't imagine that the power electeonics are that expensive. My A&P is digging around for options for a field approval. He is planning some for a Lear 60 and another application, and looking at field approval options.  I'll report back what he finds.  20 pounds for a few hundred bucks makes sense. For a few grand, not so much.

[carusoam]

Saving that kind of weight…

In a long body…

Would be helpful for a few people…

That want to have….

• A/C
• O₂
• Fiki anti ice

All at the same time…

The bay where all of this stuff resides is the home of the Charlie weights… and batteries….

The Charlie weights come out each time one of the other three things gets installed…

A/C and Fiki don’t typically get installed in the same plane… because there aren’t enough Charlie weights to throw overboard….

 

Having a much lighter battery starts making sense for the LB pilot that wants them all….

 

There are plenty of short body Mooneys with the battery mounted on the firewall still…. A lighter battery up there may make some sense…. 
 

Mounting batteries in front of the firewall under the cowling probably isn’t very good for their health…

 

If somebody pays 8amu for a battery… when a pair of Concordes retails for 1.2amu…

How can this be that important?

How many more gallons can I bring along?

How many more snacks can I bring in the cabin?

 

Just wondering if there is a serious driving force for this technology…

In race cars, every pound counts…

In Mooneys, I can still bring three of my closest friends…. We count the pounds from a WnB point of view…

I think I need about 100Lbs more for a significant increase in weight….

• Another hour of flight
• Another kid in the back
• All sitters to have winter clothes

PP thinking out loud…

-a-

[A64Pilot]

Lithium is a catch all name, like plastic is.

There are many, many different Lithium chemistries,and even in those chemistries, “doping” has become common (doping is adding a chemical to increase performance) so even in the basic groups there are now subgroups.

So point is you can’t group all Lithium batteries together, there are large differences in them.

LifePo4 is a very, very safe chemistry, it was invented by the good folks in Tx, but somehow China owns the patent and therefore the source of almost all Lifepo4 cells is China, but I believe that patent runs out this year.

The price of Lifepo4 cells is less than $80 per KWH, and surely 1KWH is enough (54 KWH will drive our Tesla 270 miles)

So Lifepo4 aircraft batteries will come, my bet is the first affordable viable replacement will have a Concorde label on it as they are currently manufacturing them for the Military, US Navy I believe, and the Navy is the most conscious of all the branches on fire.

A Lifepo4 battery could be like an LED light, that is one may well last the life of the aircraft as they can last up to 10,000 cycles and my suspicion is that reason may be why we don’t have them now, there has to be a lot of business in replacements, and if you made a battery that was so good it never needed replacing, thst may really hurt your bottom line?

[Jerry 5TJ]

If a certified Li battery system is a drop -in replacement, weighs half as much, has more capacity and lasts 5-10 times as long as the lead-acid bricks we use now then 10x the price sounds pretty good, and 3 times more costly would be great.  

[GeeBee]

1 hour ago, A64Pilot said:

Lithium is a catch all name, like plastic is.

There are many, many different Lithium chemistries,and even in those chemistries, “doping” has become common (doping is adding a chemical to increase performance) so even in the basic groups there are now subgroups.

So point is you can’t group all Lithium batteries together, there are large differences in them.

LifePo4 is a very, very safe chemistry, it was invented by the good folks in Tx, but somehow China owns the patent and therefore the source of almost all Lifepo4 cells is China, but I believe that patent runs out this year.

The price of Lifepo4 cells is less than $80 per KWH, and surely 1KWH is enough (54 KWH will drive our Tesla 270 miles)

So Lifepo4 aircraft batteries will come, my bet is the first affordable viable replacement will have a Concorde label on it as they are currently manufacturing them for the Military, US Navy I believe, and the Navy is the most conscious of all the branches on fire.

A Lifepo4 battery could be like an LED light, that is one may well last the life of the aircraft as they can last up to 10,000 cycles and my suspicion is that reason may be why we don’t have them now, there has to be a lot of business in replacements, and if you made a battery that was so good it never needed replacing, thst may really hurt your bottom line?

Not even the LIPo manufacturers are quoting those kind of numbers in high discharge applications. They will also tell you they can overheat and catch fire. Their main advantage is a solidified electrolyte.

 

[Warren]

EarthX is working through the paperwork to extend their certified Models to include Mooneys.  I used my plane (M20K, 12V) for the cranking tests and capacity tests.  Probably still a few more months until the FAA signs off.  Removing a 32lb battery and replacing it with a 5.5lb battery will be one of the cheapest useful load increases possible.

[rbp]

1 minute ago, Warren said:

Removing a 32lb battery and replacing it with a 5.5lb battery

warning, this will make your plane slower in cruise! 

seriously, though, i wonder how it will change the handling/CG to remove 53# from the tail. might require different T/O trim 

[65eTurbo]

Anyone try a field approval on one of these?  STC already for a Cessna single.  Less than 1 AMU to pick up 20 pounds of useful load.

https://earthxbatteries.com/shop/etx900-tso

 

[A64Pilot]

9 hours ago, GeeBee said:

Not even the LIPo manufacturers are quoting those kind of numbers in high discharge applications. They will also tell you they can overheat and catch fire. Their main advantage is a solidified electrolyte.

 

Starting is just a few seconds, it’s not the same at all as continuous high discharge, Lifepo4 is almost impossible to make catch fire. It’s downside is it’s much less energy dense than most lithium chemistries, but is catching up. 

All the standard range Tesla’s as of the beginning of this year are now Lifepo4 banks, the other cars are still NCA as LofePo4 long range banks would be too heavy.

Either way cycle life is almost irrelevant as a starter bank isn’t really cycled, yes there is a rather large current draw but the time interval is so short that there is actually very little Amp Hours removed.

Read this, it may help

https://www.batterystuff.com/kb/articles/battery-articles/lithium-battery-overview.html

[65eTurbo]

3 hours ago, rbp said:

warning, this will make your plane slower in cruise! 

seriously, though, i wonder how it will change the handling/CG to remove 53# from the tail. might require different T/O trim 

 True.  I hate to do it for that reason but the useful load is pretty nice and I'm already at the very back edge of the envelope.  When I fly up to Oshkosh with my 2 boys,   I put the gear in the back seat instead of the luggage area.  I'm going to run the scenario but I think this will work out just fine.  There is some stuff in my current pilot bag that will wind up tied down to the floor in the luggage area instead.   

[rbp]

sound plan! 

[GeeBee]

48 minutes ago, A64Pilot said:

Starting is just a few seconds, it’s not the same at all as continuous high discharge, Lifepo4 is almost impossible to make catch fire. It’s downside is it’s much less energy dense than most lithium chemistries, but is catching up. 

All the standard range Tesla’s as of the beginning of this year are now Lifepo4 banks, the other cars are still NCA as LofePo4 long range banks would be too heavy.

Either way cycle life is almost irrelevant as a starter bank isn’t really cycled, yes there is a rather large current draw but the time interval is so short that there is actually very little Amp Hours removed.

Read this, it may help

https://www.batterystuff.com/kb/articles/battery-articles/lithium-battery-overview.html

From one of the largest LiPo manufacturers:

Their overall life span is comparatively much shorter (about 500-800 charge cycles), especially when used in high demand applications, ie, high discharge lipo battery(250-500 charge cycles).

Also, because of the complicated and much sensitive chemistry involved, these batteries require special care and attention while storing, charging and discharging throughout their life span.

To say the least, if good and proper care is not taken, then Lithium Polymer Battery can lead to explosions also. Also because of the safety issues, they have been classified as dangerous goods by the shipping companies making their shipping expensive and difficult.

Also, they are quite expensive as compared to the other NiCad and NiMH batteries."

https://www.dnkpower.com/lithium-polymer-battery-guide/#chapter3

Now what happens when they explode? They burn quite vigorously, because the lithium is exposed to air. That is why almost all airliners carry an airtight Lithium battery containment pouch for electronics, including LiPo batteries.

What happens when an AGM battery explodes? Nothing. No spill, no fire. Nothing. I've had one blow up on my boat. I can attest.

That is why Tesla batteries are armored with Kevlar. Are you prepared for armored battery boxes?

So we are left with a battery that is not robust in absorbing charging transients, has thermal stability issues in high discharge and if the case blows, it burns, really, really hot. 

No thank you.

Their overall life span is comparatively much shorter (about 500-800 charge cycles), especially when used in high demand applications, ie, high discharge lipo battery(500 charge cycles).

Also, because of the complicated and much sensitive chemistry involved, these batteries require special care and attention while storing, charging and discharging throughout their life span.

To say the least, if good and proper careot taken, then Lithium Polymer Battery can lead to explosions also. Also because of the safety issues, they have been classified as dangerous goods by the shipping companies making their shipping expensive and difficult.

Also, they are quite expensive as compared to the other NiCad and NiMH batteries.

[65eTurbo]

43 minutes ago, GeeBee said:

From one of the largest LiPo manufacturers:

Their overall life span is comparatively much shorter (about 500-800 charge cycles), especially when used in high demand applications, ie, high discharge lipo battery(250-500 charge cycles).

Also, because of the complicated and much sensitive chemistry involved, these batteries require special care and attention while storing, charging and discharging throughout their life span.

To say the least, if good and proper care is not taken, then Lithium Polymer Battery can lead to explosions also. Also because of the safety issues, they have been classified as dangerous goods by the shipping companies making their shipping expensive and difficult.

Also, they are quite expensive as compared to the other NiCad and NiMH batteries."

https://www.dnkpower.com/lithium-polymer-battery-guide/#chapter3

Now what happens when they explode? They burn quite vigorously, because the lithium is exposed to air. That is why almost all airliners carry an airtight Lithium battery containment pouch for electronics, including LiPo batteries.

What happens when an AGM battery explodes? Nothing. No spill, no fire. Nothing. I've had one blow up on my boat. I can attest.

That is why Tesla batteries are armored with Kevlar. Are you prepared for armored battery boxes?

So we are left with a battery that is not robust in absorbing charging transients, has thermal stability issues in high discharge and if the case blows, it burns, really, really hot. 

No thank you.

Their overall life span is comparatively much shorter (about 500-800 charge cycles), especially when used in high demand applications, ie, high discharge lipo battery(500 charge cycles).

Also, because of the complicated and much sensitive chemistry involved, these batteries require special care and attention while storing, charging and discharging throughout their life span.

To say the least, if good and proper careot taken, then Lithium Polymer Battery can lead to explosions also. Also because of the safety issues, they have been classified as dangerous goods by the shipping companies making their shipping expensive and difficult.

Also, they are quite expensive as compared to the other NiCad and NiMH batteries.

I buy all that.  

Regarding. Charging, discharging, and thermal management, it is all handled by integrated battery management systems.  The relevant question is not whether the battery has those characteristics, but whether the battery and managemenr module has those characteristics.   This includes shortened life from accidental compete discharge of the system, or overvoltage of the system.

That aside, the failure mode from mechanical damage can be quite spectacular.  If we suppose the manufacturer has hardened the unit against wear and tear, then our incremental risk is an accident so severe that it punctures the battery, and I doubt I'd be surviving that anyway.  New tech is always a risk.  Everyone has their risk tolerance.

 

[carusoam]

6 hours ago, rbp said:

warning, this will make your plane slower in cruise! 

seriously, though, i wonder how it will change the handling/CG to remove 53# from the tail. might require different T/O trim 

there is a brief discussion above…

Our weight and balance is set by the airframe…. We are either in the envelope or out of it…

So…. If your battery is in the back, and it gets many pounds lighter…

Your B is going to slide forwards…

Where the opportunities arise…

Maybe you have something you want to put in the tail… like an O2 system…

If you have one there already…. A bigger one, a lower cost material one, or a Charlie weight may be your solution….

 

Maybe you want to remove a similar weight from the other end…. Like an MT prop on the nose….

 

Essentially we have a history of modifying weight and balance by moving weight around to maintain balance…

Trying to adjust aerodynamics to make balance work is pretty limited, and not conventional….

Nobody is going to like the cost of re-engineering and testing flight controls to go with a modified WnB…. If that is even possible…

 

Long bodies come with a lot of flexibility designed in…. There is a storage area in the back that holds about half dozen interchangeable  things…( from a WnB point of view)

1) O2 system

2) Fiki anti ice

3) A/C

4) batteries

5) Charlie weights

6) lots of remote avionics boxes

These can all be mix and matched in the back… if the batteries get lighter… you might pick up an A/C system….

 

Its not going to be very easy to turn this lighter weight into Useful Load…. Because of its location….

 

It becomes more useful if you can unweight the front of the plane somehow… could be lots of wires and an old ADF in the panel that may be coming out….

 

Battery sales is going to become an engineering position….   
 

PP thoughts only, not an aero engineer…
 

Best regards,

-a-

[65eTurbo]

58 minutes ago, carusoam said:

there is a brief discussion above…

Our weight and balance is set by the airframe…. We are either in the envelope or out of it…

So…. If your battery is in the back, and it gets many pounds lighter…

Your B is going to slide forwards…

Where the opportunities arise…

Maybe you have something you want to put in the tail… like an O2 system…

If you have one there already…. A bigger one, a lower cost material one, or a Charlie weight may be your solution….

 

Maybe you want to remove a similar weight from the other end…. Like an MT prop on the nose….

 

Essentially we have a history of modifying weight and balance by moving weight around to maintain balance…

Trying to adjust aerodynamics to make balance work is pretty limited, and not conventional….

Nobody is going to like the cost of re-engineering and testing flight controls to go with a modified WnB…. If that is even possible…

 

Long bodies come with a lot of flexibility designed in…. There is a storage area in the back that holds about half dozen interchangeable  things…( from a WnB point of view)

1) O2 system

2) Fiki anti ice

3) A/C

4) batteries

5) Charlie weights

6) lots of remote avionics boxes

These can all be mix and matched in the back… if the batteries get lighter… you might pick up an A/C system….

 

Its not going to be very easy to turn this lighter weight into Useful Load…. Because of its location….

 

It becomes more useful if you can unweight the front of the plane somehow… could be lots of wires and an old ADF in the panel that may be coming out….

 

Battery sales is going to become an engineering position….   
 

PP thoughts only, not an aero engineer…
 

Best regards,

-a-

 

[65eTurbo]

All true.  In my  case it is easy load aft of the CG envelope.  Hard to load ahead of it.  20 pounds out of the tailcone would let me move a 30 pound bag to the back seat and carry an extra 3.2 gallons of fuel in my 90 gallon tanks.