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  #41  
Old 01-26-2012, 08:02 AM
bigginsking bigginsking is offline
 
Join Date: Aug 2005
Posts: 36
Arrow Beware

So I've been doing some research on these LiFePO batteries. I talked with a FAA electrical Designated Engineering Representative. He points out that although the LiFePO batteries are safer than other Li chemistries, when they fail they still put out electrolyte that is about as flammable as gasoline; whereas other Li chemistries put out gas that ignites immediately when in contact with oxygen.

Yes, this is completely contrary to what wikipedia says about LiFePO. Check out this guy's experience.


As a mitigation you could put the battery in a stainless steel box in the same way you put a stainless firewall between you and the engine. With this setup you have to make sure that the box is well ventilated with a 1.5 inch DIA tube to the exterior recommended. The failure mode can be explosive so the fire isn't contained it can cause shrapnel on top of the fire hence the large vent recommendation.

The DER also points out that even tiny cell phone batteries have a fire ball 2-3 feet in diameter when they fail, you can imagine the fire ball with a battery like we're talking about here. Also people point out the low failure rate of cell phone and laptop batteries but they are in relatively low charge and discharge situation unlike cranking an engine which makes them more susceptible to failure.

So it may make more sense to use these batteries for backup batteries rather than cranking batteries. I run 2 PC625s, one for cranking and one for emergency backup so I could still save 10 lbs.

I'd like to see someone take a Shorai battery and make it fail to see what the failure mode looks like. How long does it burn, how hot does it get, then a box could be designed to contain the potential fire.

Keep all this in mind as you experiment with these batteries, everybody wants to save 20 lbs and this sounds really promising but I don't want to see anyone get hurt.

Bill
N84WJ, RV-8, 700 hrs
http://rv-8.blogspot.com/
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  #42  
Old 01-26-2012, 09:41 AM
wings05rv6a wings05rv6a is offline
 
Join Date: Oct 2006
Location: Coarsegold Ca.
Posts: 71
Default Lithium Aviation Battery

I just spoke with Andy Reich of Lithium aviation battery's. Seems to be very knowledgeable about his product and is very willing to get some feedback. He wants to join the vans air force community, I referred him to Dough Reeves.

Soooh! I ordered a new battery from him at cost of $375.00 and $10.00 for shipping. I will post further info after installation and evaluation. I like that I do not have to create a new battery box and the weight savings is substantial. The replacement battery weigh's 3 Lbs.

Bob Wieczorek
RV6a
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  #43  
Old 01-26-2012, 01:38 PM
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rocketbob rocketbob is offline
 
Join Date: Jun 2006
Location: 8I3
Posts: 3,564
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Quote:
Originally Posted by bigginsking View Post
Yes, this is completely contrary to what wikipedia says about LiFePO. Check out this guy's experience.
I did read that before buying the Shorai's. If you read the article he clearly states that he had regulator problems and this was on top of a defective battery from the factory.
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N9187P PA-24-260B Comanche, flying
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N244BJ RV-6 "victim of SNF tornado" 1200+ hrs, rebuilding
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  #44  
Old 01-26-2012, 01:44 PM
mikerkba mikerkba is offline
 
Join Date: Sep 2008
Location: Ely, Nevada
Posts: 223
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"...he clearly states that he had regulator problems and this was on top of a defective battery from the factory."

I wonder if they could fit all that on my headstone.
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BUILDER: N92MB RV7A (A/W 3/2009) - Sold
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Building: S-21 Outback/Titan, tail and cockpit mated (3/2020)
KELY/Ely, NV
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  #45  
Old 01-28-2012, 05:19 AM
falconev falconev is offline
 
Join Date: Jan 2012
Location: tallahassee FL
Posts: 7
Default Lithium batts

I dont see any internal circuitry inside a shorai battery when I took it apart.
I checked warranty on both shorai and Ballistic. Neither warranties their battery if used in aircraft they said.
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  #46  
Old 03-14-2012, 05:40 PM
HotDoc HotDoc is offline
 
Join Date: Oct 2011
Location: Germany
Posts: 7
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Hi Bob,

how far did you get with your lithium battery installation?

We want to finish our RV7 in autumn and consider a lithium battery as well. However, as a model-aviator I do know that not every lithium-battery is the same.

Thanks,

HotDoc


Quote:
Originally Posted by wings05rv6a View Post
I just spoke with Andy Reich of Lithium aviation battery's. Seems to be very knowledgeable about his product and is very willing to get some feedback. He wants to join the vans air force community, I referred him to Dough Reeves.

Soooh! I ordered a new battery from him at cost of $375.00 and $10.00 for shipping. I will post further info after installation and evaluation. I like that I do not have to create a new battery box and the weight savings is substantial. The replacement battery weigh's 3 Lbs.

Bob Wieczorek
RV6a
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  #47  
Old 08-01-2012, 03:54 PM
humptybump humptybump is offline
 
Join Date: Feb 2011
Location: USA
Posts: 3,179
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Bringing this old thread back because I am starting a test with an LiFePO4 battery. I'll post results as I get them.

To start, the test platform is my RV-8 150hp Lycoming O320-E2A with a Catto 2-blade propeller. The power plant has a 12lb inertia ring installed. The panel is day/night VFR with AP, GPS, and electric DG and AI. It is a typical airplane with typical loads for starting and flight operations.

The reason for my test is that the current battery is an Odyssey PC680 and it has been acting weak - initial crank stops at first compression for 1/2 a second or more and then pulls through with starting typically after 5-8 blades. The battery is 5 years old so it seemed a good place to start.

Since the airplane is almost exclusively day-VFR at the moment, I went with the Shorai LFX18L1-BS12 (12v 18Ah 270 CCA). The battery's specifications are slightly better than the Odyssey 680.

When I start a panel upgrade, I can add a second battery with split circuitry for redundancy.

Testing will be delayed a few days (I don't want to make the switch and immediately head out on a long flight) but I wanted to queue this up in case there are specific data points people want me to collect.


First impression is the physical size of the battery - IT IS TINY. 2.6" x 5.8" x 4.1" and is very light at 2.1lbs. It seems like its a toy because it is so small and so light.

Price for a new Odyssey PC680 was $116 vs price for a new Shorai LFX18L1-BS12 was $160.

Weight for a new Odyssey PC680 was 15.4 lbs vs weight for a new Shorai LFX18L1-BS12 was 2.1 lbs.

For those the do the "price of weight savings" game, that is $3.25 per pound.

Last edited by humptybump : 08-01-2012 at 07:13 PM. Reason: corrected my dyslexic math
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  #48  
Old 08-01-2012, 04:31 PM
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DCat22 DCat22 is offline
 
Join Date: May 2009
Location: Houston, TX
Posts: 531
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Quote:
Originally Posted by rocketbob View Post
I did read that before buying the Shorai's. If you read the article he clearly states that he had regulator problems and this was on top of a defective battery from the factory.
First time reading that....

The follow-up actually leaves me feeling better than had it not happened. Here, and below: http://www.superhawkforum.com/forums...4934/page2/#32
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  #49  
Old 08-01-2012, 04:40 PM
Clark Clark is offline
 
Join Date: Oct 2009
Location: Victoria BC, Canada
Posts: 13
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Hi Glen

Forgive me if I didn't see it, but you didn't state what kind of starter you have. You are describing "to a T" an issue that I have with the older Skytech LS- The bump, pause, then crank

I changed my LS for the new style Skytech NL "in-line" and the problem went away. I too suspected my battery and swapped that out before swapping out the starter - Improved, but still did the pause & crank

If you have a Skyteck SL you may want to consider changing it to a NL.

Best of Luck,
Clark
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  #50  
Old 08-01-2012, 04:45 PM
humptybump humptybump is offline
 
Join Date: Feb 2011
Location: USA
Posts: 3,179
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Thanks Clark, I'll check the starter when I swap in the new battery.

UPDATE: Just looked at the paperwork (then had a peek under the cowl). The plane has a Magnaflite MZ-6204 starter.

Last edited by humptybump : 08-01-2012 at 07:16 PM.
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