Lithium Batteries?

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Lithium Batteries?

Postby SheepdogRD » Sun Jan 29, 2012 11:20 am

I've been scouting the batteries available for us. I liked the look of Steve Henry's Shorai battery -- high power in a package that weighs only a couple of pounds. Then on the Jab Owner's Group on Yahoo, there was this comment about a similar battery:

"The Antigravity batteries look great, and very cheap on basis of dollars per pound saved, BUT they seem to be lithium batteries, which includes potential for fire. Okay if on a dirt bike or small race car that one can bail out of in a hurry if needed, but not for me in an airplane. -- David A"

I know that lithium batteries can spontaneously combust under certain circumstances; examples are laptop batteries that have caught fire and prompted recalls. Apparently, these fires are produced by design flaws. I also know that lithium burns fast and hot.

I'm told that TSA rules severely restrict the transport of lithium batteries, and that they are not supposed to be in the hold, only in the passenger compartment where any problems can be dealt with directly. (No, I'm not holding TSA out to be a model of a wisely-run agency, but still, there may be a basis for this very specific prejudice.)

[EDIT:] The Shorai batteries are lithium iron phosphate (LiFePO4) units. What I've seen in looking around on the WWWeb is that LiFePO4 batteries -- like the Shorai -- are much LESS of a fire hazard than lithium-ion batteries we carry in our computers. [/EDIT]

[EDIT 2:] The author of the quoted comment above made this additional remark the next day: "Have to take back part of my comment on the Antigravity lithium battery. Just had a couple of e-mail exchanges with Scott- of Antigravity Co. (on a Sunday yet) who points out that their battery is Lithium Iron Phosphate which is supposedly a "safer" than Lithium Ion. Reports some being used in ultra lights. Discussions of suitability for this application and compatibility with Jab alternator and regulator and under cowl location continue. He recommends 16 or 20 cell version to replace a PC680. Expensive battery, but cheap when considering cost per pound saved which is about 10 or 11 pounds. I would add back at least a pound of that for a second layer of SS firewall behind it though. For now, at least a development to watch. -- David A" [/EDIT 2]

Do we have any battery jocks who can comment on the relative safety of these lithium batteries? If they seem to be safe enough, what precautions do we need to consider in installing and using them?
Last edited by SheepdogRD on Mon Jan 30, 2012 10:34 am, edited 2 times in total.
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Re: Lithium Batteries?

Postby danerazz » Sun Jan 29, 2012 4:47 pm

Just based on my experience with r/c models and LiPo batteries, here are the known things that can cause a spontaneous fire:

Over charging/charging at too high of rate
Over discharging, too high of rate or too low of voltage
ANY physical damage to the cell will cause an instant, catastrphic fire
Overheating for any reason (over charge/discharge, etc.)

Overheating of a "soft" pack will cause it to permanently bulge, and it will be likely to fail in some way or another with subsequent use. Also, generally you need a special charger to charge a lithium battery, as they need carefully regulated voltage/current. This makes charging by an alternator an issue (may need an actual charger on board like the old nicad batteries needed before rgb batteries).

There are huge improvements in batteries every year, many are starting to make them more tolerant of charge/discharge issues, and more durable. There also may be some batteries I am not familiar with with lithium chemistry, but this is my current knowledge.

Check YouTube for LiPo battery fire and see how instant and violent a failure can be.
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Re: Lithium Batteries?

Postby xpflyr » Sun Jan 29, 2012 6:14 pm

SheepdogRD wrote:I've been scouting the batteries available for us. I liked the look of Steve Henry's Shorai battery -- high power in a package that weighs only a couple of pounds. Then on the Jab Owner's Group on Yahoo, there was this comment about a similar battery:

Do we have any battery jocks who can comment on the relative safety of these lithium batteries? If they seem to be safe enough, what precautions do we need to consider in installing and using them?


I'm no Lithium battery expert. Don't know of anyone flying one. But if there's a chance why take it? You chose an engine weighing many more lbs than you have to and then worry about 8 lbs of battery? In my last plane I bought every kind of battery out there. I had a hard starting engine I guess. Until I found and bought the Odyessy dry cell that is. The best battery out there. If you're battery is in the engine compartment go with the smaller one. If it's behind the rear bulk head, like me, go with the bigger one.
http://www.odysseybatteries.com/applica ... rcraft.htm
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Re: Lithium Batteries?

Postby SheepdogRD » Sun Jan 29, 2012 6:47 pm

xpflyr wrote:You chose an engine weighing many more lbs than you have to and then worry about 8 lbs of battery?

Yes, I did. Everything is a tradeoff. The Corvair engine I was planning to use then would have reduced useful load 35 to 40 pounds, and saved a lot of money. If a pair of the lithium iron phosphate batteries would work, I'd get back 11 pounds of that for a few hundred dollars, so it seemed worthwhile to explore it.

I just added this paragraph to the initial post:
The Shorai batteries are lithium iron phosphate (LiFePO4) units. What I've seen in looking around on the WWWeb is that LiFePO4 batteries -- like the Shorai -- are much LESS of a fire hazard than lithium-ion batteries we carry in our computers.
Last edited by SheepdogRD on Fri Feb 01, 2013 12:01 pm, edited 1 time in total.
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Re: Lithium Batteries?

Postby FlyerChief » Sun Jan 29, 2012 7:02 pm

Here's what I've been looking at for my Highlander, but maybe a bit more research is in order. :shock: It's designed as an aircraft battery and with cell balance charger that's available as an extra, maybe it's a lot safer. Seems to me Aircraft Spruce wouldn't sell them if there was a hazard. :roll:
http://www.aircraftspruce.ca/catalog/elpages/aerovoltz4.php

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Re: Lithium Batteries?

Postby SheepdogRD » Sun Jan 29, 2012 7:20 pm

Good find, Dan. That's a weight savings of 12 pounds. At $270 on the AeroVoltz site (and AS will price match that), it's about $100 more than the Odyssey. The charger is $80, and weighs 10 oz.

Call that an 11-pound savings for under $200.
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Re: Lithium Batteries?

Postby FlyerChief » Sun Jan 29, 2012 7:28 pm

It's small enough and light enough that I plan on mounting it in the engine compartment, right on the firewall. Besides... I have other plans for the area where the battery would normally sit. 8)

Cheers,
Dan
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Re: Lithium Batteries?

Postby SheepdogRD » Mon Jan 30, 2012 10:37 am

I just added this to the original post:

The author of the quoted comment above made this additional remark the next day: "Have to take back part of my comment on the Antigravity lithium battery. Just had a couple of e-mail exchanges with Scott- of Antigravity Co. (on a Sunday yet) who points out that their battery is Lithium Iron Phosphate which is supposedly a "safer" than Lithium Ion. Reports some being used in ultra lights. Discussions of suitability for this application and compatibility with Jab alternator and regulator and under cowl location continue. He recommends 16 or 20 cell version to replace a PC680. Expensive battery, but cheap when considering cost per pound saved which is about 10 or 11 pounds. I would add back at least a pound of that for a second layer of SS firewall behind it though. For now, at least a development to watch. -- David A"
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Re: Lithium Batteries?

Postby danerazz » Mon Jan 30, 2012 9:37 pm

One thing to watch is some alternators require a direct connection to a battery so the regulator has a good voltage reference, which may preclude the use of anything requiring a charger (depending on your alternator) though it may be possible to wire it in a way that it could work. I don't know how the chargers work with the typically huge draw a battery has after a start.
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Re: Lithium Batteries?

Postby aerolithium » Fri Feb 01, 2013 10:21 am

If This topic is still alive about lithium batteries, you can contact me about it
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Re: Lithium Batteries?

Postby stede52 » Fri Feb 01, 2013 12:40 pm

Andy,
Could you explain to us how your batteries differ from other aircraft Lithium phosphate batteries on the market, what are the charging requirements and in reference to Danerazz comment, are there compatibility issues with some alternators? and if so, how can one tell if there is an issue?
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Re: Lithium Batteries?

Postby kenryan » Fri Feb 01, 2013 12:57 pm

Andy,

I would like to add to Steve's excellent questions by asking for a comment on how well these batteries perform in cold weather, say as low a +10F?
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Re: Lithium Batteries?

Postby aerolithium » Fri Feb 01, 2013 1:08 pm

ok
A - difference from other Lithium batts like shorai or Aerovoltz; my cranking amps and Ah capacity values are REAL #'s you can go by.
The other 2 tested less than advertised.
All use the same lifepo4 chemistry
B - they are drop in replacements for lead. charging output from regulator should be 14.0 to 14.4V.
A good ground connection is always needed, no special direct connection needed.
There is LESS draw from the alterrnator after starting because less charge was used from the lithium battery compared to a lead battery. so, shorter recharge time w less current after starting. never heard of any compatibility issues.
C - freezing temps will take 2 or 3 attempts, with each attempt stronger than before. This is opposite what a lead battery will do. For those regularly in freezing temps, I WILL soon have a self heating battery. push the button and 5 minutes later ... warm battery. = fast 1st start.
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Re: Lithium Batteries?

Postby GregArehart » Fri Feb 01, 2013 1:12 pm

I had a talk with a battery engineer the other day specifically about Li batteries. His comment was that "I can take any battery and make fire." His advice was that the Li-ion batteries are the biggest fire hazard, and (as noted previously in this thread) the real problem is runaway charging. Li-ion batteries produce oxygen during such an event and it is therefore difficult to extinguish a fire. Li-phosphate batteries are apparently much safer (do not produce oxygen) but can still cause a fire. He made a similar comment about lead-acid and NiCd batteries.

Just another data point for consideration.

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Re: Lithium Batteries?

Postby stede52 » Fri Feb 01, 2013 1:28 pm

Andy,
Thanks, one more question. I've heard the internal wiring can vary in these batteries and I've seen inside a few of them only to find some pretty light weight connection points and wiring which gives me some concerns when it comes to aircraft vibration. Have you done anything special with the internals of your batteries to make them more robust for aircraft applications?
Could you give us your actual web address?
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