Maybe Lithium batteries in gliders not quite such a good idea yet?

I like the idea of LiFePO4 batteries, but I'm not comfortable with the

commercial offerings, like those from Tenergy or K2. The data sheets

I've been able to obtain are incomplete compared to what I can get for

any of the comparable SLA batteries by manufacturers like PowerSonic,

Yuasa, Panasonic, and so on. The idea of paying 7 to 10 times as much

for a complex, poorly characterized battery is not enticing.



If I could buy a direct replacement 12 volt LiFePO4 battery from one the

major battery companies, with a full datasheet, then I'd think about it,

and would be much more comfortable suggesting them for other pilots.



--

Eric Greenwell - Washington State, USA (change ".netto" to ".us" to

email me)


I called K2 before I bought mine and they were very helpful answering my questions. The person I talked to said he has worked with other glider pilots to address their concerns too. From my experience, I think they would be happy to fill in the blanks.

They were expensive compared to SLA but for me, it was a good cost effective choice. I like all their advantages and, if they last for over 2000 charges like they say, I'll probably never need to buy another battery.

MK

On Friday, January 18, 2013 7:50:46 AM UTC-8, wrote:
When the batteries get submerged back there and short out. Then what?

Bruno - B4


The rising column of black smoke will assist in locating your glider underwater :c)


bumper

A lot of misinformation here. Read this instead:

http://www.luxresearchinc.com/news-a...eases/148.html

Keep in mind also that where there are problems is when recharging, not discharging, so use in gliders is not a problem. Also, most ELTs are shipped with lithium chemistry batteries now and have been used in aircraft in Canada since 2008 so a lot of pilots are already flying with them.

On Saturday, January 19, 2013 7:58:47 PM UTC-5, wrote:
A lot of misinformation here.

Duh, this is R.A.S...

Read this instead:
http://www.luxresearchinc.com/news-a...eases/148.html

And don't take it TOO seriously, unless you have personally
checked the batteries used and understand all the issues...

Keep in mind also that where there are problems is when recharging,
not discharging,

You think drawing excessive current will not harm the cells ?

so use in gliders is not a problem. Also, most ELTs are shipped
with lithium chemistry batteries now and have been used in aircraft
in Canada since 2008 so a lot of pilots are already flying with them.

Lets not compare apples and oranges.
Cells differ in many ways:
- electrolyte chemistry
- anode chemistry and construction
- cathode chemistry and construction
- general construction (thicknesses = damage tolerance and behavior)
- etc.
A cell design balances many factors for not just capacity,
but damage resistance, number of cycles, weight, cost,
temperature range, etc, etc, etc.

Without looking at the SPECIFIC cells used and the Thales battery
management system, it is very hard to tell what's wrong in 787.

Generalizing about anything that contains lithium is a bit silly...
Hope that helps,
Best Regards, Dave

PS: This flight crossed 800 hours in my (lithium-ion powered) Antares 20E:
http://www.onlinecontest.org/olc-2.0...l?dsId=2811077

On 1/19/2013 4:58 PM, wrote:
A lot of misinformation here. Read this instead:

http://www.luxresearchinc.com/news-a...eases/148.html

Keep in mind also that where there are problems is when recharging,
not discharging, so use in gliders is not a problem. Also, most ELTs
are shipped with lithium chemistry batteries now and have been used
in aircraft in Canada since 2008 so a lot of pilots are already
flying with them.

The ELT batteries are "primary" batteries, and are not rechargeable, so
I do not think they are relevant to our gliders. Since many pilots do
recharge batteries in their gliders, or in their homes, I think problems
when recharging are very relevant. Since we don't have much history with
Li-Fe batteries used in gliders or similar situations by people of
widely varying knowledge, and the drop-in units we can currently buy do
not seem to be well characterized, I am not keen to use them or
recommend them.

About a year ago, a group of us looked for batteries suitable for the
Perlan high-altitude glider. Because weight is critical to it's ability
to reach 90,000' and plenty of power is needed for all the systems, we
wanted the highest energy/kg we could safely get. Cost was a tertiary
issue. Eventually, we settled on the BA-5590, a primary lithium battery
used by the military for flights above about 60,000', and the
rechargeable BA-5390 for flights below 60,000'.

The two are physically identical, so they will fit in the same battery
box, but the primary battery has more energy per battery and per kg, but
at a much higher cost than the rechargeable battery. These batteries are
highly characterized and have plenty of history, so we believe they can
be trusted in the extreme conditions the Perlan will encounter.

We did try to get Li-Fe battery packs from Saft, but they weren't
interested in custom orders. Companies that would do custom orders
tended to be small assemblers of cells made in China by various
companies whose reliability we could not determine to our satisfaction.
I'm sure this situation will change in time, perhaps this year, but
we're not there yet, I think.

It was a definite disappointment we couldn't get the Saft batteries, as
they seemed almost ideal for gliders.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

On 1/20/2013 9:00 AM, Dave Nadler wrote:


Generalizing about anything that contains lithium is a bit silly...
Hope that helps,
Best Regards, Dave

PS: This flight crossed 800 hours in my (lithium-ion powered) Antares 20E:
http://www.onlinecontest.org/olc-2.0...l?dsId=2811077

You're not flying enough, Dave! The batteries will last longer than you
do, if you don't pick up the pace .. :^)

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

On Sunday, January 20, 2013 1:44:23 PM UTC-5, Eric Greenwell wrote:
It was a definite disappointment we couldn't get the Saft batteries,

Because of the hazards associated with battery misuse, SAFT will
*only* sell to qualified organizations. Its expensive for them
to qualify an organization and application, so small custom
lots are out of the question...

as they seemed almost ideal for gliders.

Yes, SAFT make some cells that are ideal, hence use in Antares...

Best Regards, Dave

My company has 787's on order, but they won't be delivered until 2014 (if then) and I'm glad I'm not having to fly the thing while this entire episode gets sorted out.
An inflight fire is one of the, if not the worst things that could happen to you. I had a cockpit fire breakout behind the engineer's panel after landing in an E-3A back in the 80's that was electrically generated and it spread with amazing speed and put out an incredible amount of smoke and fumes in a very short time. Fortunately, killing all power to the aircraft pretty much stopped the conflagration..but had it happened 10 minutes earlier while we were in hard IFR on downwind...

BTW, if you're wondering where you've heard the company named "Thales" that's mentioned in this thread and the article below, they gained prominence in the Air France 447 loss over the Atlantic some years back when the pitot tubes they manufactured iced up and were cited as a factor in that accident..

Rob
ZAP


http://www.flightglobal.com/news/art...ritory-381148/

ANALYSIS: Grounding order moves 787 into uncharted territory

By: Stephen Trimble Washington DC

02:29 17 Jan 2013

Source:

A grounding order by the US Federal Aviation Administration (FAA) moves the Boeing 787 programme into territory uncharted for a modern airliner as long as a recently discovered "battery fire risk" remains unsolved.

The order by the FAA effectively grounds six 787s operated by United Airlines and aligns the US regulator with two Japanese airlines - All Nippon Airways and Japan Airlines - that ceased 787 operations earlier on 15 January. But the action also forces five other airlines operating the 787 to reconsider the aircraft's safety for an undetermined period.

Boeing must demonstrate that it has eliminated any risk of a battery-ignited fire before the grounding will be lifted. Jim McNerney, Boeing's chief executive, says the entire resources of the company will be put at the disposal of the effort to discover the source of the battery fire risk and to correct it.

Engineering resources, meanwhile, could be diverted from other strategic efforts in 2013, such as doubling the 787's monthly production rate, completing the assembly and launch flight testing of the 290-seat 787-9 and launching the potential 320-seat 787-10.

The grounding may not have an immediate impact on aircraft valuations, as no market exists for second-hand 787-8s yet, with only 51 of the type delivered.

But the public and regulatory safety concerns growing around the programme could make it harder for some airlines and lessors to obtain financing, says Les Weal, head of valuations for the Flightglobal Ascend consultancy.

"If you were asked to finance one today, you may have to pass on the opportunity," says Weal, explaining that such financiers have no shortage of requests bearing less risk than the 787. In the hours leading up to the FAA grounding order, Flightglobal Ascend still assigned a $110 million valuation for a new 787-8 built in 2013.

On top of the programme's financial concerns, Boeing may also need to restore confidence in the 787's entire electrical architecture. It was designed as a technological leap forward, reducing fuel consumption by several percentage points, and using electricity to replace parasitic bleed-air to power onboard systems and cabin pressurisation.

But the power system with nearly 1.5MW (2,010hp) of capacity has been a source of constant headaches barely 15 months into service. A suspected batch of poorly-built circuit boards are likely to have caused a series of glitches on power distribution panels of several aircraft in December 2012, forcing United and Qatar Airways to briefly ground some aircraft to perform repairs.

Far more worrisome, however, are the newly-realised risks of fire posed by the two lithium-ion polymer batteries, a powerful chemistry is described as a "first" in commercial aviation on the 787. Boeing selected a lithium-ion-based battery proposed by electrical power conversion system supplier Thales, which packaged an industrial-grade battery designed by Japanese firm GS Yuasa and a battery charger unit made by Securaplane, based in Tucson, Arizona.

Industry and government regulators were aware of the risks of potential safety hazards posed by battery chemistries based on lithium-ion.

In 2006, Securaplane's administration building "burned to the ground" because of a botched laboratory test involving a GS Yuasa battery designed for the 787. In 2007, the FAA imposed a set of special conditions for Boeing to prove the safety of lithium-ion batteries before the agency would grant airworthiness certification for the new aircraft.

The certification tests appeared to show that Boeing had passed the FAA's test. The lithium-ion battery allowed Boeing to start the auxiliary power unit with a device half the size of comparable nickel-cadmium or lead acid batteries used in previous aircraft designs.

Last week, Michael Sinnett, the 787's chief project engineer, said lithium-ion is not the only acceptable solution, but it was still the best option for the 787.

Any future design must show that the battery is safe, even if something fails and heat builds up to dangerous levels, says Hans Weber, head of the Tecom aviation consultancy.

Such a design must ensure that a fire is contained and is quickly extinguished by being deprived of oxygen, he says. Moreover, most, if not all, of the smoke generated by the flames must be vented outboard, rather than be allowed to circulate inside the pressurised cabin, he says.

Speaking hours before the FAA imposed by the grounding order, Weber said the public and regulatory response to the ANA and JAL battery incidents had been surprising.

"It's been driven by emotion, which is understandable," he says. "The emotion generated by a fire on board is high. That's one of the scariest things to contemplate."

On Sunday, January 20, 2013 1:59:45 PM UTC-5, RAS56 wrote:
.... In 2006, Securaplane's administration building "burned to the ground"
because of a botched laboratory test involving a GS Yuasa battery designed
for the 787. In 2007, the FAA imposed a set of special conditions for Boeing
to prove the safety of lithium-ion batteries before the agency would grant
airworthiness certification for the new aircraft.

http://www.reuters.com/article/2013/...90J06I20130120

On 1/20/2013 10:51 AM, Dave Nadler wrote:
On Sunday, January 20, 2013 1:44:23 PM UTC-5, Eric Greenwell wrote:
It was a definite disappointment we couldn't get the Saft
batteries,

Because of the hazards associated with battery misuse, SAFT will
*only* sell to qualified organizations. Its expensive for them to
qualify an organization and application, so small custom lots are out
of the question...

as they seemed almost ideal for gliders.

Yes, SAFT make some cells that are ideal, hence use in Antares...

Hmm, maybe the Perlan Project could buy some "spare" Saft cells from
Antares, in anticipation of ordering an entire glider ... eventually.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)