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

I have been very actively looking for the perfect "new technology" battery solution for my glider for a few years. I have been looking to fill two battery trays in my 27B fitted for the standard 6' x 2.6" x 3.7" 12 volt 9ah lead batteries with lighter and higher amp hour batteries. There has been lots of discussion around various solutions here on the web over the last few years. Many glider pilots have already switched to one "new tech" battery or another and report good results.

So Boeing is not dumb. I highly doubt they are roughly handing their lithium batteries and I am sure their wiring is better than most glider wiring patch jobs! But here they are having problems with batteries smoking and even possibly worse while in use. I sure don't want to have that problem when I am at 17,999 ft behind my head. Are the "new age" batteries being used by gliders safer than those at Boeing? I am not trying to make a statement with this thread or questions. I am still moving down the path of switching out batteries before the season and want to make the correct/safe decision. Why are they having problems and we are not so far?

BTW, my panel is full of fun electronic toys and if I ever want to do a 10+ hour flight, 2 9ah lead batteries will be hard pressed to get the job done..

Oh yeah, sign up for the Nephi, Utah Camp August 7-11

Thanks,
Bruno - B4

On Thursday, January 17, 2013 1:46:15 PM UTC-5, wrote:
I have been very actively looking for the perfect "new technology" battery solution for my glider for a few years. I have been looking to fill two battery trays in my 27B fitted for the standard 6' x 2.6" x 3.7" 12 volt 9ah lead batteries with lighter and higher amp hour batteries. There has been lots of discussion around various solutions here on the web over the last few years. Many glider pilots have already switched to one "new tech" battery or another and report good results.



So Boeing is not dumb. I highly doubt they are roughly handing their lithium batteries and I am sure their wiring is better than most glider wiring patch jobs! But here they are having problems with batteries smoking and even possibly worse while in use. I sure don't want to have that problem when I am at 17,999 ft behind my head. Are the "new age" batteries being used by gliders safer than those at Boeing? I am not trying to make a statement with this thread or questions. I am still moving down the path of switching out batteries before the season and want to make the correct/safe decision. Why are they having problems and we are not so far?



BTW, my panel is full of fun electronic toys and if I ever want to do a 10+ hour flight, 2 9ah lead batteries will be hard pressed to get the job done.



Oh yeah, sign up for the Nephi, Utah Camp August 7-11



Thanks,

Bruno - B4

The A123 (Nanophosphate-Lithium Iron Phosphate) batteries are regarded as being extremely tolerant to abuse. From my RC plane flying you generally won't have any issue if the batteries are kept at a moderate temp and they aren't overcharged. Boeing's issue is believed to be overheating, which is pretty reasonable given the load that they have.

JP

On Thursday, January 17, 2013 1:46:15 PM UTC-5, wrote:
I have been very actively looking for the perfect "new technology" battery solution for my glider for a few years. I have been looking to fill two battery trays in my 27B fitted for the standard 6' x 2.6" x 3.7" 12 volt 9ah lead batteries with lighter and higher amp hour batteries. There has been lots of discussion around various solutions here on the web over the last few years. Many glider pilots have already switched to one "new tech" battery or another and report good results.



So Boeing is not dumb. I highly doubt they are roughly handing their lithium batteries and I am sure their wiring is better than most glider wiring patch jobs! But here they are having problems with batteries smoking and even possibly worse while in use. I sure don't want to have that problem when I am at 17,999 ft behind my head. Are the "new age" batteries being used by gliders safer than those at Boeing? I am not trying to make a statement with this thread or questions. I am still moving down the path of switching out batteries before the season and want to make the correct/safe decision. Why are they having problems and we are not so far?



BTW, my panel is full of fun electronic toys and if I ever want to do a 10+ hour flight, 2 9ah lead batteries will be hard pressed to get the job done.



Oh yeah, sign up for the Nephi, Utah Camp August 7-11



Thanks,

Bruno - B4

Boeing is said (by a Boeing engineer) to be using LiPo batteries. Any RC guy would tell you that's crazy. So I wonder if there is more to the story or if the info is just wrong. Lithium iron phosphate (LiFePO4) is what's being used successfully as a SLA replacement in sailplanes. They have a pretty good track record so far as I know (similar to PB SLA -- the big hazard is accidental short circuit, not auto ignition. As long as the internal construction is robust and there is an external fuse at the battery, they should be fine). I plan on replacing my Pb SLA batteries with LiFePO4 when they warrant it. The lithium batteries are still improving in performance and cost.

T8

Light weight and high energy density requires reactive materials for batteries.

I worked in a lab some years ago where one division was developing a sodium/sulfur battery. Light weight and high energy density made this combination appealing, although the design operated at high temperatures with both elements molten. It did not go well! The natural state of the combination appeared to be fire, with the special benefit for firefighters of dealing with burning molten sodium.

Lithium isn't all that far from sodium on the periodic table! I'll stick with lead for now, thanks!

Mike

Here is an article regarding LiFePO4 batteries from Soaring Cafe. It's a couple years old and I didn't see anything else more recent. However, pretty informative.

http://soaringcafe.com/2011/01/new-t...der-batteries/




Boeing is said (by a Boeing engineer) to be using LiPo batteries. Any RC guy would tell you that's crazy. So I wonder if there is more to the story or if the info is just wrong. Lithium iron phosphate (LiFePO4) is what's being used successfully as a SLA replacement in sailplanes. They have a pretty good track record so far as I know (similar to PB SLA -- the big hazard is accidental short circuit, not auto ignition. As long as the internal construction is robust and there is an external fuse at the battery, they should be fine). I plan on replacing my Pb SLA batteries with LiFePO4 when they warrant it. The lithium batteries are still improving in performance and cost.



T8

Can I briefly ask the naive question: What is wrong with a few lead
batteries? Weight? Installing/removing? The circuitry?

On Thu, 17 Jan 2013 20:26:43 +0000, Roel Baardman wrote:

Can I briefly ask the naive question: What is wrong with a few lead
batteries? Weight? Installing/removing? The circuitry?

Space and weight, particularly if you fly an older glider and like to put
electronic toys in your cockpit.

The problems with anything much more exotic than sealed lead-acid gel
cells (SLA) are cost and the need for more intelligent (and expensive)
chargers.

That said, IMO you're cheating yourself if you don't use a charger that
can detect full charge, and hence won't over-charge the battery, and can
automatically cycle batteries and measure the battery capacity. Same goes
for buying cheap batteries: I like Yuasa SLAs, which reliably give me 3-4
years flying.

I cycle and test my batteries each winter and log the measured capacity
of each battery: this makes it really easy to see when one should be
replaced.

I use Sunpower multi-stage mains chargers for my SLA glider batteries and
never leave them partially charged: the batteries are put on charge as
soon as I get home from flying.

I have a fairly basic Pro-Peak Prodigy multi-chemistry charger (lead-
acid, NiCd, NiMH, Li-ion, Li-poly) that I use for testing the SLAs and
for charging and testing the other batteries I use in models, cameras,
etc. Pro-Peak and similar chargers are sold wherever you by RC and
electric model aircraft gear.

I also have a Vencon charger/cycler, but this is a beast of a very
different stripe: it is controlled and programmed by a management program
running on a Windows PC. This kit is not cheap, but if you're serious
about battery monitoring or have a lot of batteries that are used for
critical tasks its the one to use.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Thursday, January 17, 2013 12:26:43 PM UTC-8, Roel Baardman wrote:
Can I briefly ask the naive question: What is wrong with a few lead

batteries? Weight? Installing/removing? The circuitry?

I've been running A123 cell packs for several years now. I built the packs myself in the days before you could just buy them. I also did some destructive testing to satisfy myself that the risk was acceptable.

There are several advantages other than the weight savings:

(1) The have a very flat voltage profile as they discharge.

(2) Their capacity is relatively insensitive to ambient temperature. So for long wave flights they are ideal, you get well over 80% of the rated capacity down to -10 °C IIRC.

(3) They don't have issues with "memory"

Chris
42DJ

On Thursday, January 17, 2013 1:26:43 PM UTC-7, Roel Baardman wrote:
Can I briefly ask the naive question: What is wrong with a few lead

batteries? Weight? Installing/removing? The circuitry?

The problem is I have limited battery tray space and need higher amp hours in the same tray than lead acid can provide. Again, this is to be able to fly 10+ hours on a wave day later this year.

Bruno - B4

Bruno,

I have an ASW-27 also. I use 2 tenenergy 10ah LiFePo4 batteries... Kickass

They have special cicuitry that allows them to be charged via regular 12V SLA charger (so if you forget your charger on a trip...WalMart!)

I run a Cambridge 302, ClearNav, Radio (of course) and PowerFlarm. I have yet to have a single battery drain to the point of switching. That includes an 8 hour long out and return this past year.

Also... The other folks here are right... LiPo are the dangerous battery. LiFePo4 are quite safe. The chance of an oxygen pocket being formed are damn near zero.

Terry