On Thursday, March 22, 2018 at 10:04:02 PM UTC-4, jfitch wrote:
On Thursday, March 22, 2018 at 3:37:31 PM UTC-7, Andrzej Kobus wrote:
On Thursday, March 22, 2018 at 1:09:13 PM UTC-4, jfitch wrote:
On Wednesday, March 21, 2018 at 5:00:32 PM UTC-7, Andrzej Kobus wrote:
On Wednesday, March 21, 2018 at 7:18:52 PM UTC-4, jfitch wrote:
On Wednesday, March 21, 2018 at 12:12:31 PM UTC-7, Tango Eight wrote:
On Wednesday, March 21, 2018 at 2:15:26 PM UTC-4, jfitch wrote:
On Wednesday, March 21, 2018 at 10:22:48 AM UTC-7, Charlie M. (UH & 002 owner/pilot) wrote:
While I usually don't disagree with you, if you READ what Tango8 posted, he is saying the same thing as you.
"Lithium in the name does make it the same", as I read it.

Your thoughts?!

Yes, I am going from early (late '70's NiCads to more modern LiFe or LiOn/LiPo) rechargeables including LA of various flavors.

I have a bunch of cash tied up in chargers for various battery chemistries, mostly in RC use, but also for my main income.

Hey, hey find an issue with my read of Tango8's post, I am willing to learn, but I believe you read it wrong.

I don't believe it is dangerous to refer to Lithium Ion batteries as Lithium Ion batteries. But in T8s post he said it was, and further said '"LiIon" vs "LiPo" vs "LFP"' which implies that Lithium Ion batteries are a type of Lithium Ion batteries. The semantics matter. Had he quoted my post in context (the complete sentence was "If it has lithium in it, it is a Lithium Ion battery, but beyond that there are big differences in chemistry and mechanical construction.") perhaps he would have not thought what I said dangerous. You cannot charge a LiIon battery differently than an LFP, because an LFP IS a LiIon battery. LiIon includes all the different chemistries but the members of that group differ in their associated charge requirements.

It is much better to use language precisely when the result of a misunderstanding can be an explosion and fire. If you specify an LFP charger you should get want you want. If you specify a LiIon charger you have no idea what you are going to get.

Jon, you're clearly unfamiliar with the terminology as it is used out in the real world. There are many (millions) multi-mode chargers out there that use the terms as I have used them, "LiIon, LiPo, LFP". Semantics matter? Sure. Safety based on correctly matching charging cycles to chemistry matters more.

Here's a link to the instructions for a commercial charger that illustrates what I am talking about. They use the terms LiIo, and LiFe instead of LiIon and LFP.

http://www.ircha.org/sites/default/f...ntam%20BC6.pdf

I am well aware of the loose and incorrect usage of terms, and it is what I am arguing against as potentially dangerous. As I said in my second post in this thread, "unfortunately there is confusion". What exactly is the voltage and chemistry of a LiIo, or LiIon, or Lithium battery? In the real world, Google "lithium ion battery" will correctly return hits on all types, not just lithium polymer, with recommended charging voltage of between 3.2 and several hundred volts. Even in the last few of posts we have the conflation of several chemistries. The news media is horribly guilty of this, from them we know that lithium batteries cause cars and aircraft to catch fire and burn, and hoverboards to self immolate. I have been told on this very forum that lithium ion batteries should not be used in gliders because they cause Boeing 787s and Chevy Volts and Samsung S7s to burn - never mind that those batteries are quite different than the ones we use.

If I have a charger than says "LiIo" or "lithium" charger on it, that tells me little or nothing about what battery I can charge with it. This is my point. "Correctly matching charing cycles to chemistry" can only be done if the specific chemistry or voltages required are stated. "Lithium ion" is the term used for the collection of chemistries using lithium anodes or cathodes. If that is not the correct term, then what is? And why is it "dangerous" to use the correct term? And if speaking in a context where the specific chemistry dangerously matters, shouldn't the specific term be used, rather than the general?

John, I am sorry, but aren't you the one who uses unapproved, for starting, LiFePo4 batteries in your ASH-26E for engine starting? I am surprised you seem to lecture others while you do questionable things yourself, just saying.

Andrzej, the Schleicher maintenance manual (which specifies SLA batteries for both engine AND avionics) was written in 1995, and is not likely to consider a battery technology invented in 1996. Anyone flying an ASW 27 or 29 should similarly not use an LFP battery for avionics as they are not an approved type. Yet nearly every glider supply outlet sells them for this purpose, and I note that Schleicher ships LFP batteries for both start and avionics in many of their current gliders.

I'm not lecturing (or even recommending) people to use or not use anything. I educated myself on what was required and acted accordingly based on facts, not questions. I AM asking that they use precise language, where precise language is important. Schleicher does not say "use a lead battery", rather they say "use a maintenance free lead-dry-gel battery" - because installing a flooded lead acid battery on its side near your butt is a bad idea. Even then they are imprecise - the battery they call out is an AGM, not a gel and these have different charge requirements. The terminology matters.

John, the battery you are using was not designed for starting purposes. The CTC LFP128198 is only rated for 100 Amps for 30 sec, not as you stated in another thread at 160 Amps for 30 sec. 160 Amp is the rating of the protection circuit with is not enough in this application (http://sepbatteries..com/media/add_info/LFP128198.pdf). You are simply operating this battery at very thin safety margins. I am surprised that this does not bother you. A more appropriate solution would be EarthX battery specifically build for experimental aircraft as an engine starting battery, http://earthxbatteries..com/product-...ental-aircraft
Yes, it is very expensive but your life is priceless, or a better solution; or better yet the Odyssey PC680 Battery

Andrzej, I appreciate your concern for me. I did misstate the spec, it is 100 amps for 30 seconds. (In a conversation with the designer, he said 150 amps for several seconds). Fortunately that is more than adequate to start the engine (I have measured the starting current, typically 80 amps for 3 seconds, and it has been routinely starting my engine for 3 years now). CTC in their marketing literature has stated that the battery is designed for engine start use. But perhaps the biggest problem I have is the characterization that this is a safety issue. It is not a safety issue. In the worst case, the battery will go into overcurrent protection and disconnect. If you are flying a motorglider in any situation where a dead starting battery is a safety issue, you need to review your flying practices. Even the ASH flight manual warns against this in section 4.5.1, "One must always be prepared for the possibility that the power plant will fail to deliver the hoped for propulsion." I love that sentence.

Second, you apparently have not looked into the specifications of the SLA battery Schleicher specifies. It is the Yuasa 18-12, the data sheet spec's a maximum discharge of 112 amps. Are they "simply operating this battery at very thin safety margins"? It is much more likely to reach that maximum than the CTC, because the internal resistance is much higher and the starter voltage lower. It is not advertised or spec'd for engine start use. The Odyssey PC680 is a TPT starved electrolyte battery and does not meet Schleicher's specification of a "lead-dry-gel battery". These batteries ARE a safety issue as they have no internal overcurrent protection and will literally melt down in a fault. There is no fault protection in the starting circuit of an ASH26.

The earthX battery does not fit in the hole. There are other LFP motorcycle "starter" batteries that will, but most do not have the same true AH capacity.

You may use whatever battery you like, but don't worry about me - I'm perfectly safe.

John, sorry to disappoint you, Schleicher does not install "lead-dry-gel batteries" in their gliders. They install AGM batteries with maximum discharge current for 5 seconds of 330 Amps. Try that with your battery. Relying on Chinese mass produced circuits for your safety is not something that I would be willing to do at these current levels. Odyssey PC680 is an AGM battery, which is the same type as the one installed by Schleicher.