facthunter Posted July 7, 2014 Share Posted July 7, 2014 Being able to find out the "real" facts in aviation matters is of the essence. Regarding "assisted" starting with a flat battery, and then expecting it to charge up in flight is foolish if you in any way may need the battery in flight. You normally assume the battery is serviceable ie in good condition and CHARGED. Some older aircraft had no electrical system at all, but there are more of the other as time passes. Management of your electrical loads and ability to go for say an hour on the battery if anything in the charge circuit fails is often necessary, and assumed to be available in the concept of some back up for fuel pumps, radio, possible engine restart and more, as we get more complex. An aeroplane can't just pull up on the side of the road and lift the bonnet, and hitch a ride. Nev Link to comment Share on other sites More sharing options...
2tonne Posted July 7, 2014 Share Posted July 7, 2014 It was a Lithium Ion battery (not Iron, people).The Brallie G9. Can't find anywhere that says it must be charged differently if the thing gets depleted... I wonder about this as a depleted battery being recharged within a car or motorcycle application after a bump/clutch start, would conceivably result in a vehicle fire, it would seem. From what I understand of lithium ion batteries (lipo) from using them in RC, they can become unstable when discharged rapidly (potentially leading to thermal runaway and fire), or when over discharged resulting in them becoming unstable. I believe that charging an over discharged lithium ion battery must be done carefully to avoid a battery catching on fire, and that it is not the usual charging process that is done to recover an over discharged battery. For RC purposes, I have always charged lipos in a fire proof bag on a non-combustible surface just to be sure. According to some information I found online for the Brallie G9, this 12v battery should never be discharged below 10 volts. Presumably it should be used with a low voltage cutoff to ensure it is not over discharged. Don't know if this was the case with this aircraft. 3 Link to comment Share on other sites More sharing options...
ExJourno Posted July 7, 2014 Share Posted July 7, 2014 Nev, Can't disagree. Contrary to the detail in the RAAus report, this bloke reckons there was sufficient charge to (probably) start it but he opted for the hand start given his engine is so easy to do that with and this would leave the battery power available for exactly what you talk about whilst it charged back up - plenty of power for avionics etc... didn't quite go the way he thought, obviously. I'd challenge anyone to fully detach themselves from their existing knowledge and consider what they'd have done in the exact same situation and with the specific knowledge this guy had. For a short local flight, not knowing the battery was only compatible with the system whilst fully charged, I would think a great many people would have thought nothing of letting the onboard system charge the battery back up to full. I may be wrong. One of the great benefits of globalised information and fast, wide-reaching communications systems (hooray for the Internet) is that a mishap can happen and the same day, people all over the place can know many details about it (admittedly, having to decipher what parts are credible). Anyone readying this thread, for example, will likely go away and do additional reading etc and avoid learning the same lesson for themselves... this particular incident, perhaps because it involved a friend, has cause me to go away and read quite a bit of detail for my own general knowledge and various comments have sparked me to go and search even more. 2Tonne, I'll ask... you've piqued my curiosity (and others', by the look of it) - and now I have a bit more to go and read about to aid me with future decisions. 1 Link to comment Share on other sites More sharing options...
facthunter Posted July 7, 2014 Share Posted July 7, 2014 Adam. Complexity seems to just keep coming while we generally expect someone else to sort out the difficulties for us. I infer NO criticism, of the individual, and you make your point well. I only found out similar problems with a non Pb battery in a modern motorcycle very recently and I like to think I am more aware than the average around these things. It would appear we need a temp sensor with some of this stuff.. or if they completely discharge they are a goner. I charge with a very low amperage charger that in theory could be left connected without damage. What got me concerned was the heat the battery developed even though the charge rate should not have permitted it. We can't all be experts in everything. Perhaps only employ trusted and tested stuff in aircraft. and keep it SIMPLE. Nev 2 Link to comment Share on other sites More sharing options...
turboplanner Posted July 7, 2014 Share Posted July 7, 2014 Mate, RAAus has determined the battery failed due to the charging system in the plane not being compatible with the battery in a deep charge situation - bearing in mind the owner did query prior to fitment, whether the charging system in his plane was suited to the G9 battery and was told it was "compatible".The bump start isn't the issue and hasn't been suggested to be. The issue is, apparently, damage to the battery causing it to fail due to being charged by the system in the plane whilst it was less than ideally charged... or in other words, whilst it was somewhat depleted. This may help: [GALLERY=media, 3272]Screen Shot 2014-07-07 At 2.32.09 Am by Adam Byatt posted Jul 7, 2014 at 2:34 AM[/GALLERY] Thanks for posting that Adam. Given that the screen shot relates to a forced landing, and a forced landing could easily be fatal given a couple of complications the RAA report is most disappointing. Lithium what? Where is the explanation? Where is the safety warning relating to batteries which should not be fitted into aircraft? The non-fatal incident reports are still way short of acceptable for use as learning tools. 1 Link to comment Share on other sites More sharing options...
Bob Llewellyn Posted July 7, 2014 Share Posted July 7, 2014 Thanks for posting that Adam.Given that the screen shot relates to a forced landing, and a forced landing could easily be fatal given a couple of complications the RAA report is most disappointing. Lithium what? Where is the explanation? Where is the safety warning relating to batteries which should not be fitted into aircraft? The non-fatal incident reports are still way short of acceptable for use as learning tools. It's a warning to us all that our "due diligence" better be a lot more suspicious, and perhaps even a bit more conservative. I'm pretty sure my membership fees aren't used to pay a set of technical experts... I thought RAAus's job was to allow us to fly at minimum expense and maximum personal responsibility. Engineering Services in CASA tried, and eventually failed, to provide engineering expertise in GA for this sort of issue; because the administrator's job is not consistent with maintaining up-to-date expertise on everything. It doesn't matter how good the people are, they can't do two jobs at once. I suggest we start a new thread to inform this community on the subject of battery options; there seems to be enough interest? 1 Link to comment Share on other sites More sharing options...
David Isaac Posted July 7, 2014 Share Posted July 7, 2014 Do a search ... There are many different types of Lithium batteries. An interesting one is the Lithium Iron (yes iron) Phosphate. LiFePo4. Can be charged continuously at 14.6 volts ... No boost, absorption, float type requirements. But read up on it. 1 Link to comment Share on other sites More sharing options...
turboplanner Posted July 7, 2014 Share Posted July 7, 2014 Interesting Bob that they have consistently disparaged and kept their distance from this site. Discussions and warnings about thermal runaway started here back in 2006. I understand your point, but good advice had been around for years just for the picking. 1 Link to comment Share on other sites More sharing options...
facthunter Posted July 7, 2014 Share Posted July 7, 2014 It is called the "TOO hard file" next to the "don't think about it and it will go away" memo, stored in the "what's in it for me?" division. Nev 2 1 Link to comment Share on other sites More sharing options...
Downunder Posted July 7, 2014 Share Posted July 7, 2014 Thanks for your reply Adam. So it's a battery that is marketed as an automotive replacement yet risks fire if over discharged and recharged using the existing automotive charging facility. That's a bit of a worry. Link to comment Share on other sites More sharing options...
rankamateur Posted July 7, 2014 Share Posted July 7, 2014 Do a search ... There are many different types of Lithium batteries. An interesting one is the Lithium Iron (yes iron) Phosphate. LiFePo4. Can be charged continuously at 14.6 volts ... No boost, absorption, float type requirements. But read up on it. These are going to be a game changer for stand alone solar power, but may be too new for anyone to really be able to trust in a plane for some time. Link to comment Share on other sites More sharing options...
Oscar Posted July 7, 2014 Share Posted July 7, 2014 It might help if someone ( David Isaac seems very qualified) could produce a matrix of Lithium battery characteristics ( cost, weight, charging risk, discharging risk, cranking power, charge system complexity etc). I believe LiFePo4 batteries are in general terms 'safe' in an aircraft environment - though I'll be encasing mine in a fire-resistant housing - if the charging system is reliable and they have a proper isolating switch. Link to comment Share on other sites More sharing options...
jetjr Posted July 7, 2014 Share Posted July 7, 2014 Well 8 or 9 Kg off a firewall would certainly be cause for a new weight and balance calculation in most aircraft !.....Maj..... Yes of course.......the point being? Be ironic if the w/b told you to put 8 or 9 kgs ballast back in the front .!!?? Yes but nice if it allows a kg or two removing from tail too, not too many ways to achieve 8-10 kg load increase under our rules Link to comment Share on other sites More sharing options...
Guest Maj Millard Posted July 7, 2014 Share Posted July 7, 2014 Yes of course.......the point being? Yes but nice if it allows a kg or two removing from tail too, not too many ways to achieve 8-10 kg load increase under our rules Point being a battery and its weight is often used or located to finally locate the CG within the aircraft's GC range. Substitute the standard battery with one considerably lighter and you now have an aircraft possibly outside of its CG range. Link to comment Share on other sites More sharing options...
Downunder Posted July 7, 2014 Share Posted July 7, 2014 http://www.recreationalflying.com/news/?page=2 Video: Mid-Continent's Lithium-Ion Ship's Batteries Lithium-ion batteries, which have three times the power of lead acid aircraft cells, are starting to find their way into new aircraft. Mid-Continent Instruments and Avionics has formed a new division called True Blue Power to serve this market. In this AVweb video, MCI's Todd Winter discusses the new battery products. Link to comment Share on other sites More sharing options...
Phil Perry Posted July 9, 2014 Share Posted July 9, 2014 Does "everyone"? Been flying since 1957, and have learned a few interesting facts vis a vis airborne electronics and battery / generator / alternator airborne power systems,. but in all that time nobody has ever told me that you can't charge a battery whilst it is being used,. . . . .So I must have missed that bit of info. . . . . Mind you,. . .willing to learn. . . . . I know that battery technology is advancing apace. . . . . . Phil Link to comment Share on other sites More sharing options...
fly_tornado Posted July 9, 2014 Author Share Posted July 9, 2014 Phil, lead acid batteries are very stable, part of the reason for their popularity. Lithium batteries are prone to catching fire when being charged. Its a trade off for the light weight and superior power. Link to comment Share on other sites More sharing options...
Phil Perry Posted July 9, 2014 Share Posted July 9, 2014 Point being a battery and its weight is often used or located to finally locate the CG within the aircraft's GC range.Substitute the standard battery with one considerably lighter and you now have an aircraft possibly outside of its CG range. Too Right Maj,. . . . when we built our X'Air kit, because we used the Rotax 'E' type gearbox with the starter motor IN FRONT of the engine, and retained the "Pull- starter" system at the rear of the engine, we had to position the battery well back along the fuselage tube, around half way thru the wing, to re balance the C of G. . . the battery is now in a ridiculous position if you ever need to jump start the thing with cables as this would require opening the top of the wing ( high strength velcro ) to get at the battery terminals, and then the hassle of retensioning the wing fabric again afterwards. . . .. . .! Fortnately, the battery is a simple SLA, and not afflicted with the Star Trek Lithium problem,. . . .which a few people are seemingly somewhat concerned about right now. . . . I'm watching the threads with interest as, when the initial teething prob;lems are resolved I think we may well have a very lightweight power system for superlight aircraft. I had a portable power drill explode last month, this had a lithium ION battery (18 volt, 1.3 AH ) attached to it. . . . the manufacturers are still looking at it, as it went off in the back of the vehicle, and had not been used nor charged for a few days, but the temp in the rear of the van was quite high on the day,. . .circa 27 Deg C . . . . dunno. . . . ? ? ? Phil Link to comment Share on other sites More sharing options...
Guest Andys@coffs Posted July 9, 2014 Share Posted July 9, 2014 .....Lithium batteries are prone to catching fire when being charged..... Perhaps better stated as Lead Acid battery charge requirements are broad and any old tractor charging system can work fine, Lithium charging systems require absolute characteristic matching with the pack they are charging and if there is any mismatch then damage through smoke release, possibly fire is a real possibility. Given the closeness of the match the charging systems are more complex and things like heat and age can unbalance these over time, Also if you use the lithium batterys outside their usage envelope same/same. Identifying whether you are in/out of the envelope requires good quality instrumentation and pilot/maintenance team responsibility/discipline Link to comment Share on other sites More sharing options...
Phil Perry Posted July 9, 2014 Share Posted July 9, 2014 It is a zenith.It was the battery. It will likely be flown off the paddock by tomorrow. The Chronicle has updated its story, no more mention of a crash. By "taxied" the witness was referring to the landing roll. What I consider a pathetic failure to properly fact check, by too many journalists, generally, shits me. The utterly irrelevant reference to the change in engine "pitch" is quite amusing. Has there been any reportage of aviation related matters that were actually reported correctly in the first instance? Like, even one? Hi Adam,. . . . We gave up on the local press years ago, after offering them ( as a Club) advice and background prior to printing a flight related story. . . . . They never bothered to call. The reason I Picked up on the "Engine Pitch" thing was that several witnesses of various aircraft incidents in past years have reported that the "pilot turned the engine power down a bit" as he went overhead, so he was obviously in trouble or going to crash. . . . ." after a very short while the accident investigators put this phenomenon down to "Doppler" effect. . . . .just another problem to add to those the investigators have to collate and sort out when dealing with innocent witnesses, and trying to satisfactorily interpret raw witness reports. Phil Link to comment Share on other sites More sharing options...
facthunter Posted July 10, 2014 Share Posted July 10, 2014 I've just worked it out. Li Po batteries are like women. Appear to offer all the answers but they only perform well if you know exactly how to treat them. Unsafe if you don't. Might even kill you. Nev 2 2 1 Link to comment Share on other sites More sharing options...
fly_tornado Posted July 10, 2014 Author Share Posted July 10, 2014 as opposed to lead batteries which never fail without warning 2 Link to comment Share on other sites More sharing options...
David Isaac Posted July 10, 2014 Share Posted July 10, 2014 as opposed to lead batteries which never fail without warning Really ...? Big generalisation there FT. Link to comment Share on other sites More sharing options...
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