X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 10 [X] Return-Path: Received: from [208.97.132.83] (HELO spaceymail-a1.g.dreamhost.com) by logan.com (CommuniGate Pro SMTP 5.1.6) with ESMTP id 1820158 for flyrotary@lancaironline.net; Tue, 06 Feb 2007 20:22:05 -0500 Received-SPF: none receiver=logan.com; client-ip=208.97.132.83; envelope-from=billdube@killacycle.com Received: from mungo.killacycle.com (mungo.al.noaa.gov [140.172.241.126]) by spaceymail-a1.g.dreamhost.com (Postfix) with ESMTP id 010FB194F0F for ; Tue, 6 Feb 2007 17:21:16 -0800 (PST) Message-Id: <7.0.1.0.0.20070206180050.01e2a9f0@killacycle.com> X-Mailer: QUALCOMM Windows Eudora Version 7.0.1.0 Date: Tue, 06 Feb 2007 18:12:03 -0700 To: "Rotary motors in aircraft" From: Bill Dube Subject: Re: [FlyRotary] Re: Finally built - 3.7 lb, 600 cranking amp, 11.5 A-hr battery In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed You need to isolate it from over and under voltage as much as you would your present sealed lead-acid battery. I would suggest a buzzer connected to a door switch to warn you that you have left the master on. You should also have a warning light on the panel for over and under voltage. You should have these already. Keep in mind that this battery will withstand over and under voltage. It just "wounds" it much like such mistreatment "wounds" your present sealed lead-acid battery. This battery will take the abuse without creating an additional hazard. Other, less safe, types of Li-Ion batteries will do very bad things (like burst into flames) if you subject them to abuse. You wouldn't want to use anything other than a warning system for over and under voltage. This would cause a hazard greater than letting the battery "take the abuse". There is no danger in abusing the battery other than reducing its capacity for later use. To give you an idea of how tough these batteries are, we routinely heat these up to 100 C (212 F) in the bike. We routinely draw 50% more than their rated current. We routinely go below the minimum voltage (briefly.) We have accidentally over charged some of these cells. Yet, despite this abuse, we have never had to replace a single one of the 880 cells in the bike. These are not the delicate Li-Ion cells that they put in your laptop or cellphone. Bill Dube' At 02:54 PM 2/6/2007, you wrote: >Bill can you isolate it from low voltage and over charging? >George ( down under) > >>We figured that most folks would want a battery that had the >>cranking amps to easily spin the starter and would not care much >>about the a-hrs. >> >>The cost is directly proportional to the amp-hrs. If we were to go >>to 16 amp-hrs (it's easy to do) the cost would go up to about $850. >>The cranking amps would also go up in proportion too. Figure about >>$1 per cranking amp, and about $50 per amp-hr and you won't be far >>off. The steps are 2.3 a-hr and 120 cranking amp increments. You pick. >> >>This battery REALLY spins the starter in my GMC van. When I turn on >>the key in the morning, the battery voltage is typically 13.4 volts >>(instead of 12.8 volts.) >> >>Anyone in the Denver area that flies daily interested in flight >>testing one of these? You would get to keep the battery and write >>anything you want about it (good or bad) as long as it was >>truthful. You would have to inspect it before and after each flight >>including noting the voltage and the BMS indicator light status. >>You must sign the usual liability waiver we are all now accustomed >>to of course. :-) >> >>I'd flight test it myself, but I'm still building the wings on my RV-7. ;-) >> >>Bill Dube' >> >>bike@KillaCycle.com >> >>At 10:05 AM 2/6/2007, you wrote: >>>That is indeed impressive, Bill. Weights about 10 lbs less than >>>the Odyssey PC680, equivalent cranking amps, bit more voltage, so >>>a bit better power, only 5 A-hr less than Odyssey. So looks like >>>you could double the weight 7.4 lbs and have MORE A-Hr and still >>>1/2 the weight of the Odyssey. >>> >>>If I were to make a suggestion, it would be to look at the >>>marketing advantage of having more A-hr than the Odyssey at 1/2 >>>the weight (If it scales that way). The aircraft market and >>>racers are probably two areas that would be interested in that >>>kind of weight savings at that price. Just my 0.02 >>> >>> >>>Ed >>>----- Original Message ----- From: "Bill Dube" >>>To: "Rotary motors in aircraft" >>>Sent: Tuesday, February 06, 2007 11:21 AM >>>Subject: [FlyRotary] Finally built - 3.7 lb, 600 cranking amp, >>>11.5 A-hr battery >>> >>> >>>>Well, I said I was going to do it and we finally got the prototype built. >>>> >>>>We just built a 600 cranking amp, 11.5 A-hr, battery that weighs >>>>just 3.7 pounds. I've been testing it in my GMC van for the past >>>>week here in the Denver Winter. It snaps the van right over every >>>>morning without a problem. The van cranks faster than it did with >>>>the standard lead-acid battery. >>>> >>>>It is smaller than the Odyssey 680 so it fit in the same battery >>>>box with a couple of foam blocks for spacers. >>>>The battery has four status LEDs that tell you the cell balancing >>>>electronics are working OK. We are using A123 Systems M1 cells >>>>with our own custom battery management electronics. The A123 >>>>Systems cells are proven to be the safest Li-Ion cells on the >>>>market. No problems with fires (like laptop cells) because the >>>>chemistry they use is completely different. >>>> >>>>The battery can be damaged by running it completely flat (like >>>>leaving the master on) and holding the battery below 8 volts for >>>>a long time. It can also be damaged by charging it over 15.0 >>>>volts. It will likely still function after such abuse, but it >>>>won't be nearly as good as it was originally. If you don't abuse >>>>it, it should last you for many years. >>>> >>>>I think we will be in production in about a month, maybe two. >>>> >>>>Specs: >>>> >>>>3.7 lbs >>>>600 cranking amps >>>>11.5 amp-hr >>>>Approximate maximum dimensions: 3" wide, 5" long, 7" tall >>>>(including terminals) >>>>Charging voltage = 13.8 to 15.0 volts (anywhere in this range is OK) >>>>Nominal voltage = 13.2 volts (Just a touch higher than your >>>>typical lead-acid, so it spins the starter a touch faster.) >>>>Cell cycle life rated at 2000 cycles (80% DOD, 90% capacity >>>>remaining) 10,000 cycles (80% DOD with 50% capacity remaining) @25 C >>>>Cell specs: >>>>http://www.a123systems.com/html/products/ANR26650M1specs.pdf >>>>Maintenance free >>>>No heavy metals (iron-phosphate type cells) >>>> >>>>At this time, we estimate the retail price will be $595. (Yeah, I >>>>know this is not cheap, but this is the state-of-the-art battery >>>>technology so the parts to make it are not cheap.) >>>> >>>>Here is a picture of the prototype. We have it in a clear Lexan >>>>case so we can keep an eye on it. The production battery will >>>>have a smaller opaque case with a clear top lid (terminal end.) >>>>http://www.killacycle.com/photos/aircraft-battery/Prototype1InVan.JPG >>>> >>>> >>>>We have been racing these cells in the KillaCycle for about a >>>>year, so we know _all_ about them. >>>>http://www.KillaCycle.com (Be sure to >>>>watch the movie clip.) >>>> >>>> >>>>Bill Dube' >>>>bike@KillaCycle.com >>>> >>>> >>>> >>>>-- >>>>Homepage: http://www.flyrotary.com/ >>>>Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ >>> >>> >>>-- >>>Homepage: http://www.flyrotary.com/ >>>Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ >> >> >>-- >>Homepage: http://www.flyrotary.com/ >>Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ > > >-- >Homepage: http://www.flyrotary.com/ >Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/