KRnetters, True confessions time... About seven years ago I flew N191PZ from Seattle to San Diego with an overnight stop at Van Nuys (KVNY) airport in LA. I started up at Van Nuys, taxied out and took off per normal. About 20 minutes into the flight my transponder was reported to be intermittent, right over LA basin. Another 10 minutes went by as I checked everything in the cockpit... except the alternator switch, which had been off the entire time. I do not like feeling nor looking like an idiot, but I sure was one that day. That said, the battery started the plane, ran my radio, transponder, and EFIS displays for 30 minutes airborne and was still pumping out enough juice to fire the engine. The transponder would not hack the lower voltage (Old NARCO AT-50A box = VERY HIGH power requirements), but the rest of the plane was doing just fine. It is up to each pilot/builder to decide whether or not they have sufficient (battery) power on board, but I am proof positive the Corvair motor with a single battery will save your hash even when you are being a moron for 30+ minutes. I am just finishing the build on a Corvair-powered Saberwing and will be going with a single gel-cell battery based on experience. Your mileage may vary. iMs, Zip -----Original Message----- From: "Flesner via KRnet" <krnet@list.krnet.org> Sent: Saturday, August 11, 2018 4:24pm To: "Stef den Boer via KRnet" <krnet@list.krnet.org> Cc: "Flesner" <fles...@frontier.com> Subject: Re: KR> Backup battery
On 8/11/2018 5:41 PM, Stef den Boer via KRnet wrote: > Hi, > I am using also 2 batteries. Both are 7 amps but li-ion. Strong enough for my > engine. One is to start the engine with awg 8 and one as a backup for the > fuel pump and ignition with awg 12. One batterie gives me 20 min. So if I > have a alt failure I have at least 40 min flight time left. > Stef > > +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Stef, Don't count on getting the full reserve out of the batteries as the voltage will drop as the capacity is use. The lower voltage may not be sufficient for the electronic ignition. Li-ion may hold a better voltage than lead acid but take a look at Li-ph (lithium phosphate?) for safety reasons, much more stable. Someone more educated on the subject might offer better advise. Larry Flesner _______________________________________________ Search the KRnet Archives at https://www.mail-archive.com/krnet@list.krnet.org/. Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options. To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org _______________________________________________ Search the KRnet Archives at https://www.mail-archive.com/krnet@list.krnet.org/. Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options. To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org
