Pietenpol-List: batteries
Posted: Thu Dec 12, 2002 8:14 am
Original Posted By: "Richard Navratril"
Dick Navratil writes->With this weight I might consider installing a 35 amp battery in the>nose (35 lb.) for a transponder and radio.Do you want to consider some weight savings? Here's a snip from Mark Langford's KR website that relates his investigation on batteries. Much of what Mark was investigating relates to the requirement for cold cranking amps for a starter, so keep that in mind if you don't need starter juice:====================================I'm always looking to save weight, and was quite intesrested in the Black Panther batteries in the Wicks catalog. They list one that has 600 CCA (cold cranking amps) that I later discovered is a 16Ah (at 10 hours) battery, for $113. I looked at Gills, Bells, Interstates, etc, and finally came full circle to the actual manufacturer of the Black Panther, which is Hawker Energy Products. The standard aircraft batteries are typically 25 or 35 Ah. The AGM technology used in the Hawker Genesis batteries makes them very reliable and with an amazingly high CCA value for cranking things like large 6 cylinder Corvair engines. They are also permanently sealed (by definition) and can be mounted in any orientation.My KR2S electrical system is going to be very current miserly. My radio and transponder are Terra (less than 2A combined), strobes are Kuntzlemann (less than 2A draw), ignition is coil and points (1A per 1000 rpm, according to William) totaling 3A at cruise, and my nav lights are super bright LEDs (Stefan Belatchev's idea) that draw less than .1A. All of this can be turned off so that only the engine's coil and fuel pump are running, which totals 3.7 amps. My ignition switch will control ignition coil and fuel pump without a breaker inline (if either quits, you're going down anyway), but all other electrical items will be separate and will have breaker/switches. The G12V16EP battery that I chose will run this "minimum load" for 4 hours! And if my Corvair runs anything like the rest of my cars, it'll start in 1 or 2 seconds, mininizing starting drain.My EIS (Engine Information System) has programmable alarms, and the voltage trigger level can be set to something like 13 volts so that if my alternator quits charging, the EIS will immediately notify me and I'll have something like 2 hours to find a landing spot even without bothering to switch off the radio and transponder! For ME, that's a good enough margin. And it is very compact, with a height of only 3 inches, perfect for the upper firewall shelf of a KR. Best of all, it weighs 13.5 pounds, half the weight of a 35Ah Gill! The icing on the cake is that I ordered it for $64 from one of Hawker's suppliers, Battery Specialties, Inc (1-800-854-5759). That's half what Wicks charges. Battery Specialties is the third place I called, and they just happen to have a bunch of these on order, and they'll be getting them in 4 weeks. More typical is a 6 month waiting list! There must be a reason why these things are in such high demand.Yes, I'll do the testing to make sure that my electrical system has a sufficient margin of safety (after all, my wife's going to be flying this thing, along with my kids, someday), and if I need to, I can add another 13Ah battery (11 pounds) for a backup battery. These two batteries COMBINED weigh less than a Gill, and have almost the same reserve current capacity, but far more cranking power. If you're not inclined to live on the edge like me, you could always buy the G12V26EP for $98 and have one FINE 26Ah battery, with 800 CCA and the potential to mount in any orientation. I also discovered the Interstate U1-33AGM, a 33Ah battery that you should be able to get at your local Interstate dealer for about $85. It uses the same AGM technology and is also permanently sealed like the others I've mentioned.===========================Oscar ZunigaSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________
Dick Navratil writes->With this weight I might consider installing a 35 amp battery in the>nose (35 lb.) for a transponder and radio.Do you want to consider some weight savings? Here's a snip from Mark Langford's KR website that relates his investigation on batteries. Much of what Mark was investigating relates to the requirement for cold cranking amps for a starter, so keep that in mind if you don't need starter juice:====================================I'm always looking to save weight, and was quite intesrested in the Black Panther batteries in the Wicks catalog. They list one that has 600 CCA (cold cranking amps) that I later discovered is a 16Ah (at 10 hours) battery, for $113. I looked at Gills, Bells, Interstates, etc, and finally came full circle to the actual manufacturer of the Black Panther, which is Hawker Energy Products. The standard aircraft batteries are typically 25 or 35 Ah. The AGM technology used in the Hawker Genesis batteries makes them very reliable and with an amazingly high CCA value for cranking things like large 6 cylinder Corvair engines. They are also permanently sealed (by definition) and can be mounted in any orientation.My KR2S electrical system is going to be very current miserly. My radio and transponder are Terra (less than 2A combined), strobes are Kuntzlemann (less than 2A draw), ignition is coil and points (1A per 1000 rpm, according to William) totaling 3A at cruise, and my nav lights are super bright LEDs (Stefan Belatchev's idea) that draw less than .1A. All of this can be turned off so that only the engine's coil and fuel pump are running, which totals 3.7 amps. My ignition switch will control ignition coil and fuel pump without a breaker inline (if either quits, you're going down anyway), but all other electrical items will be separate and will have breaker/switches. The G12V16EP battery that I chose will run this "minimum load" for 4 hours! And if my Corvair runs anything like the rest of my cars, it'll start in 1 or 2 seconds, mininizing starting drain.My EIS (Engine Information System) has programmable alarms, and the voltage trigger level can be set to something like 13 volts so that if my alternator quits charging, the EIS will immediately notify me and I'll have something like 2 hours to find a landing spot even without bothering to switch off the radio and transponder! For ME, that's a good enough margin. And it is very compact, with a height of only 3 inches, perfect for the upper firewall shelf of a KR. Best of all, it weighs 13.5 pounds, half the weight of a 35Ah Gill! The icing on the cake is that I ordered it for $64 from one of Hawker's suppliers, Battery Specialties, Inc (1-800-854-5759). That's half what Wicks charges. Battery Specialties is the third place I called, and they just happen to have a bunch of these on order, and they'll be getting them in 4 weeks. More typical is a 6 month waiting list! There must be a reason why these things are in such high demand.Yes, I'll do the testing to make sure that my electrical system has a sufficient margin of safety (after all, my wife's going to be flying this thing, along with my kids, someday), and if I need to, I can add another 13Ah battery (11 pounds) for a backup battery. These two batteries COMBINED weigh less than a Gill, and have almost the same reserve current capacity, but far more cranking power. If you're not inclined to live on the edge like me, you could always buy the G12V26EP for $98 and have one FINE 26Ah battery, with 800 CCA and the potential to mount in any orientation. I also discovered the Interstate U1-33AGM, a 33Ah battery that you should be able to get at your local Interstate dealer for about $85. It uses the same AGM technology and is also permanently sealed like the others I've mentioned.===========================Oscar ZunigaSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________