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#21
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New Battery Type?
On Saturday, November 28, 2020 at 4:07:14 PM UTC-8, kinsell wrote:
On 11/26/20 2:55 PM, AS wrote: On Thursday, November 26, 2020 at 1:02:00 PM UTC-5, Eric Greenwell wrote: AS wrote on 11/26/2020 8:59 AM: On Thursday, November 26, 2020 at 11:19:57 AM UTC-5, wrote: I have used such a battery since July. Works just fine for me in my ASG 32 Mi with lots of electronic stuff. /Robert So there is already some operational experience with this type of batteries, which is good to hear. The warnings about the initially high voltage of 16+V is well taken. I checked the spec's of the stuff I have on and behind my panel and most of it is limited to only 15V. That would lead me to more follow-up questions for the experts: - what would happen if this battery was charged with only 15V? - if the above is not advisable, would the use of an electronic voltage regulator like this one be an option? https://vetco.net/products/dc-dc-adj...kaAnEdEALw_wcB - I am not familiar with this type of electronics but reading the specifications of it, I see a 'Ripple Frequency' of 150kHz on the output. Could that mess up the electronics? Thanks for any constructive replies. The voltage regulator might cause radio and other interference, adds complexity, and one more item to fail, possibly damaging the devices it was supposed to protect.. There seems to be no sufficient reason to consider this chemistry, compared to LiFe batteries, unless you are space limited, due to higher cost and risk of over-voltage. Is battery space insufficient on your glider? -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) - "A Guide to Self-Launching Sailplane Operation" https://sites.google.com/site/motorg...ad-the-guide-1 Good points, Eric. I currently have room for and use two 12V LiFe batteries (K2) but I get low voltage warnings on my SN10b fairly early into the flight when keying the radio, a KTR72N. The batteries are only two seasons old. I may have some other, more power hungry equipment, like a Volkslogger functioning only as the GPS source, which may have a higher draw. My goal is to get rid of the Volkslogger but in parallel, I was thinking about upgrading the batteries. However, that seems to be not as easy as cleaning up my panel. Uli 'AS' Just to pile on a little bit more, the type of battery you're looking at is commonly called lithium-cobalt and isn't new at all. Someone at Boeing thought it sounded really neat, and designed it into the 787. After a few fires, they 'fixed' the problem by putting them in steel containment boxes with blowout plugs to the atmosphere. https://www.youtube.com/watch?v=rvkEpstd9os&t=280s Switching to a battery like that in order to fix what is likely a wiring issue isn't a good idea. The NMC chemistry is being used by most electric car manufacturers (except, notably, Tesla) as well as electric gliders. It does not have the stability of LFP chemistry, however. The reasons for this are discussed in detail in: https://www.nature.com/articles/s41467-020-15355-0#Tab3 A friend of mine cancelled his order for a GP15 because, among other things, it can't be flown with a parachute (it uses a ballistic chute instead). He didn't like the prospect of the thing catching fire. As others have said, you most likely have a wiring issue. Look at the voltage drop at each point in the wiring to the SN10b to find the culprit. I fly with a Bioenno LFP battery and have none of your issues. And I have a full glass panel with transponder and Flarm. Tom |
#22
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New Battery Type?
At 16:59 26 November 2020, AS wrote:
On Thursday, November 26, 2020 at 11:19:57 AM UTC-5, w= rote: I have used such a battery since July. Works just fine for me in my ASG 3= 2 Mi with lots of electronic stuff.=20 =20 /Robert So there is already some operational experience with this type of batteries= , which is good to hear. The warnings about the initially high voltage of 1= 6+V is well taken. I checked the spec's of the stuff I have on and behind m= y panel and most of it is limited to only 15V.=20 That would lead me to more follow-up questions for the experts: - what would happen if this battery was charged with only 15V? =20 - if the above is not advisable, would the use of an electronic voltage reg= ulator like this one be an option? https://vetco.net/products/dc-dc-adj...-down-voltage- regulator-mod= ule-with-volt-meter-d92? gclid=3DCj0KCQiAwf39BRCCARIsALXWETz1ec6W-C6QcqB57EE= nZ5_ejcqc_VjaXarrYW8J-9hJiGyYLnUmczkaAnEdEALw_wcB - I am not familiar with this type of electronics but reading the specifica= tions of it, I see a 'Ripple Frequency' of 150kHz on the output. Could that= mess up the electronics? Thanks for any constructive replies. Uli 'AS' If you are going to put a 'power limiter' in the supply line then use something linear not switching. Linear supplies dump extra power in the form of heat. Switching power supplies make electrical noise unless they are properly constructed and shielded ( ie expensive ) Knocking up a power regulator for this type of applicaion is barely worth the effort. One or even two simple diodes placed in series with the main positive feed to those instruments rated at a lower maximum voltage provides a safe and secure way to simply drop the voltage into that device. As a side effect, you get additional reverse polarity protection to your instruments! for most instruments, a 1N4007 1 Amp diode would suffice. it drops about 0.7v at very small currents and 1v at its maximum rating of 1 Amp. A glass screen device might need a diode rated a little higher at say 2 or 3 Amps. It might just be simpler to put a big diode rated at 20 amps or so in line with the battery. A STTH20R04 will easily handle that sort of current and give you an overall 0.6v minimum drop up to 1.5 drop at 20 Amps. These things are pennies even in single quantities. |
#23
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New Battery Type?
On 11/28/2020 11:29 PM, Ian Molesworth wrote:
Seru=iously? SERIOUSLY?? If you are going to put a 'power limiter' It's a VOLTAGE limiter, not a POWER limiter. in the supply line then use something linear not switching. Linear supplies dump extra power in the form of heat. Switching power supplies make electrical noise unless they are properly constructed and shielded ( ie expensive ) Knocking up a power regulator for this type of applicaion is barely worth the effort. Its not worth the effort as HE SHOULD USE AN APPROPRIATE BATTERY. A PROPERLY DESIGNED switcher DOES NOT need to radiate noise! A switcher designed by a moron, well that's another story... One or even two simple diodes placed in series with the main positive feed to those instruments rated at a lower maximum voltage provides a safe and secure way to simply drop the voltage into that device. As a side effect, you get additional reverse polarity protection to your instruments! Gee, I've recently documented a couple FIRES started that way! Diodes DISSIPATE HEAT and WASTE ENERGY. If they are not properly heat-sunk, YOU GET A FIRE. Please do not try this at home. YIKES. Even for RAS... |
#24
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New Battery Type?
On Friday, November 27, 2020 at 11:01:36 AM UTC-5, Mark Mocho wrote:
I've rewired and/or replumbed my panel three or four times over the years as new equipment is added and old things are removed. Upgrading flight computers, displays, radios, transponders and the like have greatly enhanced the cockpit environment. One thing I have found invaluable is John DeRosa's series of helpful tips on glider maintenance. (http://aviation.derosaweb.net/presentations/) The "Aviation Electrical Best Practices" presentation shows the "right" way to go about wiring a cockpit. If you have any electrical skills, whether in industrial or home wiring, you will find the particular requirements for aviation are different. This guide steers you in the right direction. Thanks to "OHM" for these guides. As to "rewire the rat's nest": I have never purchased a "new" glider, only a "used" one. In every case, there have been tubing and wiring issues and in each case I undertook to re-wire and re-tube everything I could get at. In every case, I have discovered something that was at least puzzling if not down-right scary. You don't have to be a wizard to discover problems and correct them. Just take it one thing at a time, get everything neat, and you will have a lot more fun come spring than if you don't. Yes, I have been using his advice for a while now. Good stuff. I have 9 AH LA batteries and have always tested them this time of year by putting a 10 ohm 25 watt resistor across the output and taken voltage readings each hour down to 9 VDC or so. If the battery doesn't go 4-5 hours, I replace it. So how does one "check" a LiPo? Anyone done it? As a side note, I was informed in the owner's literature never to put two of their LiPo's in parallel, as you can with the LA type. Read the manual if you have any parallel circuits in your ship before deploying in this manner. |
#25
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New Battery Type?
On Wed, 02 Dec 2020 22:19:51 -0800, Jay Campbell wrote:
On Friday, November 27, 2020 at 11:01:36 AM UTC-5, Mark Mocho wrote: I've rewired and/or replumbed my panel three or four times over the years as new equipment is added and old things are removed. Upgrading flight computers, displays, radios, transponders and the like have greatly enhanced the cockpit environment. One thing I have found invaluable is John DeRosa's series of helpful tips on glider maintenance. (http://aviation.derosaweb.net/presentations/) The "Aviation Electrical Best Practices" presentation shows the "right" way to go about wiring a cockpit. If you have any electrical skills, whether in industrial or home wiring, you will find the particular requirements for aviation are different. This guide steers you in the right direction. Thanks to "OHM" for these guides. As to "rewire the rat's nest": I have never purchased a "new" glider, only a "used" one. In every case, there have been tubing and wiring issues and in each case I undertook to re-wire and re-tube everything I could get at. In every case, I have discovered something that was at least puzzling if not down-right scary. You don't have to be a wizard to discover problems and correct them. Just take it one thing at a time, get everything neat, and you will have a lot more fun come spring than if you don't. Yes, I have been using his advice for a while now. Good stuff. I have 9 AH LA batteries and have always tested them this time of year by putting a 10 ohm 25 watt resistor across the output and taken voltage readings each hour down to 9 VDC or so. If the battery doesn't go 4-5 hours, I replace it. So how does one "check" a LiPo? Anyone done it? As a side note, I was informed in the owner's literature never to put two of their LiPo's in parallel, as you can with the LA type. Read the manual if you have any parallel circuits in your ship before deploying in this manner. I use an old Pro-Peak Prodigy II to cycle and measure my battery capacity each year. I sling 7.2AH SLAs once they drop below 5 Ah capacity but of course ymmv. The Pro-Peak Prodigy II handles multiple battery chemistries (SLA, NiCd, NiMH, LiPo) and can discharge and recharge any of them. Check out your local RC model shop or website and you'll find similar systems for reasonable prices. Mine self-limits to 400mA discharge and charges at a similar rate and can be run off a battery or a mains adapter: the electric RC guys take their chargers to the flying field and charge models from their car battery. -- -- Martin | martin at Gregorie | gregorie dot org |
#26
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New Battery Type?
On 12/3/2020 8:31 AM, Martin Gregorie wrote:
On Wed, 02 Dec 2020 22:19:51 -0800, Jay Campbell wrote: On Friday, November 27, 2020 at 11:01:36 AM UTC-5, Mark Mocho wrote: I've rewired and/or replumbed my panel three or four times over the years as new equipment is added and old things are removed. Upgrading flight computers, displays, radios, transponders and the like have greatly enhanced the cockpit environment. One thing I have found invaluable is John DeRosa's series of helpful tips on glider maintenance. (http://aviation.derosaweb.net/presentations/) The "Aviation Electrical Best Practices" presentation shows the "right" way to go about wiring a cockpit. If you have any electrical skills, whether in industrial or home wiring, you will find the particular requirements for aviation are different. This guide steers you in the right direction. Thanks to "OHM" for these guides. As to "rewire the rat's nest": I have never purchased a "new" glider, only a "used" one. In every case, there have been tubing and wiring issues and in each case I undertook to re-wire and re-tube everything I could get at. In every case, I have discovered something that was at least puzzling if not down-right scary. You don't have to be a wizard to discover problems and correct them. Just take it one thing at a time, get everything neat, and you will have a lot more fun come spring than if you don't. Yes, I have been using his advice for a while now. Good stuff. I have 9 AH LA batteries and have always tested them this time of year by putting a 10 ohm 25 watt resistor across the output and taken voltage readings each hour down to 9 VDC or so. If the battery doesn't go 4-5 hours, I replace it. So how does one "check" a LiPo? Anyone done it? As a side note, I was informed in the owner's literature never to put two of their LiPo's in parallel, as you can with the LA type. Read the manual if you have any parallel circuits in your ship before deploying in this manner. I use an old Pro-Peak Prodigy II to cycle and measure my battery capacity each year. I sling 7.2AH SLAs once they drop below 5 Ah capacity but of course ymmv. The Pro-Peak Prodigy II handles multiple battery chemistries (SLA, NiCd, NiMH, LiPo) and can discharge and recharge any of them. Check out your local RC model shop or website and you'll find similar systems for reasonable prices. Mine self-limits to 400mA discharge and charges at a similar rate and can be run off a battery or a mains adapter: the electric RC guys take their chargers to the flying field and charge models from their car battery. I followed others' recommendations and use the iMax B6 charger/discharger. Capable and cheap. But a test with a suitable resistor, voltmeter and clock is also fine. I wouldn't discharge a lead-acid battery down to 9V, that is damaging to its longevity. I'd stop at 10.5V or 11V. Do that when the battery is new and you'll have a baseline to compare to when the battery is older. For a lithium battery you can do a similar test, just expect that the voltage will decline much more gradually for most of the discharge, and then fall rapidly as the battery nears exhaustion. There is very little additional capacity below 11.5V or so. The built-in protection circuit may shut it down between measurements if the voltage falls far enough. That's OK. Just recharge it to turn it back on. |
#27
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New Battery Type?
Jay Campbell wrote on 12/2/2020 10:19 PM:
On Friday, November 27, 2020 at 11:01:36 AM UTC-5, Mark Mocho wrote: I've rewired and/or replumbed my panel three or four times over the years as new equipment is added and old things are removed. Upgrading flight computers, displays, radios, transponders and the like have greatly enhanced the cockpit environment. One thing I have found invaluable is John DeRosa's series of helpful tips on glider maintenance. (http://aviation.derosaweb.net/presentations/) The "Aviation Electrical Best Practices" presentation shows the "right" way to go about wiring a cockpit. If you have any electrical skills, whether in industrial or home wiring, you will find the particular requirements for aviation are different. This guide steers you in the right direction. Thanks to "OHM" for these guides. As to "rewire the rat's nest": I have never purchased a "new" glider, only a "used" one. In every case, there have been tubing and wiring issues and in each case I undertook to re-wire and re-tube everything I could get at. In every case, I have discovered something that was at least puzzling if not down-right scary. You don't have to be a wizard to discover problems and correct them. Just take it one thing at a time, get everything neat, and you will have a lot more fun come spring than if you don't. Yes, I have been using his advice for a while now. Good stuff. I have 9 AH LA batteries and have always tested them this time of year by putting a 10 ohm 25 watt resistor across the output and taken voltage readings each hour down to 9 VDC or so. If the battery doesn't go 4-5 hours, I replace it. So how does one "check" a LiPo? Anyone done it? As a side note, I was informed in the owner's literature never to put two of their LiPo's in parallel, as you can with the LA type. Read the manual if you have any parallel circuits in your ship before deploying in this manner. SLA battery capacity at low to moderate currents (like you are doing) is usually measured down to 11.0 volts for a "100% discharge". Going lower than that causes unnecessary damage that shortens the life of the batter. -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) - "A Guide to Self-Launching Sailplane Operation" https://sites.google.com/site/motorg...ad-the-guide-1 |
#28
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New Battery Type?
On Saturday, November 28, 2020 at 8:30:05 PM UTC-8, Ian Molesworth wrote:
At 16:59 26 November 2020, AS wrote: On Thursday, November 26, 2020 at 11:19:57 AM UTC-5, w= rote: I have used such a battery since July. Works just fine for me in my ASG 3= 2 Mi with lots of electronic stuff.=20 =20 /Robert So there is already some operational experience with this type of batteries= , which is good to hear. The warnings about the initially high voltage of 1= 6+V is well taken. I checked the spec's of the stuff I have on and behind m= y panel and most of it is limited to only 15V.=20 That would lead me to more follow-up questions for the experts: - what would happen if this battery was charged with only 15V? =20 - if the above is not advisable, would the use of an electronic voltage reg= ulator like this one be an option? https://vetco.net/products/dc-dc-adj...-down-voltage- regulator-mod= ule-with-volt-meter-d92? gclid=3DCj0KCQiAwf39BRCCARIsALXWETz1ec6W-C6QcqB57EE= nZ5_ejcqc_VjaXarrYW8J-9hJiGyYLnUmczkaAnEdEALw_wcB - I am not familiar with this type of electronics but reading the specifica= tions of it, I see a 'Ripple Frequency' of 150kHz on the output. Could that= mess up the electronics? Thanks for any constructive replies. Uli 'AS' If you are going to put a 'power limiter' in the supply line then use something linear not switching. Linear supplies dump extra power in the form of heat. Switching power supplies make electrical noise unless they are properly constructed and shielded ( ie expensive ) Knocking up a power regulator for this type of applicaion is barely worth the effort. One or even two simple diodes placed in series with the main positive feed to those instruments rated at a lower maximum voltage provides a safe and secure way to simply drop the voltage into that device. As a side effect, you get additional reverse polarity protection to your instruments! for most instruments, a 1N4007 1 Amp diode would suffice. it drops about 0.7v at very small currents and 1v at its maximum rating of 1 Amp. A glass screen device might need a diode rated a little higher at say 2 or 3 Amps. It might just be simpler to put a big diode rated at 20 amps or so in line with the battery. A STTH20R04 will easily handle that sort of current and give you an overall 0.6v minimum drop up to 1.5 drop at 20 Amps. These things are pennies even in single quantities. Any passive device that drops voltage will be inefficient and do it by converting the power into heat. Low noise switching regulators do not need to be expensive. Here is but one example: https://www.analog.com/en/products/p...gulators.html# https://www.analog.com/en/parametricsearch/11001#/d=5351|5573|5574|5349|5358|5345|5575|5362|5589|s3| s5 These devices also provide current limiting as a bonus Tom |
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