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#1
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Could this be used in a sailplane?
If I had one of these ......
http://www.batterystuff.com/solar-chargers/ ......would I be able to fly continously without ever removing the battery and charging it overnight? I figured there's alot of smart folks on here who have already thought this through! Scott |
#2
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Could this be used in a sailplane?
On Jun 29, 7:26*am, Spam wrote:
If I had one of these ...... http://www.batterystuff.com/solar-chargers/ .....would I be able to fly continously without ever removing the battery and charging it overnight? I figured there's alot of smart folks on here who have already thought this through! Scott This is true, search this message board. Unless you are powering just a radio and vario I doubt if you would get enough power fron cell inside on the glaresheild. However, I just saw a SUNPOWER 60 watt kit at COSTCO, less than $5/ watt including inverter and charger and controller. Much better prices than your link.. One could put a single 15w panel on your trailer and the battery would be charged before you launch probably... MM |
#3
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Could this be used in a sailplane?
There are also flat panels that you can inlay behind the cockpit. I
have 5mAh to keep the batteries topped off in flight. |
#4
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Could this be used in a sailplane?
I use one of these:
http://www.harborfreight.com/cpi/cta...emnumber=44768 View the product manual for details. At 1.5 watt it keeps a small motorcycle battery charged indefinately for powing a typical instrument panel with radio and audio varios etc. a 5 watt panel might be too much and will need a good charge reulater so as not to cook the battery. It is only 14" x 6"x7/8" and I mount it near the nose under the canopy so as not to cause glare and is out of my sight lines. Typically on sale for $12 every couple months. It has a nice little remote flashing light to show that it is charging and is regulated so as not to cook the battery. Ray |
#5
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Could this be used in a sailplane?
jb92563 wrote:
I use one of these: http://www.harborfreight.com/cpi/cta...emnumber=44768 View the product manual for details. At 1.5 watt it keeps a small motorcycle battery charged indefinately for powing a typical instrument panel with radio and audio varios etc. a 5 watt panel might be too much and will need a good charge reulater so as not to cook the battery. You need to measure your current drain before getting too excited about solar panels. A PDA can draw 300-400 ma; for a 5 hour flight, that's 1.5 to 2 amphours. A 5 watt panel can put out, at most, about 300 ma with perfect alignment to the sun. On a glider in flight, it will likely supply an average of maybe 100 ma. Do the math. Sitting on the ground, it will still not be perfectly aligned with the sun, so even when you count the amps over a full day, it might not keep up with the PDA, and you still have a radio, vario, gps, maybe more. Result: 1.5 watt is quite inadequate for the typical glider, and you need solar panels that can put out at least twice the normal current drain to just keep up. Of course, if you fly only 2 or 3 hours a day, you can get by with smaller panels. The reason pilots are willing to pay the big bucks for the Strobl solar panels is they put out a lot of current for their size, so they can actually keep up with the typical radio, vario, gps, PDA, and (with four panels) a transponder. An alternative is to charge your glider battery from another 12 volt panel, using a Multiplex Ln-5014 DC-DC charger (or similar). Much cheaper, and you don't need to install solar panels on the glider. The DC charger battery can be charged by an AC charger or small solar panels during the day. -- Eric Greenwell - Washington State, USA * Change "netto" to "net" to email me directly * "Transponders in Sailplanes" http://tinyurl.com/y739x4 * Sections on Mode S, TPAS, ADS-B, Flarm, more * "A Guide to Self-launching Sailplane Operation" at www.motorglider.org |
#6
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Could this be used in a sailplane?
On Jul 4, 8:32*pm, Eric Greenwell wrote:
jb92563 wrote: I use one of these: http://www.harborfreight.com/cpi/cta...emnumber=44768 View the product manual for details. At 1.5 watt it keeps a small motorcycle battery charged indefinately for powing a typical instrument panel with radio and audio varios etc. a 5 watt panel might be too much and will need a good charge reulater so as not to cook the battery. You need to measure your current drain before getting too excited about solar panels. A PDA can draw 300-400 ma; for a 5 hour flight, that's 1.5 to 2 amphours. A 5 watt panel can put out, at most, about 300 ma with perfect alignment to the sun. On a glider in flight, it will likely supply an average of maybe 100 ma. Do the math. Sitting on the ground, it will still not be perfectly aligned with the sun, so even when you count the amps over a full day, it might not keep up with the PDA, and you still have a radio, vario, gps, maybe more. Result: 1.5 watt is quite inadequate for the typical glider, and you need solar panels that can put out at least twice the normal current drain to just keep up. Of course, if you fly only 2 or 3 hours a day, you can get by with smaller panels. The reason pilots are willing to pay the big bucks for the Strobl solar panels is they put out a lot of current for their size, so they can actually keep up with the typical radio, vario, gps, PDA, and (with four panels) a transponder. An alternative is to charge your glider battery from another 12 volt panel, using a Multiplex Ln-5014 DC-DC charger (or similar). Much cheaper, and you don't need to install solar panels on the glider. The DC charger battery can be charged by an AC charger or small solar panels during the day. -- Eric Greenwell - Washington State, USA * Change "netto" to "net" to email me directly * "Transponders in Sailplanes"http://tinyurl.com/y739x4 * * * Sections on Mode S, TPAS, ADS-B, Flarm, more * "A Guide to Self-launching Sailplane Operation" atwww.motorglider.org And even a 5W panels are very small and may be no use. You've also got to think what problem you are trying to solve, and it if is really a problem. AGM/VRLA batteries (i.e. what almost ll glides use) have such a low self-discharge rate (~1% or so per month) they don't need to be left on a trickle charger. The claims about trickle chargers/battery maintaniers are really for cars or motorbikes not used frequently where there alarm system or other components keeps a constant small load on the battery and/or the flooded lead acid battery discharges at a higher rate (~ order of magnitude or higher) than our batteries do. Further what people think some of these small panels or trickle chargers can do and what they actually do is often different. One apparently common point of confusion is for people to run down their battery and then hook it up to a small panel and then go fly a few days later and look at the voltage and think "wow this little thing has really charged well". In reality what they are likely seeing is a spurious effect called surface charge. Put a decent load on the battery and the voltage will sag within tens of seconds. Then they wonder why the battery is not lasting - it was just not fully charged. I've seen this in club gliders where there is no possible way the small solar panels can keep up with the load and people keep futzing around with small panels to thinking they are helping by "topping off" or "maintain" the battery or whatever. Those batteries should really be put on a proper AC charger for an AGM battery, or hooked up to a *large* solar panel and charge controller (60W, 100W, 200W, pick your poison but it's not going to be 1 W or 10W) and maybe secondary battery (like Eric suggests) and DC to DC charger to quickly charge them back to full capacity. An AGM battery sitting around at low state of charge will damage the battery eventually so you want to get it back to near full charge quickly. A charge controller is really not needed on a 5W or 10W or so panel. And these really small panels may not be the right thing to use at all. Darryl |
#7
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Could this be used in a sailplane?
"Darryl Ramm" wrote in message ... A charge controller is really not needed on a 5W or 10W or so panel. And these really small panels may not be the right thing to use at all. I am sorry, but I strongly disagree with this point, especially with the small batteries we use in gliders. You will never go wrong by using a charge controller. To not use a charge controller is to risk early battery death through overcharging. (Much depends on the open-circuit voltage of the panel) I learned this by ruining several large, expensive, batteries using only a 1 amp (12 watt) trickle charger. Vaughn |
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