Could this be used in a sailplane?

[Spam]

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

[[email protected]]

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

[CoggFly]

There are also flat panels that you can inlay behind the cockpit. I
have 5mAh to keep the batteries topped off in flight.

[jb92563]

I use one of these:
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=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

[Eric Greenwell]

jb92563 wrote:
> I use one of these:
> http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=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

[Darryl Ramm]

On Jul 4, 8:32*pm, Eric Greenwell > wrote:
> jb92563 wrote:
> > I use one of these:
> >http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=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

[vaughn[_2_]]

"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