[Max]

Not worth it IMHO.

Something else to schlep to and from the field, having to hook it up, laying it out in the sun.. What a hassle. for what? 5W is nothing.

Last fall I hooked up a 4S 5A Lipo to my starter:



Now I ditched the stupid (AND HEAVY) flight box battery in favour of this lightweight and reliable setup. I used it all summer with no problems. One stretch between charges, I used it for 3 weeks of starting and I only used HALF the rated capacity.

So all you need is one of these and a Ni-Starter. The advantage? Both can be field-charged on your car battery if they ever go low while at the field.

Now I have discovered that the 4S 5A Lipo is overkill.

One member at our club made this mod with a 3S 1800mah Lipo and he uses it all day with no problems. It starts up to a 120 4S with no problems. (maybe even bigger, but that is the biggest engine he has) Recharging only takes an hour when he gets home (which is not out of the ordinary for anyone who flies electrics)

[moo]

Originally Posted by chansen

Ya, you are right regarding the formula, but I was just copying what was on the back of the Solar Panel's box. And it is only ment for top-op, and do not forget to put a diode in line, a 5 volt should do.
Cato.

SLA batteries are so 19th century, this is the 21st.

(just kidding, I know of many uses for them)

[rcjetguy]

Not quite the same setup here, but thought I would share.

Two years ago I designed & built a 12 volt system for my club. I scrounged 2 used but good 225 ah 12 volt batteries, & bought a CTC 15 watt solar panel. I made 3 electric outlet boxes & installed them in our starting area. Everyone now uses these instead of lugging their field batteries out. Best part is, I don't take the batteries out in the winter. They have worked perfectly. We also have 2 trainers & transmitters which we keep charged all summer with this supply also (through modified chargers).

Anyone contemplating something like this. I'd be glad to give some (lots) pointers.

Rcjetguy

[channel38]

I bought a solar power panel years ago and never used it.
Just took it outside and it was putting out 21 volts.

dj
channel38 (on FM)

[Shawn_1976]

21 volts is normal. They all have high open circuit voltage. But when in use it is lower. Every panel needs to have a voltage regulator or controller. Most of the cheap crapy tire ones have them built in.

[Wayne V]

Originally Posted by Shawn_1976

21 volts is normal. They all have high open circuit voltage. But when in use it is lower. Every panel needs to have a voltage regulator or controller. Most of the cheap crapy tire ones have them built in.

That is true, when you hook up one of these small panels to a battery the battery acts as the regulator, i have one of the 1W panels hooked up to a 9AH battery outside, it's been charging for a week and when the sun is not on the panel i get 12.2v, the voltage in full sun goes upto about 12.5v, so basically all these small panels do is keep the battery topped off.

[rubbie]

So just to be clear what kind of diode do I need,just to keep the field box batteries topped up (1.8v unit)

Thanks guys

[Riddick]

Most of these panels have the diode in the circuitry all ready, but any 12v diode should do.

[canadianf1pilot]

bought 2 of 'em last week...they are handy for the flight box battery and the battery in the camper

Bill

[rubbie]

These are really great units for keeping my a spare car battery that I carry in the back of my jeep charged and my field box topped up. My car sits all day in the Go train lot so i do have the "time" that other guys may not have. I did by a couple units (1.0 w) to keep the battery in the boats at the cottage topped up as well, these are so handy and they are the weather proof ones.

I didn't need the solenoid after all it didn't discharge the battery at night.