Yippee! Charging The Lithium Polymer Beast

[Steve_B]

Here's some inspiration for you:

http://www.wattflyer.com/forums/showthread.php?t=63918

Only 12V, but lots of amps!

I'm really not sure i follow the logic of this approach?

Option 1 - large scale e-power plane with gas generator powered field charger:
You take some gas and put it in a smelly, noisy, expensive, temperamental, heavy and cumbersome gas engine generator. You use the generator to charge a heavy unwieldy lead acid battery, which in turn powers a expensive high power LiPo/LiFe charger which charges your big heavy expensive LiPo/LiFe batteries. After the generator has chugged away for maybe 20-30 minutes or so and you are nauseous due to fumes and deaf with the noise, you then take said battery, put it in your e-power plane and fly for maybe 6 minutes.

Repeat the whole long and painful process for the next flight.

Option 2 - large scale gas power plane:
You don't bother with any of the above mentioned equipment or huge truck that you need to lug it all to the field, thereby saving a small fortune and the inconvenience of humping around literally hundreds of lb of hardware. You put the gas straight into the fuel tank of a gas powered plane and go fly for 12 minutes

Repeat as many times as you like in the time it takes to fill up a gas tank.


And the reason for choosing option 1 is........

 

[njswede]

I'm really not sure i follow the logic of this approach?

...

And the reason for choosing option 1 is........

Well, you know Dennis too, don't you? He's a bit of (OK, GROSS understatement here) an ePower geek.

But actually, we've been thinking of something similar at one of my fields. There we have a bunch of marine lead batteries powered by solar cells. Most of the time that works fine, but during busy weekends we drain the batts faster than the solar cells can power them. It would be nice to have a generator we could pull out and use to charge them up.

 

[Steve_B]

I guess it makes a lot more sense if you have a flying club owned generator permanently stored at your field, along with somewhere secure to store it etc.

 

[SnowDog]

I guess it makes a lot more sense if you have a flying club owned generator permanently stored at your field, along with somewhere secure to store it etc.

This is what we have....a very generous club member donated a generator (old, well used, construction-grade, but still works fine) to the club. Everything just got moved to winter storage, but in the spring we will bring it out, build a secure "hutch" for it, and then we will (finally) have a field-based generator for everyone to use. No need to charge marine lead batteries...just plug the chargers directly into the generator and charge away!

I've had to lug a very large (7500W) generator to the field a few times this year and that is not fun (and back-breaking).

 

[wedoitall]

the link below pretty much show how to make a 12V and 24 V power supply out of computer Power Supplys(pretty cheap) site has some other nice lil info on chargers, lipos, wiring diagrams, how to choose a charger and PS, reviews on chargers, lipos, wattmeters.

https://sites.google.com/site/tjinguytech/my-projects/diy-24v-47a

 

[jocanon]

I purchase and test a lot of these PSUs and since they are re-purposed (used) sometimes they do fail when I test them under load. You usually know pretty quickly which ones are going to fail and which are still solid...point is, one thing you get when you purchase from me versus DIY is the peace of mind that comes with a 1 year warranty...you also will know that it is done correctly (DC isolated properly...) and save the time of making it yourself, that is more time you can spend flying . Oh, and don't forget the power cord with on/off switch I am throwing in with each purchase (the PSUs do not have an on/off switch built in, so you would either need an external power strip or to plug and unplug them each time).

 

[gyro]

I purchase and test a lot of these PSUs and since they are re-purposed (used) sometimes they do fail when I test them under load. You usually know pretty quickly which ones are going to fail and which are still solid...point is, one thing you get when you purchase from me versus DIY is the peace of mind that comes with a 1 year warranty...you also will know that it is done correctly (DC isolated properly...) and save the time of making it yourself, that is more time you can spend flying . Oh, and don't forget the power cord with on/off switch I am throwing in with each purchase (the PSUs do not have an on/off switch built in, so you would either need an external power strip or to plug and unplug them each time).

I'm a believe in SolidHobby's products, I use the swtich myself and love it. I used to have to unplug my cord every time I was done charging... not any more!

Also, as soon as I need to move from my current 12v setup to a 24v, you can bet I'm going to buy from SolidHobby. I'm sure I could do it myself, but I don't have the knowledge or experience he does, and the peace of mind of a 1 year warranty is awesome!

 

[Steve_B]

The SolidHobby PSU looks like a really well done conversion, the best I've seen in fact. Certainly more nicely finished off than my home brew job. I'd certainly run away from any of the conversions you might see that don't have the DC isolation mod done (which is a fiddly little job).

 

[wedoitall]

The SolidHobby PSU looks like a really well done conversion, the best I've seen in fact. Certainly more nicely finished off than my home brew job. I'd certainly run away from any of the conversions you might see that don't have the DC isolation mod done (which is a fiddly little job).

you got an excellent point and those units do look really well done. im sure my wife would feel more confident in the SolidHobby unit hooked up in the house also, as compared to my self done unit.

 

[dth7]

I'm really not sure i follow the logic of this approach?

Option 1 - large scale e-power plane with gas generator powered field charger:
You take some gas and put it in a smelly, noisy, expensive, temperamental, heavy and cumbersome gas engine generator. You use the generator to charge a heavy unwieldy lead acid battery, which in turn powers a expensive high power LiPo/LiFe charger which charges your big heavy expensive LiPo/LiFe batteries. After the generator has chugged away for maybe 20-30 minutes or so and you are nauseous due to fumes and deaf with the noise, you then take said battery, put it in your e-power plane and fly for maybe 6 minutes.

Repeat the whole long and painful process for the next flight.

Option 2 - large scale gas power plane:
You don't bother with any of the above mentioned equipment or huge truck that you need to lug it all to the field, thereby saving a small fortune and the inconvenience of humping around literally hundreds of lb of hardware. You put the gas straight into the fuel tank of a gas powered plane and go fly for 12 minutes

Repeat as many times as you like in the time it takes to fill up a gas tank.


And the reason for choosing option 1 is........

This is my thinking. I have the 6 Cell setup with the EF EXtra 60". I am thinking my best route is the Solid Hobby 24+ with an icharger unit with the parallel boards and plan to charge at home or somewhere that has a generator. Perhaps a deep cycle battery. If I go bigger than the 6 cell I can't see why I wouldn't go 30cc or more and get into gas. The challenge seems to be charging the bigger batteries. By the time you get the batteries, charger, power supply, something to power the power supply I just don't see the benefit over gas.