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Ozzieflyer
09-15-2005, 02:29 AM
G'day all

Just a quick question I want to throw in to the pot.

I have a 2m Balsacraft Electrafly 600 powered glider. Currently using 7 cell Sanyo 1700 SCR 'car pack' as power. These packs weigh in at 396gr each, including connector.
Last night I also weighed my 7 cell Kan 1050 pack at 166gr.

This means I should be able to paraller two packs of the Kan cells and get both a higher capacity, lighter power option. ie 2100mAh for 332gr - Is this assumption correct?
I am working here on the assumption I charge each pack seperately and then use a two to one adaptor. Using a Watt meter static current WOT was measured at 25A - can the doubled Kan pack take this sort of discharge. I assume this should equate to 12.5A/pack which should be well within there ability?

Lastly I have been looking at converting to Lipo's. Again I assume that if I parallel the packs I can combine the continous discharge current.
eg two 1700mAh 2 cell Lipo at 10C continous = 7.4v 17Ax2 = 34A continous

comments please

PeteH

Matt Kirsch
09-16-2005, 05:27 PM
You understand this far better than you give yourself credit for. I couldn't have explained things better myself. :)

The KAN1050s should do okay on 12.5A as long as you don't run them like that for too long. That's about their max. A couple minutes to climb out then a glide cool-off period, or long stretches of partial throttle is what I'd recommend.

LiPolys, due to their fixed-voltage charge, can be paralleled and left paralleled, even during charges. As long as you use them together, you can charge them together.

ragbag
09-17-2005, 11:37 AM
Sometimes we for get our ESC.

If it isn't lipo friendly we discharge our lipo's down below the minimuim and ruin the lipo pack.:mad:

My thoughts,
By George

Ozzieflyer
09-19-2005, 01:55 AM
Matt & Ragbag

Thanks for your replies. I thought that I had it right but sometimes it's nice to get confirmation before letting the 'magic smoke' out :)
Definately into climb and glide. I want to use this set up to get my kids up and flying before going onto the E-Starter I have made them - bigger, slower, easier to read in the air.
I already fly several LIPO planes so understand about the low voltage issues, but this would represent a major outlay as I have nothing particulary that would suit but thought that two 2S1P packs joined in the plane would be more flexible than a 2S2P pack which would end up dedicated. There is also the issue od cell inbalance which is easier to control if charging two seperate packs.

Thanks again for the feed back

Pete