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Old Apr 05, 2004, 07:18 AM
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New York
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Bandit + B40-8S Battery Advice

OK Bandit Flyers,

Now's your chance to weigh in what you consider the best nicad battery pack configuration for a Bandit running on a B40-8S 4.4:1 with CAM 13/7 prop.

Objective: lively performance on the minimum number of cells and weight. Willing to trade off some performance for lightest wing loading to make landings as uneventful as possible.

No Lipos, perfer not to use NiMH. Would like use either 1300 or 1700 CPS cells if possible.

Your thoughts?

Regards,

Steve
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Old Apr 05, 2004, 08:36 AM
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Calgary, Alberta, Canada
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Why so averse to NiMH?

If you want to keep the weight down and get decent capacity, the 1950 FAUP is a good cell. It's also good to some pretty high current draws...much more so than the CP 1300.
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Old Apr 05, 2004, 10:52 AM
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Regarding NiMH cells, I use them to power my RXs and they seem to false peak on a fairly regular basis when I charge them. Maybe the larger motor battery cells are different. My charger is a Schulze 636 with the most current software.
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Old Apr 05, 2004, 11:19 AM
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Calgary, Alberta, Canada
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That's weird. My Schulze 636+ has never false peaked on me before. What rate are you charging your TX batts at? I have found that with some NiMH's the peak is so small when charging at a low rate (or never comes at all). By charging a bit faster, the peak is more pronounced.

That said, the low IR motor cells charge just like Nicads. You can hit them hard, and they peak very well. I regularly charge GP-3300's in full auto mode on my Schulze at 8A and they take a beating like you would not believe. The 1950 FAUP's are a very good cell, and I'm certain the full auto NiMH mode in your Schulze will charge them quickly, fully and reliably every time.

Hope that helps a bit,

Ryan
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Old Apr 05, 2004, 11:48 AM
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eye_rc_soar's Avatar
College Park, Maryland, United States
Joined Nov 2003
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Steve

You're using old tech when using NiCad, nothing wrong but there is so much better to be had using NiMH. Look closer at GP3300 or FAUP1950 cells. There are the cells to use. Less weight & better amp draw than equivalent NiCad.

False peaking with NiMH RX packs...are you using #1 charge jack on Schultz 636. You will do better with using #2 jack. This is the charge jack for low cell count packs.

...don
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Old Apr 05, 2004, 01:39 PM
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Thanks guys, I am using the #1 jack for charging RX NiMH RX packs, will definitey try the #2 jack. Typcially I just set the 636+ to NiMH mode and let it charge on auto.

Regarding the Bandit, any thoughts as to the number of cells? My sense is it's somewhere in the 8-10 cell range. Since I'll start off by using this plane for a bit of sloping, I don't need lots of duration, perhaps the FAUP 1950 cell size is best.

Thanks,

Steve
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Old Apr 05, 2004, 02:06 PM
I invented electricflight
I am from northern nj exit 19 off 80 make a left
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packs

I fly mince on 8 1900's. wehyn those run out i use 10 cell 1700 scr packs. Im not using a b40 but a motor with simular kv and amp draw. on both the 1900's and the 1700 landing are no problem. I flew it for a week or so on 10 2400's, its all i had. the climbs and dives were great but the landing needed to be very fast, too fast for enjoyment.

thanks,
dan

oops edited
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Old Apr 05, 2004, 10:31 PM
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Atlanta Hartsfield, Georgia, United States
Joined Apr 2002
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8 cells 1950 FAUP on that setup. Prop it up to about 50 amps, and it'll be great. You could push it a bit more, but thats getting on up there for the 8S.

~~fred
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Old Apr 05, 2004, 10:44 PM
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Melbourne , Outer East .
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G`day Steve
I`ve only used cp-1700 & cp1300 in my Bandit but I`ve just purchased an 8 cell pack of faup1950 & will give them a try this weekend , from everyone I`ve spoken to their the way to go . Weight wise they fall in the middle of the 1300 & 1700 . My Bandit auw is 44.5 oz with the 1700 pack . I don`t really notice the difference weight wise when landing between the different packs . The Bandit slopes well in good lift & you`ve allways got electric lift when required .
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Old Apr 06, 2004, 05:10 AM
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Australia, ACT, Canberra
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I just put a B-40 8S into my Omega, I have 7 FAUP's to use with it and was going to use a 13X7 but Pcalc says a 12X9 will give more thrust and more speed on 3 amps less than the 13 X 7.
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Old Apr 06, 2004, 07:26 AM
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New York
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Thanks guys, just ordered an 8 cell 1950 FAUP pack. By the way, do you let your RX antenna just stream out the back, wrap around a straw, etc.? Anyone try the new Sticky Base Loaded Antenna from RC Direct?
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Old Apr 06, 2004, 07:54 AM
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Mine exits the fus just behind the wing and is taped to the top of the fin, both on my Omega and Absolute.

Cheers
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Old Apr 08, 2004, 04:22 AM
85 degrees and sunny
glide's Avatar
Hawaii
Joined Apr 2003
554 Posts
SteveR:

I have the same setup as you have on your Bandit. I use an 8 cell battery pack of CP1700SCR. I get vertical performance and great battery time. I got my packs from Diversity Model Aircraft and I got the "zapped" version. Dave of DMA is a great guy. With the same setup as you I measured 450 watts and 67 amps on the Whattmeter.
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Old Apr 08, 2004, 06:44 AM
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New York
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Thanks Glide. I agree with your assessment of DMA, I buy all my packs from him and his quality and service are second to none. I'll soon have both an 8-cell 1700 pack and 8-cell 1950 pack, will be interesting to see how they both perform.

Will also install one of the new RC Direct Sticky RX antennas. Pretty neat product: it's a base loaded antenna that's basically a thin flexible piece of printed circuit material. Will let you know how everything works out.
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