RE: Got Kokams?  
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RE: Got Kokams? - 12/7/2003 1:55:58 AM   
sniper887


 

Posts: 18
Joined: 11/29/2002
From: Ridgecrest, CA, USA
Status: offline 		Enrique
Regarding your post about charging times I saw this charger on the towerhobbies.com website:

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXCTZ5&P=7

It is actually two separate chargers and it charges transmitter and reciever packs (1-8 cells) and also lithium ion or lithium polymer batteries (1-3 cells) and you can charge two of any type at a time in any combination. Can't beat the price either. I dont' have one but plan on getting one and some kokam 3 cell 1500 packs for my giles. Looks cool.

(in reply to enrique1123)
       Post #: 26

RE: Got Kokams? - 12/8/2003 6:58:31 PM   
Bill Bergman


 

Posts: 2
Joined: 9/10/2003
From: Sugar Land, TX, USA
Status: offline 		Can any one tell me if there is a good motor setup for the Kokam 3 cell 11.1 volt 700ma pack. I've looked at several motor spec sheets and none stay in the useable amp range of this battery at 11.1 volts.

(in reply to sniper887)
       Post #: 27

RE: Got Kokams? - 12/8/2003 9:31:39 PM   
Greg Covey



Posts: 4450
Joined: 5/24/2003
From: Rochester, NY, USA
Status: offline 		Hi Bill,

You can always use this pack with a geared GWS IPS motor, dual IPS motor, Astro Flight 801G, or Speed 280 motor. As long as the current is kept within the motor limits, the additional voltage will provide more power to the prop. Essentially, you can spin the same size prop faster.

The Kokam 700 cell provides a continuous current delivery of about 4amps with a 6-7amp short burst.

For example, lets use a GWS DX-A geared 5.86:1 with a 10x4.7 prop. This typically runs well on a 2-cell LiPo pack.

You can use a GWS DX-C geared 8.6:1 with the same 10x4.7 prop on a 3-cell LiPo pack. It will continue to draw about 2amps at full throttle but spin the prop faster.

For clarity, lets say that each LiPo pack provides 4v. A 2-cell setup then provides 2*4volts * 2amps or 16 watts of power into the motor. The 3-cell pack provides 3*4*2amp or 24watts to the motor.

With proper motor cooling, the higher voltage but limited current will provide a good hop-up. This same approach can be used on a Speed 280 power system. Alternatively, you can parallel the LiPo cells for additional current delivery and capacity.

Check out the specs on the Astro Flight geared 010 motor here. You'll see a good fit for your 3-cell, Kokam 700 pack. Just don't leave it on full throttle for the whole flight.

Good luck!

< Message edited by Greg Covey -- 12/8/2003 9:51:57 PM >

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(in reply to Bill Bergman)
       Post #: 28

RE: Got Kokams? - 12/9/2003 2:32:05 PM   
Bill Bergman


 

Posts: 2
Joined: 9/10/2003
From: Sugar Land, TX, USA
Status: offline 		Thanks Greg!

(in reply to Greg Covey)
       Post #: 29

RE: Got Kokams? - 12/11/2003 10:15:11 PM   
pnsimons


 

Posts: 2
Joined: 9/24/2003
From: columbus, OH,
Status: offline 		Greg,

Nice web site. Thanks for your input in the rcuniverse forums. How do I limit current and get the Hop-up you talked about in a recent post? Concerning Li-polys.....why should I buy anything but the 11.1v Super High Discharge Kokam? From what I understand from one of your posts...as long as i limit current even a small motor like on the gws lite stick could handle the 11.1v super high discharge Kokam? If the motor is only drawing 2 amps lets say, then why would 20C of continuous discharge be necessary? Do I need a special speed controller for the Kokam Super high discharge packs?

Thanks for your time and help.

Peter Simons

(in reply to Greg Covey)
       Post #: 30

RE: Got Kokams? - 12/12/2003 9:34:36 PM   
Greg Covey



Posts: 4450
Joined: 5/24/2003
From: Rochester, NY, USA
Status: offline 		Hi Peter,

Now I see the thread you mentioned.

Answered via e-mails.

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(in reply to pnsimons)
       Post #: 31

RE: Got Kokams? - 12/12/2003 9:40:00 PM   
Greg Covey



Posts: 4450
Joined: 5/24/2003
From: Rochester, NY, USA
Status: offline 		When it comes to those lighter than light aerobatic flyers like the new Fantastic Models AT-6 Texan from Hobby Lobby, you just can't beat a Kokam 340SHC pack!

Look for my review on the little AT-6 Texan soon.

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       Post #: 32

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