Twin motors, twin batteries, twin problems

Mauihiflyer · Nov 03, 2009, 02:56 PM

Here's the problem. I have a Hangar 9 B-25 with two E-flite 46 motors pulling about 47 amps each at full static power. That's 94 amps total. I set up two 4 cell 5000 ma. batteries into two Deans parallel plugs so the the current from the two batteries is pooled together and then re-split to the two motors (see photo). This allows both motors to have equal voltage and amps all the time, and should prevent one motor from running out of power before the other. It also aids in both motors running at the same speed (harmonics). The problem is that further research in to the Deans parallel plugs indicate that they are limited to 50 -60 amps, meaning that I am not getting full power, or they are going to get hot. Anyone have any ideas of a different parallel hook up that will supply full power.

everydayflyer · Nov 03, 2009, 03:06 PM

Why not go to 5 mm bullet connections?

Charles

Mauihiflyer · Nov 03, 2009, 03:20 PM

Quote:

Originally Posted by everydayflyer

Why not go to 5 mm bullet connections?

Charles

Explain how to interconnect them like the above photo

Ira NZ · Nov 04, 2009, 02:38 AM

Quote:

Originally Posted by Mauihiflyer

The problem is that further research in to the Deans parallel plugs indicate that they are limited to 50 -60 amps, meaning that I am not getting full power, or they are going to get hot. Anyone have any ideas of a different parallel hook up that will supply full power.

No reason you need to them paralleled through a deans. You could have each battery connected to a Deans but the actual parallel point be simply the wires twisted together and soldered.

abenn · Nov 04, 2009, 02:58 AM

Ira NZ has beaten me to it. If you do it his way, each Deans will be passing only 47 amps or thereabouts, and the only part of the circuit that'll be taking 94 amps is the wire parallel connection with the soldered joint.

Mauihiflyer · Nov 04, 2009, 01:44 PM

Quote:

Originally Posted by Ira NZ

No reason you need to them paralleled through a deans. You could have each battery connected to a Deans but the actual parallel point be simply the wires twisted together and soldered.

Though I agree that that might work, I lose the flexibility of two seperate batteries tht I use in other aircraft.

Hughes500Bob · Nov 04, 2009, 01:58 PM

http://www.castlecreations.com/media...03-Mar2006.pdf
Pages 2 and 3 are great!

http://www.robotmarketplace.com/prod...onnectors.html

Note what is says for the Ultra Plug "A tight-fitting and small-size (13 x 8mm) connector with very low loss. Rated number 1 by R/C Car Action, The Ultra Plug actually has less resistance, including the solder joints, than an equivalent length piece of 12 gauge wire."

IMO Use what you have or go for a bigger connector taking up a lot more room.

Bob

Ira NZ · Nov 04, 2009, 02:01 PM

Uhhh...No you don't.
Battery-DeansDeans-\_/--ESC
Battery-DeansDeans-/ \--ESC

Assuming that worked right, it has no effect on the batteries. It ties together after the deans you use to plug into the system and each deans will only be seeing about 47 amps and the point both sides are wired together after the deans will be the only place seeing 94 amps.

lyclyc · Nov 04, 2009, 03:28 PM

off topic question..
is it important to run it in harmonic?
if you run it separately, and in case one battery run out of juice, you still have another motor running?

Mauihiflyer · Nov 04, 2009, 04:42 PM

Loss of one motor in a twin engine RC plane is a MAJOR challenge to maintain control.

realtimerecon · Nov 04, 2009, 04:45 PM

Loss of 1 Eng.on a C-47 (full sized) and it will fly for ever.
Been there did that twice

...RTR

Mauihiflyer · Nov 04, 2009, 04:49 PM

Lost a few in full scale also. RC is quite a bit different. Not sitting in the cockpit gives a different perspective.

Mauihiflyer · Nov 04, 2009, 04:52 PM

[quote=Ira NZ;13504695]Uhhh...No you don't.
Battery-DeansDeans-\_/--ESC
Battery-DeansDeans-/ \--ESC

I'm having a visualization problem. Can you explain further?

Ira NZ · Nov 04, 2009, 10:17 PM

Two Batteries females deans plug into the two male wire harness deans. You have two negatives coming off those. You also have two negatives going to each ESC. You take the two negatives come from the male deans, you twist them all together with the two negatives going to the ESCs and solder them together and insulate as appropriate. It's like a big X.

Then repeat for the positive wires.

abenn · Nov 05, 2009, 03:17 AM

Does this help? The only bit taking the full 94 amps is the two wires between the soldered connections. They can be as long* or as short as you need.

* Edit: Don't make them too long, otherwise you have other problems, which are covered in other threads about "long battery leads".

Nov 03, 2009, 02:56 PM	#1
Mauihiflyer Bird of Time Join Date: Sep 2003 Location: Maui Posts: 113	Twin motors, twin batteries, twin problems Here's the problem. I have a Hangar 9 B-25 with two E-flite 46 motors pulling about 47 amps each at full static power. That's 94 amps total. I set up two 4 cell 5000 ma. batteries into two Deans parallel plugs so the the current from the two batteries is pooled together and then re-split to the two motors (see photo). This allows both motors to have equal voltage and amps all the time, and should prevent one motor from running out of power before the other. It also aids in both motors running at the same speed (harmonics). The problem is that further research in to the Deans parallel plugs indicate that they are limited to 50 -60 amps, meaning that I am not getting full power, or they are going to get hot. Anyone have any ideas of a different parallel hook up that will supply full power. Attached Thumbnails 113.1 KB · Views: 108

Nov 04, 2009, 04:45 PM	#11
realtimerecon Real Time Recon Join Date: Jan 2007 Location: SML. VA Posts: 6,115	Loss of 1 Eng.on a C-47 (full sized) and it will fly for ever. Been there did that twice...RTR

Nov 05, 2009, 03:17 AM	#15
abenn Registered User Join Date: Jul 2004 Location: Letchworth, Great Britain (UK) Posts: 5,683	Does this help? The only bit taking the full 94 amps is the two wires between the soldered connections. They can be as long* or as short as you need. * Edit: Don't make them too long, otherwise you have other problems, which are covered in other threads about "long battery leads". Attached Thumbnails 34.9 KB · Views: 21 Last edited by abenn; Nov 05, 2009 at 05:48 AM. Reason: Clarification

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Nov 03, 2009, 03:06 PM	#2
everydayflyer Southern Pride Join Date: Oct 2004 Location: Haralson County GA. USA Posts: 24,269	Why not go to 5 mm bullet connections? Charles

Nov 04, 2009, 02:58 AM	#5
abenn Registered User Join Date: Jul 2004 Location: Letchworth, Great Britain (UK) Posts: 5,683	Ira NZ has beaten me to it. If you do it his way, each Deans will be passing only 47 amps or thereabouts, and the only part of the circuit that'll be taking 94 amps is the wire parallel connection with the soldered joint.

Nov 04, 2009, 01:58 PM	#7
Hughes500Bob Retired CFI Helicopter Join Date: Jun 2007 Location: Southeast PA Posts: 537	http://www.castlecreations.com/media...03-Mar2006.pdf Pages 2 and 3 are great! http://www.robotmarketplace.com/prod...onnectors.html Note what is says for the Ultra Plug "A tight-fitting and small-size (13 x 8mm) connector with very low loss. Rated number 1 by R/C Car Action, The Ultra Plug actually has less resistance, including the solder joints, than an equivalent length piece of 12 gauge wire." IMO Use what you have or go for a bigger connector taking up a lot more room. Bob

Nov 04, 2009, 02:01 PM	#8
Ira NZ Bombs away! Err...landing Join Date: Apr 2006 Location: Upper Hutt, New Zealand Posts: 1,542	Uhhh...No you don't. Battery-DeansDeans-\_/--ESC Battery-DeansDeans-/ \--ESC Assuming that worked right, it has no effect on the batteries. It ties together after the deans you use to plug into the system and each deans will only be seeing about 47 amps and the point both sides are wired together after the deans will be the only place seeing 94 amps.

Nov 04, 2009, 03:28 PM	#9
lyclyc Pirouetting flip master Join Date: Jul 2007 Location: Malaysia Posts: 612	off topic question.. is it important to run it in harmonic? if you run it separately, and in case one battery run out of juice, you still have another motor running?

Nov 04, 2009, 04:42 PM	#10
Mauihiflyer Bird of Time Join Date: Sep 2003 Location: Maui Posts: 113	Loss of one motor in a twin engine RC plane is a MAJOR challenge to maintain control.

Nov 04, 2009, 04:49 PM	#12
Mauihiflyer Bird of Time Join Date: Sep 2003 Location: Maui Posts: 113	Lost a few in full scale also. RC is quite a bit different. Not sitting in the cockpit gives a different perspective.

Nov 04, 2009, 04:52 PM	#13
Mauihiflyer Bird of Time Join Date: Sep 2003 Location: Maui Posts: 113	[quote=Ira NZ;13504695]Uhhh...No you don't. Battery-DeansDeans-\_/--ESC Battery-DeansDeans-/ \--ESC I'm having a visualization problem. Can you explain further?

Nov 04, 2009, 10:17 PM	#14
Ira NZ Bombs away! Err...landing Join Date: Apr 2006 Location: Upper Hutt, New Zealand Posts: 1,542	Two Batteries females deans plug into the two male wire harness deans. You have two negatives coming off those. You also have two negatives going to each ESC. You take the two negatives come from the male deans, you twist them all together with the two negatives going to the ESCs and solder them together and insulate as appropriate. It's like a big X. Then repeat for the positive wires.