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Changing Battery Connectors, need some guidance please!

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Old 10-14-2014, 03:43 PM
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CastorTroy2150
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Default Changing Battery Connectors, need some guidance please!

I am not new to flying or electric flight, but I am new to changing connectors. Up till this point most my electric models have had stock batteries or batteriea with the same connectors. Bought a 50mm Viper EDF and the power connector is a JST two pin style. The batteries I ordered are Rhino 11.1v 40c 1050maH and have an XT50 connector or something. I've seen videos on people cutting off connectors and soldering on JST( or other connectors), but have one concern. The pre wired JST connectors have a wire gauge that is much smaller than the leads coming from the batteries I purchased. Isn't it kinda bad to shrink the gauge of the wire that much?


Also, on a side note, the stock batteries are 11.1v 3s 25c 850maH, how much higher of a ,"C" rate can I go without having an issue? For example, is a 35-40c battery going to be an issue? I thought not as my research seems to conclude that the motor will only draw as much as it needs anyway, and the C rating won't effect anything negatively. There is just so many different opinions it is hard to weed through the junk.....thanks in advance!
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Old 10-14-2014, 06:03 PM
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Dang, place is a ghost town nowadays.... Sad
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Old 10-14-2014, 07:22 PM
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It really depends on the current draw. No problem having a different wire size on the battery leads from the ESC provided that the smaller wire gauge is adequate for the current. If the wire gauge and the JST connector on you ESC is adequate for the motor's current draw, then you are safe replacing the battery connector too. Just don't use that battery connector on another model that has a higher draw.
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Old 10-22-2014, 10:55 AM
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Quote:
Originally Posted by CastorTroy2150 View Post
I am not new to flying or electric flight, but I am new to changing connectors. Up till this point most my electric models have had stock batteries or batteriea with the same connectors. Bought a 50mm Viper EDF and the power connector is a JST two pin style. The batteries I ordered are Rhino 11.1v 40c 1050maH and have an XT50 connector or something. I've seen videos on people cutting off connectors and soldering on JST( or other connectors), but have one concern. The pre wired JST connectors have a wire gauge that is much smaller than the leads coming from the batteries I purchased. Isn't it kinda bad to shrink the gauge of the wire that much?
My habit has been to standardize on one connector type and then change everything to that. For me it is the Dean Ultra Plug or what is sometimes called a T Plug. Good to up to 100 amps I believe. Everything I have gets that plug.

As for the wires. The size wire needed is determined by the motor/ESC. Your battery may be able to handle a lot more current than this plane needs so having thicker wire on the battery is not a problem.



Quote:
Originally Posted by CastorTroy2150 View Post
Also, on a side note, the stock batteries are 11.1v 3s 25c 850maH, how much higher of a ,"C" rate can I go without having an issue? For example, is a 35-40c battery going to be an issue? I thought not as my research seems to conclude that the motor will only draw as much as it needs anyway, and the C rating won't effect anything negatively. There is just so many different opinions it is hard to weed through the junk.....thanks in advance!
A higher C rating will never hurt your aircraft or its motor. The key is to make sure that the battery can put out enough amperage to satisfy the draw of the motor. So if your stock battery is an 850 25C pack that means that the most it can put out safely is 21.25 amps.

If, for example your plane is pulling 18 amps then the battery is being worked at 84% of this rated max. Not too bad but the battery is working to put out that amperage.

If you had an 850 65C pack then the battery is rated for 55.25 amps. If your motor is only pulling 18 amps then the battery is only working at 33% of its maximum. The battery is loafing.

The benefit of the higher C rated pack is since it is not working so hard the voltage will hold up better which means the prop will spin faster and you will probably get better performance from the plane just because you are using a higher C rated pack.

I try to make sure that my planes never draw more than 80% of the rated continuous amperage and if they are running around 60% that is even better.

In some respects the C rating is related to the internal resistance of the battery pack. The lower the internal resistance the faster it can deliver its power.

Hope that helps. This book will explain more.

EVERYTHING YOU WANTED TO KNOW ABOUT ELECTRIC POWERED FLIGHT
http://www.rcuniverse.com/forum/m_7100376/tm.htm
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