View Full Version : Razor batt cable length
busted blade
02-05-2007, 09:20 PM
i want to turn my batteries around because i dont like the the cables being at the back. it clutters up the area which is already cluttered and looks like poop.if i do this the longest cable (from where it exits the battery to where it enters the esc) will be about 12 inches. if i face the packs as the manual shows the longest cable will be 7 inches. the thought popped in my head about the cable length/resistance issue. so im askin, is it moot or should i keep them as short as possible? i will still be able to unplug the packs, wires facing forward, with canopy on so thats no issue
WillJames
02-06-2007, 03:07 AM
Keep the leads as short as you can from what I understand.
I have been advised from Electric flight mag articles in the past not to go any longer than 6 in (150mm) on your battery leads. Most battery packs come with ~4 inch leads (100mm) so I doubt that 7 inches is required anyway. I certainly would not go to 12 inches if I were you.
Cheers,
Tom C
OICU812
02-06-2007, 02:45 PM
I think the battery wires themselves should be within reason, however making say a series plug or cord between the batteries and esc should not be an issue with abit of length, I have a extension to run my esc on back of a eraptor it must be 7-9 inches somewhere and on my Ion I had I had a series plug that must have made it 7 inches for sure on top of battery wire length, and worked good. However that being said it does make sense to keep it shorter "if you can". In my cases I was not able to.
DavidH
02-06-2007, 05:48 PM
Yes always keep the wires as short as possible. Wire creates resistance. That is why you see the RC car racers, keep the battery wires to the minimum and also hard solder them to the batteries. No plugs for them.
David
The mag article I read (albeit a few years ago) stated that the problem with excessively long battery leads, with our high voltage packs, is that the wires themselves can start acting like capacitors and can feed back-emf into the esc. This apparently could cause problems with the esc. Their recommendations were to try to limit the leads to 6 inches max.
Interestingly, the article said you could safely run fairly long (up to ~12 inches) on the motor/esc leads. So, for example, if you had a flying boat with a motor mounted on a tall wing pylon, you were better to keep the esc close to your batteries and extend the esc/motor wires.
Maybe with more modern esc's and their pretty big capacitors this is not much of a issue anymore. If you need to extend any of these leads beyond 6 inches, it might be a good idea to contact your esc maufactuer's tech support and ask them their opinion.
Cheers,
Tom C
jrohland
02-07-2007, 08:01 AM
...Interestingly, the article said you could safely run fairly long (up to ~12 inches) on the motor/esc leads.DC does not like to travel long distances. However, the power from the ESC to the motor is AC. It should be fine to use longer motor leads. Move the ESC closer to the batteries, if you can.
If you really need to run long power (battery) leads, lower the gauge of the leads. I.E., use thicker wire. That is sub-optimal but, it is better than melting your power leads.
jrohland