400amp 2ga vs 500amp 4ga

[barcloverranch]

Hello everyone,

I am about to convert my 86 EzGo to a solid state control system and I have a question.

Would a cart benefit more from a 400 amp controller with 2ga cables, or a 500 amp controller with 4ga cables?

Or would it really be worth the while to splurge for the 500 amp controller and 2ga cables?

Thanks everyone,
Josh

[scottyb]

Originally Posted by barcloverranch

Hello everyone,

I am about to convert my 86 EzGo to a solid state control system and I have a question.

Would a cart benefit more from a 400 amp controller with 2ga cables, or a 500 amp controller with 4ga cables?

Or would it really be worth the while to splurge for the 500 amp controller and 2ga cables?

Thanks everyone,
Josh

A 400 amp control on 36v would benefit from 2g cables as there is actually more amperage consumed at the lower voltage for the motor to produce the same amount of power. Higher voltage = lower amperage.
So 36 or 48 volts is an important part of this question... 500 amps is a 25% in crease in available amperage from a 400, amperage = torque.
An increase in voltage from 36 to 48 volts will increase the speed and torque from your stock motor by 30-33%.
I don't know if I answered your question or just muddied the waters.

[barcloverranch]

Okay so I understand most of what you said, as I increase the amperage I increase the torque.

I don't plan to upgrade to 48v anytime soon, I will just stick with 36v.

But I am still unclear about the answer to the question of 400 amp with 2ga cables vs 500 amp with 4ga cables? Which setup would provide more torque?

And would 500 amp with 2ga cables really be that much better than either of these other two setups? You don't have to crunch any numbers or anything I was just wondering in your opinion which would provide the best bang for the buck.

Sorry if I'm being difficult,
Josh

[JohnnieB]

Crunching numbers is about the only way to illustrate the difference between 2Ga and 4Ga cables, other than installing a set.

I'm guessing your cart will take about 30' of cable and 2Ga is 0.0001563 Ohms per foot while 4Ga is 0.0002485 Ohms per foot.

At 500A:
You will loose 2.34V with 2Ga Cables regardless of battery pack voltage.
You will loose 3.72V with 4Ga Cables regardless of battery pack voltage.

At 400A:
You will loose 1.87V with 2Ga Cables regardless of battery pack voltage.
You will loose 2.98V with 4Ga Cables regardless of battery pack voltage.

There are tons of variables that determine the actual loss in performance caused by the 1.38V (@ 500A) or 1.11V (@400A) cable loss, but it should be obvious that 2Ga cable are more efficient than 4Ga, and a little research on-line will tell you the best 2Ga cables available (IMHO) are only about $30 more than the best 4Ga.

[barcloverranch]

Okay awesome. I will go ahead and fork out the money for 2ga cables, thanks for the thorough explanation

[scottyb]

I agree, what he said without all the little numbers after the dot

[Russ/TN]

What kind of motor will you use?
As far as I understand it. 500 Amps would a little too much for a stock motor.
You guys please correct me if I am wrong.

[barcloverranch]

Oh yeah I was planning on using the stock motor. Somebody please let me know if 500 amp will be too much

[scottyb]

500 amps is a lot of amperage. It needs to be used responsibly. I have been schooling my customers on using 500 amps with a stock motor for 2 years now, not one of them has come back to me with a burnt up motor. I personally ran a 89 CC stock 36v motor on 650a and 48v for 1.5 years then sold it and it never came back... so I think it is safe to say 500 amps can be used on a stock motor with a little common sense.

[yurtle]

I ran my stock 36 volt motor on 48 volts at 400 amps while monitoring temperature, then I cranked it up to 500 amps and it didn't run much hotter given my hills and round trip distance. YMMV, but heat is your enemy. I bought an Alltrax Ex-Ray to monitor temp, but a handheld temp meter will work.

Most motors are wound with 180°C insulation, but you have brushes and a bearing to worry about.