Wire length

[ChillnGrill]

Help. Can I use 20' of 4/0 from my batteries to my 18kpv. The problem is I had to put the 18kpv on another wall. I have my bank of 6 x lifepower4 in the area closet to my eg4 6500's and have 10' of cable to the bus bars now. I would like to just add another 10' from bus bar to 18kpv. Will the 20' of cable cause a problem? Hard to relocate the batteries closer due to weight and room ( small shed)

 

[kendive]

Voltage Drop Calculator

This free voltage drop calculator estimates the voltage drop of an electrical circuit based on the wire size, distance, and anticipated load current.

www.calculator.net

 

[cs1234]

Dangit @kendive, you beat me to it!

 

[ChillnGrill]

In the manual it says 10’ max on 4/0 wire for the batteries. I want to go 20’ and want to know if it will cause a problem. 10’ from the rack of 6 batteries to bus bar then another 10’ to the inverter.

 

[GuyG]

A couple of things to keep in mind: First, if your battery is 20 feet from the inverter, you are looking at a 40’ round trip. That’s the figure to use for your calculations. The other inputs are of course 48 volts and the total amperage/current. I think that’s 250 amps for your inverter.

Second, voltage drop is a lot more important in a DC battery context than in an AC situation. A couple of volts lost in a 120-volt ac circuit is no big deal; a 2-volt drop from 51.2 to 49.2 in a battery charger is significant. Use a high quality, high copper content cable, preferably rated at least at 105 C if you can.

This might be a better calculator to use since it’s specific to dc battery applications:

Interactive Wire Size Calculator

Battery Chargers, Inverters, Solar Components, and Wiring Supplies for Boats, RVs, and Off-Grid Applications.

baymarinesupply.com

Good luck and let us know how it works out.