Wire Size Question

[BurbMan]

After weighing the battery options and re-assessing my available space. I found I have a nice basement space between the landing gear that has a heavy duty steel plate floor (like 1/8" thick steel). So the plan is 4-6v GC2's (these Duracells) in a storage tote plumbed to the existing fresh air vent.

Converter/charger is a Progressive Dynamics PD-9260C located about 6' away from the batteries and wired in with what looks to be #6 wire. With a small 500w inverter on a single-circuit transfer switch, will I be OK wiring the batteries in with #6? Or should I go to a lower gauge like #4?

[Gdetrailer]

dougrainer wrote:

Gdetrailer wrote:

wa8yxm wrote:
I would not upgrade the wire.. #6 can easily handle 60 amps
As was noted 4ga you might charge a bit faster but frankly the increase won't likely be noticable.

While technically correct, myself, I like to error on the plus side of things. #6 will rated to handle 60A it isn't the amps that is the issue, it is voltage drop. I like to reduce the voltage drop as much as possible when dealing with 12V systems.

It is for that reason I used 1/0 wire between batteries and converter even though my converter is less than 6ft for both pos and neg. Batteries charge much faster than the old setup which had the converter located 15ft away from the batteries and they used 8ga wire..

If the OP has heavier wire on hand and it is easy to run new wire, I say go for it..

It is ALWAYS better to wire any Inverter direct to the Battery. Your set up, as noted, the 6 Gauge is more than enough from the Converter to the Battery. The heavier the gauge from the battery to the Inverter is best. Doug

Doug, I WAS talking about my setup which I did use 1/0 between the CONVERTER and battery. I also did use 1/0 between battery and INVERTER.

I had to buy a minimum quantity of 20 ft of red and 20ft of black 1/0 extra flex. So, after wiring my inverter, I had lots of 1/0 leftover and pondered the idea of making some super duty jumper cables OR use the leftovers to upgrade the converter to battery wiring.

Basically ended up with a bonus of maxing out my PD9160 charging capacity and the PD9160 with CW is very content to drop into storage mode when not in use.. Result is only needing to check the battery water level once a yr and water use is about 18 oz of water per yr across all cells.. I call it a win.

In the case of the OPs post, what they have will do, but if they have something heavier laying around with nothing to do they can squeeze the max performance out of their PD..

[Durb]

If voltage drop is a major concern, you may want to reconsider lithium ion batteries. Maximum output voltage of a GC battery is 6.37 volts. Wired in series will give you 12.75 volts. The output voltage will drop severely with use and lower state of charge.

Fully charged, a lithium battery is a 14.4 volts (13% increase) and will keep 12.9 volts all the way down to 20% charge; still better than the GC batteries at peak.

I put a single lithium battery in my fiver which is fine for how I use it. All components work better, Landing gear is faster, electric slides are faster and consistent, electric dump valves work every time, some lights are brighter. 2 years now and no damage to any components from higher voltage.

[dougrainer]

Gdetrailer wrote:

wa8yxm wrote:
I would not upgrade the wire.. #6 can easily handle 60 amps
As was noted 4ga you might charge a bit faster but frankly the increase won't likely be noticable.

While technically correct, myself, I like to error on the plus side of things. #6 will rated to handle 60A it isn't the amps that is the issue, it is voltage drop. I like to reduce the voltage drop as much as possible when dealing with 12V systems.

It is for that reason I used 1/0 wire between batteries and converter even though my converter is less than 6ft for both pos and neg. Batteries charge much faster than the old setup which had the converter located 15ft away from the batteries and they used 8ga wire..

If the OP has heavier wire on hand and it is easy to run new wire, I say go for it..

It is ALWAYS better to wire any Inverter direct to the Battery. Your set up, as noted, the 6 Gauge is more than enough from the Converter to the Battery. The heavier the gauge from the battery to the Inverter is best. Doug

[Gdetrailer]

wa8yxm wrote:
I would not upgrade the wire.. #6 can easily handle 60 amps
As was noted 4ga you might charge a bit faster but frankly the increase won't likely be noticable.

While technically correct, myself, I like to error on the plus side of things. #6 will rated to handle 60A it isn't the amps that is the issue, it is voltage drop. I like to reduce the voltage drop as much as possible when dealing with 12V systems.

It is for that reason I used 1/0 wire between batteries and converter even though my converter is less than 6ft for both pos and neg. Batteries charge much faster than the old setup which had the converter located 15ft away from the batteries and they used 8ga wire..

If the OP has heavier wire on hand and it is easy to run new wire, I say go for it..

[wa8yxm]

I would not upgrade the wire.. #6 can easily handle 60 amps
As was noted 4ga you might charge a bit faster but frankly the increase won't likely be noticable.

[Bobbo]

The #6 will be safe. However, the #4 will give you less voltage drop, therefore, better service.

The smaller the number, the larger the wire diameter, the less voltage drop.

I just went to a voltage drop calculator. A #6 wire 6' long carrying 13v and 60 amps has 2.32% voltage drop. Increasing that wire to #4 reduces the voltage drop to 1.47%.