Battery charging wire size

[Guest]

Howard,

Thank you for the drawing. It appears the WFCO can be left in place as a backup. Would there be any info on the AC side? Thinking that just pulling the AC breaker on the WFCO may be all that's needed in using an alternate charger in the passthrough.

By the way, you being a pioneer on these systems has in a very positive way convinced me to go in this direction. Plus you worked on jets. That's all I need.

Jim

[howson]

Howard,

Thank you for the drawing. It appears the WFCO can be left in place as a backup. Would there be any info on the AC side? Thinking that just pulling the AC breaker on the WFCO may be all that's needed in using an alternate charger in the passthrough.

By the way, you being a pioneer on these systems has in a very positive way convinced me to go in this direction. Plus you worked on jets. That's all I need.

Jim

The WFCO in my 315RLTS has a power cord with a standard NEMA 115V plug. The Distribution Center has an outlet right on the back. I could throw the breaker (obviously) or just unplug the converter. Nothing else is on that circuit anyway, so neither way has a benefit unless I wanted to plug something into the (now free) outlet.

How is your Imagine configured?

[Guest]

Howard,

I do not know precisely know how my Imagine is configured (too cold out there) but from my understanding in how it functions, such as not charging with the battery switch off, killing all function with the battery switch off (misbuild?) and that 12V power is supplied by the battery and/or the converter tells me they are directly connected to the bus bar as long as the switch in the pass through in closed. If my converter is plugged in via an electrical plug, this would be ideal.

You did bring up another important item.... whether I have a GFCI in the pass through and how this would function with the charger. I do believe I have outlets in the pass through on the GFCI circuit and this needs to be sorted out. Worse case, I can tap into the bedroom outlets which are not on the GFCI circuit. Max input current for my charger is 7.5 amps. I plan on adjusting it to consume 5.0 amps AC.

Jim

[Oregon Fun-Guy]

Howard,

I do not know precisely know how my Imagine is configured (too cold out there) but from my understanding in how it functions, such as not charging with the battery switch off, killing all function with the battery switch off (misbuild?) and that 12V power is supplied by the battery and/or the converter tells me they are directly connected to the bus bar as long as the switch in the pass through in closed. If my converter is plugged in via an electrical plug, this would be ideal.

You did bring up another important item.... whether I have a GFCI in the pass through and how this would function with the charger. I do believe I have outlets in the pass through on the GFCI circuit and this needs to be sorted out. Worse case, I can tap into the bedroom outlets which are not on the GFCI circuit. Max input current for my charger is 7.5 amps. I plan on adjusting it to consume 5.0 amps AC.

Jim

I would guess your Imagine is set up much the same way as mine. I have two outlets in my pass-thru, one on either side. They are both connected on the same 120v circuit. Your circuit from the battery to the fuse panels is a positive wire directly wired from the battery to the fuse panel on the 12v side. The negative wire on the fuse panel is connected to a busbar with the rest of the 12v negative wires. The battery is wired on the negative side to the frame.

I've seen the pictures of your model of trailer. Where is the fuse panel located? I am curious to know how far it is from the fuse panel to the batteries.

[Guest]

Norm,

My fuse panel is below the TV at the floor and is approximately 20ft from the battery.

Jim

[Oregon Fun-Guy]

Norm,

My fuse panel is below the TV at the floor and is approximately 20ft from the battery.

Jim

Jim, I found that your trailer is about three feet longer than mine. The only real difference in layout is that your refrigerator is on the opposite side from mine between the stove and the pantry. That makes up the three foot difference.

I got most of my parts and started working on the wires today. The biggest thing I got done was to run the positive 4 awg wire from just behind the pass-thru to the distribution panel. I pushed a 10 ft long 1/2" pvc pipe through the holes in the frame pieces. There were some obstacles, but I was able to drop the propane hoses and the bottom cover so I could work the pvc pipe back to the hole in the floor behind the distribution panel. After this I pushed the new 4 gauge wire back through the pipe. I'll find out tomorrow whether the new wire will directly connect to the distribution panel. The extra three feet distance you have to go means you have to have a longer pipe but it is doable. This biggest problem I see now is that it is difficult to get my hands under the floor to change the ground wire to the size I want. I guess thats what saws were made for, to make bigger holes.

I found you have to add another 14 - 16 feet to the length of the converter to battery wire to account for connection to the battery disconnect switch. That makes makes for a 34 foot wire for you and and a 31 foot wire for me. This makes for a minimum of a 16 - 18% voltage drop or 1.5 to 2 volts. This is why we have been subjected to slow battery charging.

Norm

[Guest]

Norm,

You've come up with a very clever idea in pushing a piece of PCV through with your wire.

Your probably aware of an ampacity chart which I've found to be helpful in sizing up wire based on temperature, copper connectors and total amperage.

Here are a couple examples.

http://solar-trap.com/wp-content/upl...GaugeChart.jpg


https://www.bing.com/images/search?v...x=0&ajaxhist=0

I've planned on mounting my 60 amp Progressive Dynamics unit in the passthrough and running 4 AWG right to the busbars on the frame. From there I will run 4 AWG to the battery. There are some other components that will be inline such as a battery shunt and some resettable breakers. One item Howard brought up was whether the Progressive Dynamics unit can be plugged into a GFCI outlet and according to their manual it can. So just need to find the best location as to not have items getting in contact with the terminals. This will most likely be on the aluminum frame in the ceiling of the passthrough.

Jim

[Oregon Fun-Guy]

Norm,

You've come up with a very clever idea in pushing a piece of PCV through with your wire.

Your probably aware of an ampacity chart which I've found to be helpful in sizing up wire based on temperature, copper connectors and total amperage.

Here are a couple examples.

http://solar-trap.com/wp-content/upl...GaugeChart.jpg


https://www.bing.com/images/search?v...x=0&ajaxhist=0

I've planned on mounting my 60 amp Progressive Dynamics unit in the passthrough and running 4 AWG right to the busbars on the frame. From there I will run 4 AWG to the battery. There are some other components that will be inline such as a battery shunt and some resettable breakers. One item Howard brought up was whether the Progressive Dynamics unit can be plugged into a GFCI outlet and according to their manual it can. So just need to find the best location as to not have items getting in contact with the terminals. This will most likely be on the aluminum frame in the ceiling of the passthrough.

Jim

Yes, I've seen the ampacity charts. I'm also seeing more than one way to skin this cat, both the way you going or replacing the WFCO converter with the converter part of the PD either 55 or 60 amp in the distribution box. The 4 awg wire and a shorter run through the trailer should allow the batteries to charge at a higher power and charge completely. I've also read some about the neutral side of the system. I've read that the ground wire attached to the frame can use 6 awg instead of 4 awg with the same result. This will help me with the neutral busbar behind the distribution panel. This busbar uses the (currently) 8 awg wire from the distribution box wire to join with 8 or so smaller neutral wires and then continue onto the frame ground with a single 8 awg wire. The holes in the busbar aren't big enough for the 4 awg, but they will take a 6 awg. (I read that this was ok.) This way I make sure the system of neutral wires is adequately grounded. The other thing that I accomplish is to keep the positive wire inside the pvc so the 4 awg wire is protected. The whole neutral treatment may change if I change my mind.

Overall, I will be shortening the transmission wires by about 17 or 18 feet because I will also be moving my battery disconnect switch.

If we pull this whole thing off will we earn our junior E.E. badge?

[Country Campers]

Oregon Fun-Guy

I was gong to mention to move the battery disconnect switch but see you have already thought of that. I have relocated mine and removed about 6 feet of wire out of the equation. Seems you are well on your way to a better charging and better usage of the battery power.

Brian

[Guest]

Its looking like GDRV should be considering a better location for the power distribution panel or as Norm is doing, to install heavier wire on the battery feed circuit. It will be interesting to see how the WFCO unit charges those big 6V batteries after the improvements.

Jim

[howson]

Its looking like GDRV should be considering a better location for the power distribution panel or as Norm is doing, to install heavier wire on the battery feed circuit. It will be interesting to see how the WFCO unit charges those big 6V batteries after the improvements.

Jim

But...as we know from Oregon Fun-Guy 's thread GD is actually going the other way--8ga in his unit. https://gdrvowners.com/forum/operati...ging-wire-size

The reality is the WFCO spends the majority of time in Absorption mode. If you remember the AMSolar video, that's equivalent to small sips of brewsky. In other words, it operates for long periods of time at a low voltage/current level, thus (educated speculation) a smaller charging wire to the battery is justified.

I AM NOT defending the 8ga or even the (former) 6ga. What I can confidently state is if an owner decides to upgrade their converter, they should definitely consider upgrading their wiring, too. Especially if going to a lithium battery as those batteries will suck down power (almost) as fast as you can send it to them. A lithium WFCO converter connected to a Battle Born over 8ga wire...bad...as in "fire potential".

Hopefully the real electricians on this forum will chime in with their .02.

[Guest]

Howard,

You bring up some good points. For my rig, I have monitored my battery very carefully and never discharged below 12.0V. However, at 12.0V, I've never seen my WFCO charger go into bulk mode so the current going into the battery was always at 10amp or lower. This took 4-5 hours to charge the battery to 80% while running my generator. From the ampacity chart, 8 AWG would be borderline too small for bulk mode charging IMO. If the converter is upgraded to a higher capacity unit, the wiring MUST be swapped out to a heavier gauge or the converter/charger moved closer to the battery with a dedicated charge circuit. This is the route I'm taking with 4 AWG. Electricians or EE input is always valuable and welcome.

Jim

[Oregon Fun-Guy]

@MidwestCamper, @howson, @Country Campers, One more point that should be made is that slow-sipping does not always treat the battery for its longest longevity. Batteries need a periodic increase of higher power to undo some or maybe all of the sulfication caused by the constant trickle charging of the battery. This was never going to happen with the combination of trickle charge and voltage drop caused by the smaller, 8 AWG, transmission wire. If I were to drink an adult beverage by sipping all day and night through a small straw, I wouldn't live long either.

BTW you guys sure get up early.