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sassypickins

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On the way to RTR I'll be picking up a 190w jtm190-72 mono panel, Midnite Solar Kid 30-amp mppt charge controller and 50' of cable w/mc4 connectors for a 20'+ portable run.  This will be my first battery charging system.  I may add the van alternator later, but that's another day.

The recommendation I'm getting is 10-gauge cable for my panel to controller.   I am considering 8-gauge instead.  I saw a video where someone switched his 10 out to 8 and measured almost double output increase.  Here's what I was told:  5.2 amp lmp, 36.5v vmp panel using 10-gauge over 25' results in a .88v drop, and with 8-gauge .55v drop, so supposedly not worth spending the money on 8-gauge.  Thoughts?  Maybe the video guy's system was so big it was worth it for him.

Batteries are 2 new 6v T105's @ 225Ah.

I have some 4 gauge wire.  Can I use it between the controller and the battery bank?  I'll get those professionally crimped.

Is a 40 amp in-line fuse block/fuse correct between controller and battery bank (1' to 2' run)?  

Do I need to ground the panel? 

Twist the cabling?

Anything I'm missing on this side?

I'll ask about the stuff on the other side of the battery bank next.

Thank you so much.

Sassy

ps.  For now, my usage looks to be around 30 amps over 24 hours and nothing big, only phones, tablet, laptops, fan, maybe a few small led lights (but I have my lovely Luci solar lights - I love them!) On my wish list is to upgrade this system later for a 12v compressor fridge, which will about double the amperage, I think.
 
I have the MidNite Kid 30A MPPT controller.  The lugs to put the cable in on the controller will only accept 10 Ga cable  :dodgy:   I was going to connect everything with 6 Ga cable of which I have a bunch. :huh:  I guess strands could be removed at just the ends so it would fit ut the run to your battery sounds short.  My remote set will be at the end of a 10 Ga 50 ft extension cord.  My first set is on the roof.  A 30 amp circuit breaker (or 30 amp fuse) should be on the input from the panels and one close to the battery.

No earth grounding necessary as this is a mobile install, not S&B.  Your ground will be the negative cable by default.  You may want to tape those two cable together to help with managing them and I guess you could twist them.  Twisting and a little tape both might be the way to go since these are separate wires.

You want to put your fuse close to the battery and 10 Ga cable is only rated to carry 30 amps.  Connect your batteries together with the 4 Ga wire and the battery negative to the frame ground with 4 Ga cable.

You are putting together a good starter kit although that panel sounds really large for a remote panel. :p

When you get to the RTR, there will be plenty of help (me included).  I won't be getting there until late on the 5th or early on the 6th.  Hoping for the 5th.
 
The Solar seminar is on the 9th, 10 AM, and I should be there by then...

I will keep going until the Chili is ready!
 
Thanks, Brian. Yeah, that panel weighs 34 lbs. I'm going to experiment wheeling it around with a little cart. I dont think storing it in the van will be a problem but time will tell.
I'm tempted to go with 8 and pare it down at the controller, especially if it will allow me to upgrade some later.
Chili!!!
 
You don't have to take people words for it, you can verify it yourself with this volate drop calculator:
http://www.calculator.net/voltage-d...ce=20&distanceunit=feet&amperes=5.5&x=52&y=11

Here's what it worked out to be and to my mind that's fine and I'd go with 10 gauge:


Voltage-Drop-10-gauge.jpg
 
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