new R-Pod owner

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   Yes my system is a 12v 100w with a 20 amp pwm controller.  It came pre wired supposedly, so will see if I want to add a larger/longer wires.  I haven’t even opened the box from amazon yet, but hope to at least look at it tomorrow. 

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Brent S Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 25 Sep 2018 Location: SE USA Online Status: Offline Posts: 21	Topic: new R-Pod owner Posted: 26 Sep 2018 at 2:40pm
	Yes my system is a 12v 100w with a 20 amp pwm controller. It came pre wired supposedly, so will see if I want to add a larger/longer wires. I haven’t even opened the box from amazon yet, but hope to at least look at it tomorrow.

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 26 Sep 2018 at 2:33pm
	Yeah, my buddy at Ameresco designed some in the 120-150W range at 24V. A couple other PV companies have them too. Pretty specialized product though, most companies are doing what you're doing now and using the standard resi or commercial modules which can be bought for less than $0.50/watt. I don't think the big modules are impractical if you roof mount them and don't try to move them around. Lots of RV'ers do that now. I'm too lazy to move them around anyway. The 72 cell ones are about 77-78 inches long by 39-40 wide. rPods are about 77-78 inches wide. I plan to mount 3 across on standoffs on my 179 above the roof after I yank off that POS roof air and replace it with an efficient and quiet mini split and yank off the TV antenna which I never use. That'll give me about 1050 nominal watts and the air gap will keep the PV array and rPod cooler too. But like I said, most people would think I'm crazy.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

GlueGuy Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 15 May 2017 Location: N. California Online Status: Offline Posts: 2660	Posted: 26 Sep 2018 at 1:28pm
	I have a couple modules in the garage that are 150 watts each with OCV of 37 volts. They were meant for off-grid applications of 24 or 48 volts depending. The newer ones we've been using for several years now are in the 250-350 watt range, and they are quite a lot larger; they would be very impractical for an R-pod solar system. With newer controllers they can be either off-grid or grid-tie. Sure can cook though!
	bp 2017 R-Pod 179 Hood River 2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 26 Sep 2018 at 1:17pm
	GlueGuy, Brent S has already bought a 100W module and controller, so I'm assuming that's going to be a 12V module and a PWM controller. There are a couple of higher voltage 120W modules out there but they're rare because they have to use cut cells, and I haven't seen a high voltage one at 100W for awhile. The ones you're using with Voc in the 35-40V range are probably going to be 60 cell residential grid tie modules or maybe 72 cell commercial project modules with 250-400W ratings. Those plus an MPPT controller are a great choice if you need that much solar charging. Turns out the length of the 72 cell modules is almost exactly the same as the width of an rPod so my plan is to mount those edge to edge on mine. But I'm trying to run my air conditioner from them, which most folks will think is crazy... Brent S, as GlueGuy says you can mount your controller either at the solar module or at the battery, or as many folks do, in a compartment and then run over to the battery. Since its all operating at 12V the voltage drops will be the same either way in this case. The size solar panel you bought is fine and meets most rPod folks solar charging needs, not counting any big AC loads like your microwave or air conditioner. Once you use it and the trailer a few times you'll get a good idea what your actual needs are.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 26 Sep 2018 at 12:20pm
	Try to keep your voltage drops to about 0.5 or 0.6V max which is about 5%, same as you would for a 120V branch feeder. That can be hard to do at 12V. I know some folks with a big 12V solar system a long way from their cabin that spent as much on their copper as they did on the solar. SO cord is perfect for the application, fine stranding, good stuff. Got any extra laying around? Ah, sounds like you want to lift the whole pod. rPods use torsion axles, but there is a riser kit available. Lots of folks here have lifted theirs. One little nuance on the 12V batteries. You're going to parallel those of course. When you do, take the pos from one batt and the neg from the other. That keeps the conductor resistance the same so the two batts always take the same charge and discharge currents and stay in better balance.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

Brent S Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 25 Sep 2018 Location: SE USA Online Status: Offline Posts: 21	Posted: 26 Sep 2018 at 11:33am
	Really good to know about just hooking up the solar panels anywhere in line with the batteries. I was a little worried about frying something in the camper.

Brent S Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 25 Sep 2018 Location: SE USA Online Status: Offline Posts: 21	Posted: 26 Sep 2018 at 11:30am
	Luckily we have plenty of spare wire in our shop here. My son and I have a small electrical company together. I hadn’t even done the math for voltage drop yet but wouldn’t consider less than 10ga anyways. SO cord is really flexible and long lasting, very similar to a good heavy extension cord. The jacks just seem kind of low, and one of mine in the rear is different allready, so I imagine the original owner hit something with it. There are shackle extensions that you can bolt onto where the leaf springs mount to give a couple inches more height. I will probably add them down the road. Loosing a jack is one thing, but I’d really hate to loose some plumbing under there. The jacks are all the way out to the corners though, at least the plumbing is closer to the axle and is more protected. Probably not much to worry about but caught my attention when I noticed one had been replaced allready.

Brent S Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 25 Sep 2018 Location: SE USA Online Status: Offline Posts: 21	Posted: 26 Sep 2018 at 11:21am
	Normally I would have gone for 2 6v deep cells, but I got 2 12v AGM marine batteries on a good sale from sears. They are 92 amp hrs each, but are slightly larger than the ‘golf cart ones’. Together they are about 3/4” too wide to fit between the tongue like the original battery rack is. I will cut it off (it’s pretty corroded anyways) and just weld a new one onto the top of the tongue arms. I have a large miller welder but also a small Lincoln wire feed that is great for small jobs like this. My plan was to get this to play with, but first I need to do a few things to get it going. Same thing with the gas tank rack, I will just cut off the old one and weld the one double one I just got from amazon onto it. With moving the batteries forwards an inch or two it’s fairly tight but will all still fit.

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 26 Sep 2018 at 10:58am
	Oh, and I forgot to mention it, but dual GC2 size golf cart batteries in the appropriate plastic cases should already fit in your battery rack. That give more than 200 amp hours battery capacity.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

GlueGuy Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 15 May 2017 Location: N. California Online Status: Offline Posts: 2660	Posted: 26 Sep 2018 at 10:55am
	You can use smaller gauge wire if you locate the solar controller next to the batteries. Then the solar panel(s) can be higher voltage, which will result in lower current, which means smaller gauge wire. Almost all the panels we have been using have an open circuit voltage in the 35-40 volt range, which needs to be stepped down to work with a 12VDC system (if you're only using one). The arrays we use on our remote solar sites are usually connected serially, so we see open circuit voltages in the 300-500 volt range, and run them through an MPPT controller which will step down the operating voltage to whatever you need.
	bp 2017 R-Pod 179 Hood River 2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost