recommendations for solar panel system monitoring. (1 Viewer)

[tayzoid1]

I am a complete noob with this stuff, lets get that out of the way. I have read and somewhat understand the terms and ideas associated with solar, but deal with me if i get confused or mixed up with this. i have renogy 100 watt kit. no battery yet (recommendations on amp hour rating?) my goal is to be able to run a fridge (have not purchased yet) and a fan at night into my tepui rtt. Ill have some led lights on my trailer and some linear actuators to raise the rack, all of this being momentary and not used much. I have read threads were people are able to measure the actual usage or live usage of their system while running. i can't find the correct terms for this gauge or monitor. the closest thing i have found that i think may work is a radio controlled battery charger monitor, 150 Amp Watt Meter WITH SPECIAL HEAVY GA Wire Wind Generator Solar DC Inline.
Would something like this work for my system, or would anyone be able to point me in the right direction? i am just wanting to be able to monitor my usage to insure that I'm not left stranded.

Thanks!
Taylor

 

[GeoRoss]

I have had good luck with one month of testing one of these.

https://www.amazon.com/bayite-6-5-100V-Display-Multimeter-Voltmeter/dp/B013PKYILS

They come in 100A and 20A versions. I purchased the 100A and have found it to be overkill. The 20A version has an internal shunt, so less wiring and bulk. I have two, one monitors the incoming solar and the second will monitor the output from the battery when I build version 2.0 of the distribution box.

I have a GT PowerAnalyzer. The voltmeter on it is about 1V off but the unit is effective for just keeping an eye on the amps and watts.

 

[tayzoid1]

Will the unit in the Amazon linked unit also show amp hour readings? Would this be necessary?

 

[GeoRoss]

No, for that you start to get expensive. Others can better advise you on that route. I don't really think it is needed, you can make a pretty good estimate on the battery state of charge from a voltmeter. I just check the battery in the morning before the panels start charging it so the battery is at rest as much as it ever is.

Using a 100W panel, a simple PMW charge controller with a 100Ah battery that only powers an 80qt fridge, I never saw the voltage drop below 12.6V overnight over the course of a month of essentially base camping. That is >90% battery capacity to start the day. At first I would realign the panels to the sun throughout the day. I quit doing that and just kept them pointing south. There was no change. This was even true on days that were mostly cloudy.

 

[tayzoid1]

Wow that sounds great! I was going to run 2-3 100amp hour batteries figuring I would get a week or so of usage before needing to shut down and charge. This is great news! I was debating on making a connector between my truck battery and trailer solar/battery system to charge with the alternator while I travel, but I'm not sure if that would be worth it now.

 

[opg4759a]

You need to measure your batteries in watt hours not just amp hours which is the correct way to start planning your power needs.

To figure out watt hours (Wh) you take the voltage of the power source and multiply it by the Amp Hours (Ah) so for example a 12 volt DC battery (12.6V) that is 100 Ah would be 1260 Wh which is the equivalent to running a single 60 watt light bulb for 21 hours or a 1 watt led for 1260 hours. 5 watt phone for 252 hours. Now granted this doesn't take into account voltage drop so I would recommend figuring a 12 vDC system at 12.4 volts to account for usage overnight when not charging.

Energy is watt-hours = amp-hours x volts
Power is watts = amps x volts

Remember if your battery is reading 12.0 volts you are at 25% capacity left. So the more you can keep batteries charging the happier they will be in the long run also when out and you are stopped for a long period it would be worth setting up the solar panels just to continue to charge don't wait a couple days.

 

[tayzoid1]

I actually plan to permanently mount the panel on top of my trailer so it will charge anytime it is available. Think I should make an umbilical cord to connect the trailer power system to the truck alternator/battery system? Does that make sense? Basically hardwire jumper cables back to the rear bumper and make it quick disconnect so it can charge with the alternator while the truck is running.

 

[opg4759a]

It's not hard to to wire up a trailer plug that will allow you to charge a battery going to a 6 or 7 pin trailer plug would be the easiest way to do this and you aren't having yet another cable off the back of your truck to the trailer.

 

[NLXTACY]

Something like this? Yeah it's for a fridge but can easily be for solar panel.

 

[tayzoid1]

It's not hard to to wire up a trailer plug that will allow you to charge a battery going to a 6 or 7 pin trailer plug would be the easiest way to do this and you aren't having yet another cable off the back of your truck to the trailer.

I never even thought about the power and ground wires on the 7 pin plug. That would be perfect!

Something like this? Yeah it's for a fridge but can easily be for solar panel.

View attachment 1314168

That isn't a bad idea at all either! I'm now curious if the power and ground in the 7 pin plug is enough wire to charge the system.

 

[NLXTACY]

It all depends on the wattage. I've setup a few MorningStar charge controllers and just used Metri-Pak connectors.

 

[tayzoid1]

I really like that distribution panel. I don't plan to run an inverter, but this is a great idea that I can run multiple sockets with. I've also thought about trying to run a isolated post's through the side of my trailer so I can connect wires directly to the battery (jumper cables or temporary connections. Great ideas guys!

 

[Fast Eddy]

I've also thought about trying to run a isolated post's through the side of my trailer so I can connect wires directly to the battery (jumper cables or temporary connections.

An Associated polarized socket would be just the thing, though they are expensive.

 

[tayzoid1]

that would be perfect! you guys rock!

 

[JCruse]

I wanted an amp hour meter too but everything I found was so expensive, $100 to $500, but some really nice stuff.

I eventually found this:

It was cheap - $20

It has amp hours instead of watt hours (didn't know the formula back then)

And unlike everything else I saw, it fit in a single switch space on the dash!

It's only rated to 10A but I really only wanted to watch what the fridge was pulling, so at less than 3A it's good to go. I may even add in the head unit one day as I only use the pre-amp section.

One day I'd like to spend up and get something like those 100A units so I can track everything, plus Ah going IN to the battery.

Somebody find me one of those for cheap!












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[JCruse]

Oh BTW... If you're looking to buy a low current draw fan then do yourself a favor and get the right one the first time. I'm talking about the Caframo 757. I tried two $20-$30 low amperage fans and they were both weak as hell. The Caframo blasts quite a good breeze. It's more like having a small 120V AC home fan, but without the wastefulness. I used to go up into the hot tent and hold the others right up to my head/face to get any kind of cooling at all. And it was minimal. This one I can leave clamped to the poll on high using about 2A and feel a wonderful cooling breeze that cools me down in no time so I can fall asleep, and leave it on all night with no concern about the batteries. My first two fans sucked by comparison and from the reviews I see they're all about the same.

I payed $44 for mine (plus about $50 bucks total for the other two, trying to save money ) but I see the 757 on EBay now for $35. Not bad...

Caframo 757DCWBX 12 Volt 2 Speed 7 inch Direct White Wire Cabin Fan | eBay








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[tayzoid1]

I ended up buying one of these 10

I got the one that only takes 110 and batteries. I ended up using a 9 volt power supply cable ran to the 12 volt battery and it works great. I want something a little bigger but so far 14hours it ran great. And that's with no solar. I'm still working on my solar mounting solutions.

 

[jonshonda]

I have a family of four (3 and 5yo) and want to use heater, radio, waterpump, lights w/o too much worrying in fall/spring (using a 12ft pup). I went with a Morningstar Duo setup (w/ temp sensor) for the controller/monitor. We have one Renogy 100w Mono panel, and I found some nice 10 gauge wire at work for a 35ft extension cord to the panel for when we need to chase the sun. We currently have one US Battery 155ah golf cart battery, but may require two depending on how cold it is.

Plans for led lights, another battery, and solar liners for the bunk ends are in the works, but not in the budget. I did a lot of research for the solar system, and found that while the Bogart Engineering setup was superior in info access, it was much more expensive.

 

[tayzoid1]

Sounds like a good setup! I too plan to run a water pump to a propane water heater on my expo trailer

 

[jonshonda]

Sounds like a good setup! I too plan to run a water pump to a propane water heater on my expo trailer

Our biggest current draw will be the furnace fan, but that is because we only use the pump for dishes and washing hands, or rinsing off outside. We are going camping this weekend, and it will only get down into the mid-40's, so no big concerns for staying warm.

Its kinda funny that I bought all this solar stuff cuz I couldn't add more batteries to the camper based on weight concerns with our TV (sienna), but now that I have the extra weight capacity with the GX470, I kinda want to dump the unused solar setup in favor of 2 or 3 more batteries. The last thing I want to be doing is chasing the sun around all day when camping...but I guess it would be kinda fun and a good (albeit expensive) conversation piece having a 2x4' panel at our site.