people with portable solar panels...

[john61ct]

Renogy is a company good at mass marketing, focus on low price and making things (appear) easy for the prospective buyer.

Their target customer thinks you can just go online and order quality panels, and does not want to bother learning about the details.

They also deliver a much higher level of customer service than most of the companies competing in that (non-) niche of the market.

So great at what they do, good recipe for profitability.

However, they do **not** sell top-quality gear for those desiring optimum performance.

Getting that requires more work, more research, but not necessarily (much) more money.

SCs that are bundled with panels are shite IMO.

 

[calicamper]

Most of these little charge controllers are designed for power boxes where the whole kit is in a box so the controllers typically have a temperature aspect that lets them cut power or other steps to limit issues if temps are out of range etc.

I would mount the controller right next to the battery for all the reasons mentioned. Its more or less how they were designed to be used.

 

[Martinjmpr]

Mine are mounted to the back of the panel like yours.

I understand that this is not ideal but sometimes "simple and convenient" is more important than extracting every watt of power that you can get.

Make a system too complex or difficult to use and people simply will not use it. Eventually I'll move the controller closer to the battery but what I have is "good enough" and sometimes "good enough" is, well, good enough.

 

[Swiftone]

Well, I am here to both learn and ask questions. Served me well so far and I am hard to embarrass.

 

[rayra]

I moved my PWM controller off my panel and into my rear power module in my Suburban. I'm backfeeding my under-hood Aux battery thru ~16' of 1/0 cable. Without any noticeable trouble.
I didn't want the controller on the panel, on my roof cooking all the time.

 

[dwh]

A dedicated (separate from fixed panels) controller is inside next to the battery, you'll have less losses if the high voltage side is the longer run, and the controller can do temp compensation if its capable..

PWM. There is no high-voltage side.

Too far away and the controller has no real idea what the battery voltage is and may persistently over/under charge your bank..

It knows battery voltage. With PWM the solar operates at battery voltage.

 

[luthj]

.....

It knows battery voltage. With PWM the solar operates at battery voltage.

PWM operates at the battery voltage minus the wiring drops. The PWM controll will regulate its output to maintain the desired voltage at its output terminals. Because lead acids charge voltage has a major impact on rates (and the quality of the charge), modest voltage drops in the controller to bank wiring can have significant effect.

I generally argue that its best to located the controller closer to the battery, all else held equal. I also suggest less than 1% voltage drop at the typical charge rates.

 

[dwh]

PWM operates at the battery voltage minus the wiring drops.

Following that logic would mean the solar is operating at battery voltage minus wiring drops.

 

[luthj]

Yeah, sorry I phrased that wrong, its plus wiring drops. The point I was trying to communicate is the battery may be seeing 14.1V with the controller regulating to 14.2 or 14.3V at its output terminals. A tenth of a volt can make a significant different in absorb time.

 

[john61ct]

And battery longevity.

Yes the key is for the controller to do a good job it needs to sense the voltage and temperature accurately.

Hence better to be close to the battery.

Thick wiring can help, but it is a compromise

 

[Swiftone]

So I have taken these suggestions to heart and modified my system. Rewired my panel to 12 feet of #10 Zip wire with Anderson Power Pole connectors, Velcro'ed the controller to the back of the panel (for storage only) and when in use will have the controller sit on my center console and plugged into the APP port in my dash. This puts about 4 feet of #12 Gauge between the controller and the battery. I did not want to put it under the hood and redo the current wiring running thru a Blue Seas fuse block (which also takes up the available room on the firewall). Doing that would only shorten the controller/battery wire run less than 2 feet

This also gives me the option of charging my LiFeP04 solar 40 ah battery pack in the field just by setting the controller to lithium settings and plugging it in. The 10 Ga run is long enough to put the panel in my bed if the sun angle is favorable.

If I get super motivated I have a temp sensor that plugs into my controller that I can run thru the firewall and tuck the plug end till the panel is deployed.

Not a perfect solution but we are talking maybe 10 to 12 days a year beach camping.

 

[hour]

Damn dude today I learned what zip wire was. I've been looking for something like that for an eternity and the best I found was low voltage landscape lighting wire which is super soft to the point that separating the two wires can expose one of them as it tears too much. And I just spent $50 on a roll of 12 gauge copper that's in a thick jacket and impossible to manipulate. So, thanks for that new rigging looks legit though

 

[luthj]

I really like this stuff myself.

10-2 AWG Gauge Marine Wire Tinned Copper Boat Cable Flat Duplex

10 AWG Gauge 2 conductor marine wiring is flat duplex DC boat wire Made in the USA and flexible with fine stranded tinned copper

www.genuinedealz.com

 

[dreadlocks]

I use the stuff @luthj linked now, ZIP is fine for indoor projects.. but I've got a 30ft strand of 12awg ZIP that was left outside, I cut it in half and stripped it, had corroded from one end to the other and was full of cancer..

probably fine for a portable panel used a few times a year, but no good if you wanna use that portable panel to provide a maintenance charge while in storage, or any fixed panel.. I expect my tinned marine cable w/pvc jacket to last decades w/out worry.

 

[Swiftone]

I use the stuff @luthj linked now, ZIP is fine for indoor projects.. but I've got a 30ft strand of 12awg ZIP that was left outside, I cut it in half and stripped it, had corroded from one end to the other and was full of cancer..

probably fine for a portable panel used a few times a year, but no good if you wanna use that portable panel to provide a maintenance charge while in storage, or any fixed panel.. I expect my tinned marine cable w/pvc jacket to last decades w/out worry.

Hey - I am a HAM and a old street racer so "I run what I brung"

Seriously my portable panels are stored inside and brought out in sunny summer California weather for a few days at a time.