Help with small setup

[jim58]

I plan to start with a small 200 watt setup to learn the basics. I'm thinking 2 100w flexible panels to use as portable.


A 40 watt controller so I can add 300w on the roof in the future.


For a small 500 watt setup do/should I go with an mppt controller?


I would like to buy the contoller once, wire it up for the full 500 watts but only use the 200w portable to begin with.


I'm new to solar so any ideas on parts wire sizes, circuit breakers, etc would be huge help.


Jim58

[twinboat]

I would buy the newer technology of the MPPT controller. I have bought 3.

Just as I would buy a pure sine wave inverter or 3 to 4 stage smart charger.

The MPPT controller gives you the flexibility of using higher voltage panels and smaller gauge wiring.

[Charles M]

Originally Posted by jim58

I plan to start with a small 200 watt setup to learn the basics. I'm thinking 2 100w flexible panels to use as portable.


A 40 watt controller so I can add 300w on the roof in the future.


For a small 500 watt setup do/should I go with an mppt controller?


I would like to buy the contoller once, wire it up for the full 500 watts but only use the 200w portable to begin with.


I'm new to solar so any ideas on parts wire sizes, circuit breakers, etc would be huge help.


Jim58

Youtube is your friend.

After spending over a thousand learning with a starter solar setup, I would now do it all differently, and saved enough for a Battle Born 100AH battery.
I would either not try to use solar at all, or just get a Victron MPPT controller with bluetooth and probably just one or maybe two Renogy residential 300w panels.
Good luck.

[vito.a]

I would not recommend flexible solar panels. Too many early failures.
I would recommend at least one 200w panel. The BiFacial 200W + 25% panels seem to work well on an RV. You will find you have limited roof space and need to use the most efficient panels.
https://www.ebay.com/itm/200-25-Watt...AAAOSwbWZacTa~

I think you should start with an MPPT controller unless your coach already has a PWM controller. Why buy it again?
Enjoy. It can be fun setting up your own system.

[SteveJ.]

Originally Posted by jim58

I plan to start with a small 200 watt setup to learn the basics. I'm thinking 2 100w flexible panels to use as portable.


A 40 watt controller so I can add 300w on the roof in the future.


For a small 500 watt setup do/should I go with an mppt controller?


I would like to buy the contoller once, wire it up for the full 500 watts but only use the 200w portable to begin with.


I'm new to solar so any ideas on parts wire sizes, circuit breakers, etc would be huge help.


Jim58

The flex stuff is getting better but would still go with a folding suitcase setup for your portable if you can make it work. You should be able to find them without a controller. Get the MPPT controller.

With portable and later, roof top, you likely will have two separate feeds to the controller. Do try to keep the controller as close to the battery as you can and use wiring from the controller to the battery sized to meet the projected current. Wiring panels in series will help the MPPT controller be more efficient and let you use lighter wiring.

Do get some sort of monitor so you can track amp hours in and out of the batteries. It can be done without but you are almost blind without it. Even the cheapos from Amazon work OK for this.

Do some reading up at Handy Bob solar.

[John Hilley]

I would use two 100 watt panels and install hinges to make a foldable. Then when you are ready, you can mount them on the roof. I also would start with a MPPT controller.

You would need a DC breaker for the PV side and the battery side of the controller. The breaker acts as both an over current device and a switch. The surface mount DC used in auto sound systems work well.

[PbdBlue]

Originally Posted by vito.a

I would not recommend flexible solar panels. Too many early failures.
I would recommend at least one 200w panel. The BiFacial 200W + 25% panels seem to work well on an RV. You will find you have limited roof space and need to use the most efficient panels.
https://www.ebay.com/itm/200-25-Watt...AAAOSwbWZacTa~

I think you should start with an MPPT controller unless your coach already has a PWM controller. Why buy it again?
Enjoy. It can be fun setting up your own system.

Interesting. I know that flex panels permanently mounted on the roof have been an issue but in a portable situation would expect them to be more robust. I'm considering going with flex panels for portable myself. Have two 100 watt rigid panels hinged currently and frankly I am growing tired of dealing with the weight\bulk of them. Anybody have experience with flex panels used as portable?

[jim58]

Originally Posted by PbdBlue

Interesting. I know that flex panels permanently mounted on the roof have been an issue but in a portable situation would expect them to be more robust. I'm considering going with flex panels for portable myself. Have two 100 watt rigid panels hinged currently and frankly I am growing tired of dealing with the weight\bulk of them. Anybody have experience with flex panels used as portable?

I like how you think. I was thinking flexible because of the weight. Figured I could rig up PVC piping as stands...tie strap them together as a DIY suitcase build. Easy peasy from what I'm thinking. I plan to keep them as portable setup, even after I mount to the roof. Everything I'm reading leads me to believe the flexibles fail sooner due to heat from being stuck on roofs without air flow.

If anyone has had any better luck running them in open air as portables I'm all ears.

Jim58

[jim58]

Originally Posted by SteveJ.

The flex stuff is getting better but would still go with a folding suitcase setup for your portable if you can make it work. You should be able to find them without a controller. Get the MPPT controller.

With portable and later, roof top, you likely will have two separate feeds to the controller. Do try to keep the controller as close to the battery as you can and use wiring from the controller to the battery sized to meet the projected current. Wiring panels in series will help the MPPT controller be more efficient and let you use lighter wiring.

Do get some sort of monitor so you can track amp hours in and out of the batteries. It can be done without but you are almost blind without it. Even the cheapos from Amazon work OK for this.

Do some reading up at Handy Bob solar.

The batteries are under the steps. I have a storage bay to the left that I plan to put all the gear in. I should be able to add 2 more 6 volt batteries and the controller within 2 feet of each other.

What do you suggest for an economical MPPT? 40 Amp.

[SteveJ.]

Originally Posted by jim58

The batteries are under the steps. I have a storage bay to the left that I plan to put all the gear in. I should be able to add 2 more 6 volt batteries and the controller within 2 feet of each other.

What do you suggest for an economical MPPT? 40 Amp.

Renogy stuff has worked for me and the prices seem reasonable.

A bit of advice, do get the battery temperature probe.

[PbdBlue]

Originally Posted by jim58

I like how you think. I was thinking flexible because of the weight. Figured I could rig up PVC piping as stands...tie strap them together as a DIY suitcase build. Easy peasy from what I'm thinking. I plan to keep them as portable setup, even after I mount to the roof. Everything I'm reading leads me to believe the flexibles fail sooner due to heat from being stuck on roofs without air flow.

If anyone has had any better luck running them in open air as portables I'm all ears.

Jim58

My thoughts exactly. My opinion is that flex panels don't do well when glued down and exposed to the elements 365\24 hrs a day. Portable use should be much less
harsh. For two 100 watt panels a 15 amp MPPT controller is more than adequate. Also another consideration is parallel vs series. I currently have my two 100 watt panels wired in series with a Victron 15/75 MPPT controller mounted near the batteries in the coach. This allows long cable runs with very low loss. For example 50' at 10 amps in parallel config with 10 ga cable results in a loss of 5.6%. The same in series results in a loss of just 1.4%. The situation is worse yet if you use a PWM controller mounted at the panels. I have a 25' cable on the panels and a 25' extension cable. Both are 10 Ga low voltage lighting wire from Home Depot with Anderson Powerpole connectors.

Don't be alarmed at the price. They also sell it by the foot in the store.

https://www.homedepot.com/p/Southwir...3501/204210683

https://powerwerx.com/anderson-power...mp-unassembled

For what it's worth I have 650 watts on the roof but this is my portable setup when I'm camped in the trees. It has proven to work well.