Series or Parallel Panels?

[noelex 77]

Originally Posted by dfelsent

I’ve got three panels tied to three controllers. The wiring for each panel is separate.
As the shading moves around each panel / controller produces what it can.
Given the cost of a panel why not spring for the extra controller?
What you gain in efficiency you can save in panel size.

All true, but perhaps not ideal in this case.

Normally using a single controller per panel provides the highest overall power output on a yacht, but these panels still have the issue of a Vmp lower than 16.8v. So these panels are not ideal for this configuration, especially with the popular Victron controllers in hot conditions.

[thomm225]

Originally Posted by tamicatana

Well… ABYC ain’t in it, is there?

Your connection is not breakered/fused, it isn’t solid, and it sounds like your wiring may be undersized, although in your defense you did not elaborate how large your panels are.

If your alligator clips should happen to bounce off underway, you now have a dangerous short and likely fire.

Gat insurance?

Really?

The current coming of my panels would be quite low and there would have to be a return line of some sort to get current flow as I see it.

So one clip coming off one end of two batteries would have a hard time creating current flow.

When I settle on a particular setup, I'll probably attach the wires directly to the terminals without the clips.

I usually just have the clips on the panels that I hook directly to the batteries without the use of a controller and that is usually when I'm anchored

At this time, I'm searching for some longer leads to my inverter. These big batteries make that necessary.

[noelex 77]

Originally Posted by tamicatana

Should be a CRIMPED connection. Your rig is unsafe.

There have been numerous threads debating which is the superior method of electrical connection on a boat, soldering or crimping.

In practice both methods are fine if well done.

Alligator clips, on the other hand, are a bad idea. There are much better methods of arranging a power connection that needs to be periodically disconnected.

[thomm225]

I'm using the alligator clips at this time while experimenting with my setup.

Plus the alligator clips allow me to disconnect from the controllers/panels whenever I have a full charge and am not sailing.

When I decide how everything will be connected permanently, I'll use some terminal connectors like I have before, but many times with those, I have to reseat the connection periodically to get full current/voltage to the batteries.

[flightlead404]

I'm considering going in parallel with three separate PWM controllers. That solves the shading issue and the charge start point issue, and keeps the controller cost lower.

I just need to check if there's space for the wiring. Back on the boat tomorrow.

[noelex 77]

Originally Posted by flightlead404

I'm considering going in parallel with three separate PWM controllers. That solves the shading issue and the charge start point issue, and keeps the controller cost lower.

I just need to check if there's space for the wiring. Back on the boat tomorrow.

The need for multiple regulators only really applies to MPPT controllers. The advantage is that the input voltage of each panel can be optimally controlled.

This does not apply to non MPPT (PWM) regulators. The input voltage will always be the battery voltage. So there is very little or no power production advantage installing and wiring multiple PWM regulators. Often the increased self consumption will produce a net loss. Just wire the pannels in parallel with a single controller.

[Nicholson58]

Originally Posted by thomm225

You have assumed a lot in a short time.

Wiring size is fine.

And my system is fused to the load.

20 watt panel 14 gauge wire. (soldered on by me)

65 watt panel 14 gauge wire (for the last 9 years soldered on by me)

50 watt Renogy with it's own wiring maybe 12 gauge.

20 watt panel hooked up direct to batteries.

I have sometimes all connected and sometimes none while at other times 1, 2, or 3 panels connected.

Panels are tied on so I can turn them toward the Sun or just laying on a lazarette locker.

The 20 watt panel has fallen off here.

Get a proper solar charge controller with MPPT and a program specific to your battery type and leave it connected. The controls will go to float for lead-acid or off for lithium.

[Stu Jackson]

Originally Posted by Nicholson58

Get a proper solar charge controller with MPPT and a program specific to your battery type and leave it connected. The controls will go to float for lead-acid or off for lithium.

We've had this discussion with him elsewhere, N58. But don't worry, "Alligator Clip Man" knows it all, or at least he'll tell you that. Dontcha know those clips make it easy to disconnect his solar panels? Doesn't everybody disconnect them? Doesn't everybody use one panel without a controller, too?

[thomm225]

Originally Posted by Nicholson58

Get a proper solar charge controller with MPPT and a program specific to your battery type and leave it connected. The controls will go to float for lead-acid or off for lithium.

I have 2 proper PWM Controllers that will go to float also. Yesterday, I adjusted them to 14.7 volts for a while then back to 13.4 volts before I left.

My MPPT Victron Controller failed after one year. It may not have like how I switch and swap my panels around or that sometimes I hook panels directly to the batteries without a controller. (or I simply shorted it out somehow during a panel change)

I may though buy one of the new Victron Controllers with Blue Tooth now that I have an iPhone.

And btw, I used the generic term alligator clip above for my battery terminal clips.

[thomm225]

Originally Posted by Stu Jackson

We've had this discussion with him elsewhere, N58. But don't worry, "Alligator Clip Man" knows it all, or at least he'll tell you that. Dontcha know those clips make it easy to disconnect his solar panels? Doesn't everybody disconnect them? Doesn't everybody use one panel without a controller, too?

Most folks don't know they can use panels without a controller so what everyone else is doing isn't a concern of mine.

Usually I have my 20 watt panels stowed when sailing and just use the two you see in my videos. (The 65 watt and the 50 watt panel) Then at anchor if I need extra charging, I'll "clip" on direct to the batteries one or both my 20 watt panels and aim them directly at the Sun.

As far as my "Battery Terminal Clips" they are great to use when testing.

I used alligator clips to fix my old jeep wiring so it would pass inspection.

Btw, picture is of my old unit. (just found that photo this week online) In the long shed with metal roof toward the water (which is the ICW Atlantic East Coast in NC) is where we kept the generators that supplied our power. They provided 3 phase 400 HZ steady power after they settled down.

I was a Radar/IFF Tech

The two Raydomes close to the runway on the right of the raised walkway housed our PAR Radars. The ASR and IFF system is in a van back with the Tech Vans and Control center behind the tower. Everything was deployable even the runway.

Radars were all tube and transistor technology

Other photo is of an A6 jet arrested landing. We had a short runway there.

Same place today, well video is 2012 but with newer equipment. We did have Harriers though in the 1970's but they crashed a lot back then. They were loud though and stayed nearby due to hovering capability

Notice wind indicator on the nose of the Harrier. Great for hovering help.

https://www.youtube.com/watch?v=tnlgHqmXXgM

[Nicholson58]

Originally Posted by Stu Jackson

We've had this discussion with him elsewhere, N58. But don't worry, "Alligator Clip Man" knows it all, or at least he'll tell you that. Dontcha know those clips make it easy to disconnect his solar panels? Doesn't everybody disconnect them? Doesn't everybody use one panel without a controller, too?

I disconnect mine for lightening or service. Each panel is connected by a two pole breaker. The MPPT out goes through a larger two pole breaker. Charge controller at float. Wiring should be pretty permanent and connections tight and reliable. I have had almost all electrical problems traced back to crimp and other shaky connections. All were repaired with silver solder and shrink wrap filled with 3M or silicone before shrinking. These never fail.

Pics.
Three panel breakers and MPPT main
MPPT Morningstar at float.

Panels are 220 watts each, 54 VOC. After the breakers the wires are gathered on large junctions. Total panel parallel output goes to the MPPT. A large rotary switch permits charging house 1 or house 2. Other two pole switches determine which house thermocouple is sensing. Bogart battery monitor for each house bank.

[thomm225]

My $15 PWM Controllers give you voltage but no Float indication so you need to know the Float Voltage setting or you can check it right quick.

The Charge arrows may stop blinking.

I can't remember since soon as I see the voltage I know.

[donradcliffe]

One word of caution on parallel panels. In researching the cause of a flexible panel fire, I discovered that most panels are made to withstand an internal short if two panels are connected in parallel, but if you add more, you will have to provide protection against shorting.

[Stu Jackson]

Originally Posted by thomm225

Most folks don't know they can use panels without a controller so what everyone else is doing isn't a concern of mine.
......................

I guess Maine Sail would beg to differ. But, ach, what does he know....

[thomm225]

Originally Posted by Stu Jackson

I guess Maine Sail would beg to differ. But, ach, what does he know....

Thanks.

Exactly my point.

I don't know what he knows or any of the other member, but I do know what will work and have been doing that now for a few years.

My first setup was a 15 watt panel no controller. (2011)

And for those that don't know, you have to monitor your voltage when you do a direct hookup to the batteries with a panel or you could overcharge them. Best to unhook at 14.4 volts or so.

But when with my old 12 volt 90 ah batteries there was rarely a chance of that when I was running autopilot, inverter, computer, 19" monitor/HDTV, VHF, Depth, and sometimes both computers and lights. Plus Fan over night.