Solar questions?

Jan 12, 2016
268
Hunter 410 Ladysmith, BC
I'm considering a solar project for our H410 and am looking for advice...

I will likely get an arch fabricated that can hold solar panels and davits in the stern of the boat with the hope of mounting 200-300 watts of solar wired in series. All will run through an MPPT controller mounted close to the battery bank. My reasoning for series is to keep the wire gauge lower for the long run back to the bank/mppt.

I am also considering replacing the factory small deck solar panel with what is offered here at SBO.
https://shop.hunterowners.com/hp/part.php?m=410&c=15&p=55119

I have a single house bank of 750 a/hr with six individual 6V Trojan 125's and one 12V starting battery.

Now the questions:

1) Would I be better off running the small panel on the roof deck to only the starter battery rather than the battery switch? Conversely the big bank solar would only deal with the house bank. Or...would I be better off running all through both banks combined.

My concern is that combined the starter battery will be getting sent bulk charge when it's not necessary, or the house bank will get float charging when it needs bulk because of the difference in size between the two. (750 ah deep cycle versus 125 ah and minimal cycling.)

2) Can I later on add flexible panels to my bimini/dodger and combine them further in series to the other panels provided the MPPT controller can manage the voltage? Or does each set of panels need its own MPPT controller? If so how does one ensure that bulk/absorb/float gets achieved properly?

The loads on the boat are the factory refrigeration/freezer, plus electronics, lights, and sparking up the espar hydronic to either heat the entire boat, or just the hotwater tank depending on the season. Interior lights are all LED, biggest draw is the fridge and exterior lights, followed by electronics when sailing (autohelm, chartplotter, stereo), the espar probably only uses 5-10 amps a day max in summer sailing.
 

Nodak7

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Sep 28, 2008
1,249
Hunter 41DS Punta Gorda, FL
Lurker, just completed a solar panel install on our 41DS. It is a Solartech 285W Panel with a Victron MPPT Controller. Our battery bank is the same as yours and our biggest draw is the Freezer and refrigerator as well. The Panel handles them quite nicely. We do lose some battery percentage during the day when we are sailing but overall it has been a very successful install. It is wired to the house battery and not the starter battery. The panel is mounted on our dinghy davits. Picture attached. Yes each panel needs its own Mppt which controls the charging.
 

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Jan 12, 2016
268
Hunter 410 Ladysmith, BC
Hi Nodak,

That set up looks really nice! What davits did you use, and were the mounts for the solar custom?
 
Jun 14, 2010
2,081
Robertson & Caine 2017 Leopard 40 CT
You should run solar to the house bank. Your engine charge to the start bank. Add a “battery combiner “ between the two banks. The battery combiner is a voltage sensing relay that will only interconnect the banks when the voltage in one bank is at 13.2 v or higher.

Since the voltage will not go that high unless the bank is charging in float mode, it will allow the charging source to charge a discharged bank first and then combine both banks only when the charge is high, charge acceptance is lower, and charge level is sufficient to top them both off.

It is in-essence an auto-combine switch. It is also “lossless” because it doesn’t cause any voltage-drop between the banks (diode-based “battery isolators” have a 1.5v drop, and also heat up).

Balmer Digital Duo Charge is a battery isolator, not a combiner or voltage sensing relay. ACRs or Automatic Charging Relays are another name for voltage sensing relay. An example: Blue Sea 7611 ACR

If you’re looking at a unit that has heat sinks (metal fins on the chassis) then it’s an “isolator”, not an ACR.

Ps. I don’t sell these things, but I’ve used them since 2001 when I installed my first solar setup. I haven’t used the Blue Seas unit but the brand I’ve used isn’t made anymore.
 
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Nodak7

.
Sep 28, 2008
1,249
Hunter 41DS Punta Gorda, FL
Hi Nodak,

That set up looks really nice! What davits did you use, and were the mounts for the solar custom?
We have Martek 600 Dinghy Davits. Good for 600#. The Solar Panel and support structure is 65#. Total weight with dinghy, motor and all contents plus panel 333#.
 
Nov 26, 2008
1,966
Endeavour 42 Cruisin
How heavy is that single 285w panel? I would tend favor a pair of 140w panels. Having 2 provides redundancy if one fails plus they would be easier to manhandle should they need removal.
If you add more solar later, I would add a second charge controller, again for some redundancy. I have 2 glass panels on my bimini and 2 glass panels that flip out on the side rails. Each pair has an identical controller. I was able to adjust both controllers to matching settings.
 

Nodak7

.
Sep 28, 2008
1,249
Hunter 41DS Punta Gorda, FL
How heavy is that single 285w panel? I would tend favor a pair of 140w panels. Having 2 provides redundancy if one fails plus they would be easier to manhandle should they need removal.
If you add more solar later, I would add a second charge controller, again for some redundancy. I have 2 glass panels on my bimini and 2 glass panels that flip out on the side rails. Each pair has an identical controller. I was able to adjust both controllers to matching settings.
Getting, the panel weighs 40#. Two 150's (if you can find them) weigh 52# and take a bit bigger foot print and heavier support structure. I wanted minimum weight and maximum output. That was how I came to the decision for the 285w. Looks like the new norm for panels is in the 300w range.
 

Nodak7

.
Sep 28, 2008
1,249
Hunter 41DS Punta Gorda, FL
Hi Nodak,

That set up looks really nice! What davits did you use, and were the mounts for the solar custom?
Yes I built the entire mount out of aluminum to save weight. I found some rail clamp mounts that worked perfectly on 1-1/4" rail and went up from there.
 
Jul 19, 2007
50
-Hunter 1995 - 40.5 Hunter Saint Andrews, NB, Canada
I'm looking at mounting 4 x 100w flexable panels on our bimini as after measuring the units and the bimini area I have room for them all. Want to wire them thru a single MPPT controller to my house bank of 2 - 8D AGM batteries, wondering if that will be sufficient to run the fridge & freezer while on the mooring. All lights interior and exterior have been changed over to good quality LED's. Sailing loads would be auto pilot, plotter and instruments. Buying the SBO replacement deck panel and controller for the start battery. I have a 160 amp alternator and presently charge the start battery and house bank thru a Blue Seas ACR.
 
Nov 26, 2008
1,966
Endeavour 42 Cruisin
The semiflex panels have 5 year workmanship warranties vs glass panels that have 20 to 25 year performance guarantees. There's a reason. My 2 100w semiflex panels quit within 6 months. Some people have reported very long life with flex panels, others have not. But I dont recall hearing any bad news about glass panels...
 
Jun 14, 2010
2,081
Robertson & Caine 2017 Leopard 40 CT
I think a common reason flex panels fail is that people walk on them, or they bend them in too tight a radius. They’re often glued or screwed to the deck and then problems can develop if there’s any support gaps allowing localized flex if stepped on. Also, I think people assume they’re more rugged than they are and they’re subject to shoe heels, or a dropped winch handle or hard bumps from the dinghy while launching/retrieving.
 
Feb 6, 1998
11,667
Canadian Sailcraft 36T Casco Bay, ME
The semiflex panels have 5 year workmanship warranties vs glass panels that have 20 to 25 year performance guarantees. There's a reason. My 2 100w semiflex panels quit within 6 months. Some people have reported very long life with flex panels, others have not. But I dont recall hearing any bad news about glass panels...
I have many customers who've had good results with the Solbian or Solara brand semi-flexibles, the Chinese knock-offs not so much. Course the premium products from Solbian or Solara are not inexpensive either. That said a semi-flexible panel, even Solbian, will not last as long as a quality rigid panel.
 
Nov 26, 2008
1,966
Endeavour 42 Cruisin
I think a common reason flex panels fail is that people walk on them, or they bend them in too tight a radius. They’re often glued or screwed to the deck and then problems can develop if there’s any support gaps allowing localized flex if stepped on. Also, I think people assume they’re more rugged than they are and they’re subject to shoe heels, or a dropped winch handle or hard bumps from the dinghy while launching/retrieving.
Not in my case with my 6 month failures. Both failed flex panels were mounted on a 1/2" PVC board so they had ZERO flexing and ZERO walking on and ZERO radius and NOTHING was dropped on them.
 
Feb 6, 1998
11,667
Canadian Sailcraft 36T Casco Bay, ME
There seems to be a bit of confusion around the different charge management devices available. All of the devices are in what I call a category "Charge Management Devices" or CMD's. I lump them into four categories.

Diode or FET Isolating: These devices split charging and isolate banks for back drain via FET's or Diodes. They induce voltage drop and can not be used with most smart chargers or solar controllers etc. that require a 12V signal to boot up. In today's day and age they are akin to dinosaur saddles or buggy whips and have very few justifiable uses on boats. They are usually easily identifiable with their input stud & two, three or four output studs plus aluminum heat-sinking fins. These cooling fins are there for a reason. The reason is that voltage drop creates waste heat and that waste heat needs to be dissipated.

Paralleling Relays: ACR's (Automatic Combining Relays), Combiners, VSR's (voltage Sensing Relays), ProSplit R's, Cyrix, CVSR's etc. etc.. These devices simply parallel banks when a charging voltage is present, with parallel voltages starting at 13.0V & above. They then isolate/unparallel the banks when battery voltage falls below charge level. They combine/close on voltage rise and isolate/open on voltage fall. They are essentially a fully automatic BOTH switch. The ProISO etc. are a staged paralleling relay that are essentially gimmickery marketing and are an unnecessary expense over a properly installed ACR etc... This class of CMD, with the Blue Sea and Yandina models especially, have proven to be some of the most reliable marine specific devices to come down the pike in many years.

Installation is simple on a cruising boat; feed all charge sources to the house bank, insert the VSR between house and start and you're now charging both banks automatically and seamlessly. The Blue Sea ACR models also offers a "Start Isolation" feature for vessels with solar wind etc.. Blue Sea also offers high current "latching" models that can handle 500A continuously and can also be controlled remotely.

Voltage Following Buck Type DC to DC Chargers: Echo Charger & Duo Charger are two devices that fit into this category. They are one way devices that take their input power from the house bank and feed off 15A to 30A to the house bank. They can not boost voltage to a second bank only drop some voltage. They are also "voltage followers" that simply follow the charge stages of the house bank. They can not float a start battery independently from a house bank as many incorrectly assume they do. The Duo Charger has a voltage output limit setting where the Echo Charger is fixed at a maximum of 14.4V on the output, even if input voltage is 14.8V.

Independent DC to DC Buck or Boost Battery to Battery Chargers: Sterling Power DC to DC Battery to Battery Chargers or B2B's. These devices are full featured, fully independent & fully programmable battery chargers that are powered by 12V or 24V DC on the input side as opposed to 120V or 240V AC. The Sterling DC to DC chargers are capable of 2A - 60A and the larger and latest models are fully programmable including absorption duration parameters. They offer both waterproof models and dry-mount models too. These units are equivalent, and in most cases exceed, the capabilities found in the smartest battery chargers, dedicated votlage sensing, battery temp sensing, fully programable, only they are powered by a DC battery bank not 120V or 240V AC.

The newest models, the BB1230 & BB1260, actually offer better programming and features than Sterling's already excellent ProCharge Ultra AC powered chargers. They also allow the mixing bank voltages and battery types on-board as wide ranging as LiFePO4 and GEL....

If you have a 12V house bank but want a 24V windlass? Simple, Sterling has a 12V to 24V model as well as 12V to 12V, 12V to 24V, 24V to 24V & 24V to 12V models. These B2B's can even be set up to boot based on voltage, just like ACR's or Echo/Duo Chargers as well as booting based on ignition-on or manually.


On the low cost side it is really tough to beat a simple ACR. If you want all the bells and whistles the Sterling B2B chargers, especially the BB1230 (30A) & BB1260 (60A) are simply amazing in their capabilities and very reasonably priced for what they can do and offer. For the price the BB1230 for example, eats the Balmar Duo Charger for lunch in what it can do...
 
Dec 19, 2006
5,809
Hunter 36 Punta Gorda
I added 2-195 watt panels from I think E electronics in Miami Fl and pretty sure back in 2010
was a $1.00 a watt and maybe cheaper now.
Look in my profil in my album photo’s show I installed off my arch and very secure neat out of the way and at anchor not much shading and I run 3 refrigerators when cruising so 2-195 watt panels keep my batteries well charged all day for sure and usually charge 2-cellphones and 2 tablets and many boat electronics.
Nick