Marine Applications for the Midnight Kid

[dmkkeng]

I'm installing (4) 100W Flexible Solar Panels and the Midnight Kid Controller on a 42’ Catalina Sailboat. The flexible solar panels will be mounted on the top of my canvas enclosure. The (2) 100W flexible panels mounted on the port side of the canvas enclosure will be connected in series as will the (2) 100W flexible panels mounted on the starboard side of the canvas enclosure. The port side and starboard side solar panel arrays will be connected in parallel. The following questions are in reference to the 12V Battery Solar Panels in Parallel drawing on the Midnight Solar website.

Question #1 â€" Is the installation of the ground fault breaker applicable to the installation on a fiberglass boat? The flexible solar panels will be mounted to the canvas enclosure using Velcro and sewing, the breaker panels and controller will be mounted to fiberglass surfaces and the batteries are mounted in a fiberglass enclosure.

Question #2 - Same question for the requirement of the SPD300, is it required for a fiberglass boat/ marine application?

Question #3 - Does the Midnight Kid with the Whiz Bang JR option perform the same function as a battery monitor? Can it provide information on the State of Charge of the batteries? Is there any benefit to purchasing a battery monitor in addition to the Midnight Kid/ Whiz Bang JR?

Question #4 - Any comments on my solar panel configuration? The reason I have configured the panels this way is due to a slight slope from the center of the enclosure to the edges (the port side panel array will be at a slightly different angle with respect to the sun versus the starboard solar panel array) and, the potential for one side of the boat to be affected by shading more than the other. This assumes that a series solar panel configuration is affected by shading more than a parallel solar panel configuration. I’m open to suggestions as it is difficult to sort fact from opinion when researching on-line forums regarding solar panel configurations on a boat.

Thanks

[Resthome]

#1 - I don't use a GFB on my installation on my boat. Just panel mount Midnite DC Breakers. The Panel mount breaker are not polarity sensitive like the DIN rail breakers are

#2 - If you are in a area that gets a lot of lightening then probably a good investment.

#3 - The WBjr purpose is to measure what is going in and out of the batteries not what is going out of the controller. It's also there so you can terminate Absorb with End Amps because loads are not an issue when figuring out End Amps setting. It can let the controller preform battery monitoring functions such as SOC. (Not familiar with the Kid as I use a Classic)

#4 - What size battery bank are you trying to charge? What is the Vmp of the panels.

[dmkkeng]

Thanks for the info - I usually follow manufacturers recommendations however what is shown appears to be somewhat excessive. I'm located in the Pacific Northwest, there is not much lightening.

Do you install a breaker for each panel or just a single breaker for all panels? In my configuration it would be easier to combine all panels with a single feed to the controller. What is suggested in the wiring diagrams is to run to separate feeds from the port and starboard array through 15 amp breakers and then combine them both into a 30 amp breaker.

The house battery bank (12V) is 660 amp hours (6 - 6V batteries), Vmp of the panels is 18V, I believe max current is around 7 amps.

[Resthome]

Each string of 2 in series should have a breaker. And then a breaker for the combined PV at the controller so all PV can be shut off. Also at the controller a breaker from the battery bank.

I think you will have trouble charging a 660Ah battery bank with only 400 watts of panels. Remember you are going to only see about 70-75% of the manufacturer rating out of the PV in typical operation. My first system only had 640 watts trying to charge a 840Ah battery bank and they where definitely undercharged. Depending on the boats running loads it will cut your charging ability even more.

[dmkkeng]

Breaker configuration makes sense - I was thinking two 15 amp breakers feeding into a single 30 amp breaker from the panels to the controller and a 30 amp breaker between the batteries and controller. Any insight into where the breakers should be located? Can you use a fuse instead of a breaker?

I figure my daily power usage to be somewhere between 150 and 175 AH, as back-up I'm going to purchase a Honda or Yamaha 2000W generator. I'm also installing an external regulator and bypassing the internal regulator to improve motor charging. To reduce power consumption I upgraded all lighting to LED. To be completely self sufficient, using solar, I figured I needed at least 500W of solar panels - I can fit 4 solar panels on top of my enclosure behind the boom, finding a spot for the 5th would be a challenge. Also I would need a 2nd or larger controller.

[Resthome]

Breakers can be used as disconnects and Midnite DC breakers can be switched under loads. You can not do this with fuses so I would advise against fuses. The two 30A breakers should be close to the controller. The two 15A breakers should be near each of the strings. Use MN panel mount DC breakers they are made for DC solar use. Do not try to use Home Depot type breakers. MN also make some nice small boxes for mounting these breakers.

Boats are always a challenge And to stay within Coast Guard rules and probably your insurance policy always use Marine Grade wire on a boat.

[dmkkeng]

Are the Midnite DC breakers ignition proof? I'm not sure if the requirement for ignition proof breakers is just for gas engines or if it includes diesel engines. I don't plan to locate the breakers in the engine room or near the batteries however I do have a diesel heater in close proximity to where the breaker panel would be located.

[zoneblue]

None of those carling breakers are ignition rated. In fact quite the opposite, no ignition proof breaker has a very high interupt rating. Its how they work. So keep them at least 500mm from any ignition hazard. In a marine situation maybe more!

[Resthome]

USCG Boat Builder's Handbook - Electrical Section on Ignition Proof atached.  In other words keep it away and separated from Gasoline and Propane. 

The requirements for circuit protection is extensive and to large to post here. The issue I had was it had to be a very short distance (inches) from the power source (ie Batteries). My batteries are in the engine compartment so I had to use Blue Sea ANL Ignition Protected fuses at the source. The Midnite DC breakers and controller are located inside a clothes closet on the wall. Breakers are in a Midnite Baby Box. PV breakers are in a Midnite Combiner box mounted under the canopy where the panels are mounted.

I visited the lake today to check on things between storms. Everything is fine and batteries are reading SG 1.280. The main marina wasn't as lucky. They sustained major damage and broke two of the small boat slip dock arms off the main marine that hold up to 150 boats each. Apparently they had sustained winds of 50mps with gusts to 60mph rapidly switching directions yesterday for about an hour.

Always fun trying to figure out where to put this stuff and comply with USCG rules. Good Luck and happy sailing!

[dmkkeng]

Thanks for the information - it appears gasoline and propane are the main concerns. I think I'm going to use the Midnite Baby Box in the rear storage area for the two 15 amp panel breakers and the same beside the controller for the two 30 amp breakers. The combiner box is physically to large otherwise I would use it in the rear storage area - I like the idea of having the breakers covered to protect them from inadvertently being switched off. The main AC breaker for my boat is also located in the rear storage area and has no cover to protect the breaker switch from being turned off. I have already had incidents of the breaker being turned off while loading or unloading items into the storage area.

I would definitely use ignition protected breakers anytime I connect directly to the batteries. Another option for my configuration would be to would be to eliminate the 2nd breaker box at the controller and install two 15 amp and a single 30 amp breaker in the Midnight Baby Box in the rear storage area and install a Blue sea ignition protected breaker at the battery.

There is nothing simple about any boat project ...

Good to hear there was no damage to your boat -  I lost my foresail and radar due to high winds in November.

[Resthome]

I worried about tripping the breakers also since they were in a box that stuck out from the wall and in a closet with clothes near by. But after 5 years I haven't had a problem with them. I even researched a mechanical lock for them. I even believe Midnite makes one not sure as I don't know exactly where I found it. I'll look around.

[Resthome]

Here is the plate to prevent tripping.

http://www.midnitesolar.com/productPhoto.php?product_ID=286&productCatName=Breakers&productCat_ID=16&sortOrder=23&act=p

[zoneblue]

Where space is limited , if you are using flexible panels, make sure they arent amorphous as they are oo large. THe flexible sunpowers on the other hand are some of the highest efficiency there is and for your application are a good fit.