Solar Panels for Marine Use

[Biggusstickus]

Originally Posted by JK n Smitty

Your fridge and freezer hours seem a little off to me. You have one running 12 hours at night and the other 8 hours. My experience is they don't run that often. You are not opening them and therefore they are holding the cold better. Also the temperatures are cooler at night generally. When I did my power consumption estimate I had the refrigerator running 8 hours per day. Now that I am actually measuring with my battery monitor I am seeing even less than that.

I would recommend you install a battery monitor and do some real world tests versus your calcs before you purchase the solar panels.

Fair winds,

Jesse

Jesse your quite correct and whilst I put 50% cut out in the column I did not carry it over into the figures as I though it might be better to stay a bit higher just in case. By your figures I could possible save 40ah per day (fridge only) at anchor which would be great although on our hot summer nights the fridge does get opened often . These figures were based on a 2-3 day trip (5hrs a day engine time) however I am planning a 14 day trip into the wilderness where there will be no fuel supplies so I plan on only 2hrs engine running time a day and 2 hrs generator running time to make the 1600litres of fuel I will carry last.

Therefore I really want to go a little overboard so I don't end up with any issues. Currently I only have 2 x SN150 batteries and a smaller battery for the genset so the solar would be beneficial to me. As would 2-3 x 150 ah AGM batteries.

I shall implement your idea thanks and install a monitor to get some more accurate figures.

Any suggestions most welcome thanks as a) I am not the most electrically minded person around and b) I have not undertaken a trip as long as this on my boat before.

[cwyckham]

Great to hear you're installing a monitor. This is an absolute must in my mind. The first two things I would do on an average new to me boat would be to upgrade the anchor and install a battery monitor.

[hellosailor]

I think the BP panels also have no warranty exclusion for marine or vehicle use.

MOST panels will have a warranty that is void if they are used on any moving vehicle (car, boat, truck, unicycle) as well as void for marine use. If the maker doesn't have an express written warranty available on their web site, or the maker is located outside of your home country (and is not a major international company) you basically have no warranty worth relying on.

I've seen references that the panel failure rate is much higher than anyone is talking about. But then again, when some panels are 1/2 the cost of others, it may be worth gambling. Also note that Congress is putting something like a 30% tariff on Chinese panels, so those bargain prices may zoom soon.

[Snowpetrel]

Scary how it all adds up... Good to see you actually posting some figures instead of vague generalisations that dont really help anyone. The bilge blower seems a big draw, does it really run all the time while underway? Chart plotter seems lowish unless its a small unit. Go to add in depth sounder, and all the little parasitic instruments that are attached. Cheers, and I am keen to see others energy budgets posted ane hear how yours stacks up in the real world.

[Rustic Charm]

Originally Posted by Biggusstickus

Yes quite right StuM and I shall change it. It was put together in a bit of a hurry yesterday and I mainly did it so tedsherrin would have a bit of an idea on what his consumption may be. Mistakes do happen

Thanks. I am paying attention but been hit with 'man flu' which now has developed into pneumonia. I too am going to purchase a battery monitor. I had not finished my figures but they look similar to yours, probably less.

[Rustic Charm]

What is a recommended battery monitor from posters? I like the look of the Nasa Clipper instruments but they are nearly $300?

[Biggusstickus]

Originally Posted by Snowpetrel

Scary how it all adds up... Good to see you actually posting some figures instead of vague generalisations that dont really help anyone. The bilge blower seems a big draw, does it really run all the time while underway? Chart plotter seems lowish unless its a small unit. Go to add in depth sounder, and all the little parasitic instruments that are attached. Cheers, and I am keen to see others energy budgets posted ane hear how yours stacks up in the real world.

Thanks for the reply
I am having some issues with the Bilge fume alarm at present (it stays on beeping) so whilst I have checked and checked for leaks and fumes and found nothing I am thinking it must be a faulty sensor so just taking precautions and leave the blower on whilst underway until I can replace the unit.
Its a Raymarine RL70c plus Chartplotter which they say uses 10w but I have allowed 4amp for other instruments and now included some Radar figures which I forgot to add although I rarely use radar due to very few vessels being around where I live and we choose our weather carefully.
I am not too concerned about my underway figures as the 2 x 70amp alternators handle it well its the long shutdown periods that will catch me out if I don't do something.

[Rustic Charm]

I'm looking at getting a Nasa BM-2 or a BM-1. (Good old British tech). The BM-2 accepts load and charge up to 200amps and the BM-1 accepts up to 100 Amps.

Using Biggusticks amp sheet (as I've not finished and I think it will be similar ) do I need a BM-2 which does the charge and load up to 200 Amps? I have a 90amp alternator and will have two 120 watt solar panels.

[StuM]

Originally Posted by tedsherrin

I'm looking at getting a Nasa BM-2 or a BM-1. (Good old British tech). The BM-2 accepts load and charge up to 200amps and the BM-1 accepts up to 100 Amps.

Using Biggusticks amp sheet (as I've not finished and I think it will be similar ) do I need a BM-2 which does the charge and load up to 200 Amps? I have a 90amp alternator and will have two 120 watt solar panels.

The most you will get at any time with a 90 amp generator and 240 watts of solar under ideal situations is about 110 amps. So peak loads would be stressing the BM-1. However, the actual draw depends on the capacity and state of charge of the batteries. Can your battery bank absorb 100 amps?

[Rustic Charm]

Originally Posted by StuM

The most you will get at any time with a 90 amp generator and 240 watts of solar under ideal situations is about 110 amps. So peak loads would be stressing the BM-1. However, the actual draw depends on the capacity and state of charge of the batteries. Can your battery bank absorb 100 amps?

I don't know Stu, I'm getting four 120am AGM's. So that's 480amps. Is that what you mean?

[Biggusstickus]

Originally Posted by tedsherrin

I don't know Stu, I'm getting four 120am AGM's. So that's 480amps. Is that what you mean?

Hey Ted, Just noticed your up in Launceston, I live in Hobart. Where are you sourcing your Monitor from, I had a look at the Elite ones and they are up around $330 as well.

Been pricing AGM batteries and they are up there too!!

Dave

[Rustic Charm]

Originally Posted by Biggusstickus

Hey Ted, Just noticed your up in Launceston, I live in Hobart. Where are you sourcing your Monitor from, I had a look at the Elite ones and they are up around $330 as well.

Been pricing AGM batteries and they are up there too!!

Dave

Hi Dave, well, I've been doing some investigation though the day and the best I've come up with is the Nasa Clipper instrument. $285 on ebay from Queensland with free postage. Can't get it cheaper overseas either. It seems the good quality ones such as this, Energise, Victron, Xantrex are all up in the $300 mark. Jaycar have one for $130 but I went and had a look at it in launceston and didn't like the look if it.

My question that Stu answeredwas because there is a BM-1 which overseas is $100 cheaper but is only a 100 amp. So I think e BM-2 is a good one. The Queensland site has 100% feed back too.

12volt Battery Monitor Nasa BM 2 | eBay

[StuM]

Originally Posted by tedsherrin

I don't know Stu, I'm getting four 120am AGM's. So that's 480amps. Is that what you mean?

Yep, under bulk charging by the alternator plus full sun, you could be putting more than 100 amps into a 480 amp hour bank, so go for the larger monitor.

(And 100 amps is only 1.2KW, so if you run a 2KW inverter, that would also peak at well over 100Amp draw.)

[Rustic Charm]

Originally Posted by StuM

Yep, under bulk charging by the alternator plus full sun, you could be putting more than 100 amps into a 480 amp hour bank, so go for the larger monitor.

(And 100 amps is only 1.2KW, so if you run a 2KW inverter, that would also peak at well over 100Amp draw.)

Thanks Stu, I just purchased the BM-2. Thanks for your assistance.

I'm really getting this B.O.A.T thing now. 'Bring on another thousand'.

[capt-couillon]

Very small small boat, with limited space for panels while offshore. Managed to find the new Renogy RNG-100DB which I am waiting for as we speak.
Semi-flexible (30deg arc) True mono-crystalline cells (not thin film) Fully encapsulated (No glass glazing) 42.9"x21.3"x1/8". For me, a perfect fit on top of the lazerette between the backstay and mainsheet track. 3 pounds net weight. From the Renogy lit "The laminate coating on the exterior of the panel makes it impervious to saltwater splashing, rain, and other weather elements. While this panel may be damaged by sharp objects or scraping, there is no risk of shattering or cracking. "
$200 direct from Renogy .

Pairing it with a 30A pwm controller (again from Renogy $30) to allow for 2 additional panels while on the hook.