Solar, off grid and heat problem

[newhaul]

Originally Posted by Dockhead

Winter sailing is a special joy, understood perhaps not by all sailors.


One other comment -- don't use propane heaters on a boat! They are forbidden by ABYC -- for good reason! -- and may void your insurance.

In the UK more sailors are killed by propane explosions or being suffocated by using improperly vented heaters, than any other cause.

Dock I really doubt that propane heaters are all in violation of abyc have you never seen the force 10 cozy cabin marine heater, or the Dickinson newportmpropane heaters. http://dickinsonmarine.com/product/n...yABEgJcTvD_BwE

[newhaul]

Originally Posted by mr-canada

12V/24V 30A Solar Charger
https://solarsystemdepot.com/collect...roller-charger

Digital voltmeter, programmable and adjustable. Up to 30A, will disconnect power and reconnect it automatically based on battery charge to prevent damaging deep discharge.

Panel is being bought second hand. 150W 8A. Yes comes with a built in diode, mono-crystalline, rigid glass with aluminum frame, separated cells. From my reading, panels of this type do not fight to feed current to shaded cells as each cell is independent and run directly to the diode. I might be wrong on how they wire it, but that's how I read the literature on mono-crystalline panels.

---

Upon re-read I think perhaps it was mentioned that the unit could handle powering a diesel heater, but I am not sure if it was an actual heating unit running directly off the solar or if it was an autostart diesel.

I looked at that controller you linked tom
and it is a POS not worth 5 bucks, but if you are dead set on it just PM me your address I will send you one for free you just pay the shipping.
Here is a much better and adjustable pwm controller.https://www.windynation.com/Charge-C...628?p=YzE9MTc=
And if you search a bit on eBay you will find it cheaper.

[john61ct]

That controller is too cheap, can get for $6 incl free sipping from China. Not adjustable to take the battery up to charge specs, won't last long.

Spend $100 get a Victron 75/15, very robust and adjustable, dependable piece of kit. And likely get 20-30% more power to the batt. Most importantly get batt to 100% not go to float too early.

[john61ct]

Windy Nation bit better but no Victron.

Difference is price of one meal out

[GILow]

Originally Posted by mr-canada

Panel is 3.5x5 ft. All isolated cells, single mono-crystalline, rigid, glass and aluminum frame.

As for efficiency, I'm reading from:
Which Solar Panel Type is Best? Mono-, Polycrystalline or Thin Film?

Unless my basic electronics knowledge is completely out of whack, I can't imagine a 30A controller not being able to take a 150W panel that can push a maximum of 8A in perfect conditions; in theory it should be complete overkill, which is fine by me, better to be overpowered and less heat on the controller because it's capable of far more power than to short out on the controller and have it screw up because its overloaded.

Panel puts out up to 30V at 8A of 150W, but that is perfect conditions. It is designed as a 12V charging system, it is coming off of an RV on a 12 volt system.

Your basic electrical equation is OK but your reasoning is incomplete.

Yes, the controller can (theoretically) handle the power BUT, power is volts x amps.

If your panel voltage exceeds the controller specifications then you will either (best case) lose a lot of potential output or (much more likely), fry the controller and get no output.

Anyway, others here are sensibly suggesting you steer clear of that controller and I agree. I thought it looked good at first but the absence of any meaningful specifications suggest to me that it is likely to be rubbish.

[mr-canada]

Newhaul / What is the model/spec of the one you'd give me for free if I pay the shipping? Where are you located?

I have asked them for the full PDF owners manual so I can get better specs. Still waiting. They are shipping from Montreal but it is undoubtably from China. So is everything else these days though, hence Trump.

[mitiempo]

Originally Posted by john61ct

Windy Nation bit better but no Victron.

Difference is price of one meal out

Victron 75/15 is a bit more in Canada - $169 Cdn.

Excellent choice though.

[Paul Elliott]

Originally Posted by mr-canada

Panel puts out up to 30V at 8A of 150W, but that is perfect conditions. It is designed as a 12V charging system, it is coming off of an RV on a 12 volt system.

Is 30V a typo? Perhaps it should be 20V?

30V x 8A = 240W
20V x 8A = 160W

If that is actually 20V open-circuit, and 8A is the short-circuit current (this is often the way panels are spec'd, although there should be more data), then this would likely be a 150W panel, suitable for a 12V system.

I believe that your controller should handle the panel just fine. There may indeed be better and/or cheaper controllers out there, but it's going to do the job.

However, if the panel truly puts out 30V @ 8A, then something isn't adding up.

[Dockhead]

Originally Posted by newhaul

Dock I really doubt that propane heaters are all in violation of abyc have you never seen the force 10 cozy cabin marine heater, or the Dickinson newportmpropane heaters. http://dickinsonmarine.com/product/n...yABEgJcTvD_BwE

As I said -- marine suitable propane heaters do exist. The burners have to be sealed to the room they are heating in order to pass ABYC.

[john61ct]

20V is fine for PWM, but I've seen 12V nominal go higher.

MPPT needs much higher, usually 40+V, and better to get that with one panel rather than series'ing

[newhaul]

Originally Posted by mr-canada

Newhaul / What is the model/spec of the one you'd give me for free if I pay the shipping? Where are you located?

I have asked them for the full PDF owners manual so I can get better specs. Still waiting. They are shipping from Montreal but it is undoubtably from China. So is everything else these days though, hence Trump.

OK the controller I will give you ( and I have on hand ) is a cmtd 10 12/24 volt and 10 amp pwm controller
Here is the PDF spec sheet and owners manual for the cmtd series controllers
http://felis-net.com/manuals/F0550-B.pdf

Now I am in Seattle Washington area. Zip 98443

[newhaul]

Originally Posted by Dockhead

As I said -- marine suitable propane heaters do exist. The burners have to be sealed to the room they are heating in order to pass ABYC.

Dock not to make an issue but you did say that propane heaters are forbidden by abyc .
Not that most are not allowed.

[Dockhead]

Originally Posted by newhaul

Dock not to make an issue but you did say that propane heaters are forbidden by abyc .
Not that most are not allowed.

Yes, you are right.

I did go on to say:

"There ARE propane heaters which are suitable for marine use (sealed burners and so forth), but they are rare and expensive. See here: https://www.practical-sailor.com/blo...s-11860-1.html"

but you are correct that the statement in my first post on this was not exactly correct. Thanks for the correction. "Most are not allowed" would be the right way to say it.

[newhaul]

Originally Posted by Dockhead

Yes, you are right.

I did go on to say:

"There ARE propane heaters which are suitable for marine use (sealed burners and so forth), but they are rare and expensive. See here: https://www.practical-sailor.com/blo...s-11860-1.html"

but you are correct that the statement in my first post on this was not exactly correct. Thanks for the correction. "Most are not allowed" would be the right way to say it.

Here is the one that scares me and they claim it is acceptable for marine use Propex HeatSource HS2000 6,500 BTU Forced Air Propane Heater 12 Volt

[Pete7]

Can we go back to basics please because this is a 26ft yacht unless I am mistaken.

Firstly the 150w solar panel is going to produce what? about 2 amps at noon during December and January and that's when its not raining, snowing or just a drab grey day. I am at the same latitude and last winter our 80w panel kept the batteries charged but that was about it. Using solar to heat something? no chance.

Mr C, you said earlier that previously the damp was so bad it was "like raining inside". Well the first thing you need to do is sort out the ventilation, then add more ventilation and when you have done that, add ventilation. The boat can go down to -15 without any problems if you have winterized it, but it must be dry and well ventilated. We are on a pontoon without water or electric in similar temperatures. We don't heat the boat but we do have 6 vents in the deck to allow the air to circulate. If you seal up the boat you will have damp and mildew very quickly in weeks, particularly in areas were air doesn't easily circulate. We made the mistake of sealing up a previous boat, never again.

We do lift the saloon floor boards so the heat from the sea water reaches the inside of the boat which means we don't need to drain the fresh water systems.

When you want to visit and stay on board then run the diesel heating long and hard for the visit but do keep the hatch open during this so you ventilate the boat properly.


Pete