Solar Basics – please help a layman

[viben]

I have decided to install solar, but with limited knowledge of the technicalities, I find most posts to be hard to understand. Therefore, please help me out, in layman’s terms:

Major DC consumption goes to frige and auto helm

Except for a 1500W water heater and a 900W coffee maker, I have no major AC appliances in regular use. However, it would be nice to be able to run the 12000 BTU Cruisair reverse cycle AC off-grid occasionally.

1. My current housebank is a Napa 8273. My plan is to double capacity by adding another. Does that make sense, or are there better, cost-effective battery solutions out there? Due to space constraints, same size is preferred (LWH: 20 ¾” x 8 ½’ x 10”).

2. Current charging by shore power and engine. The charger is a 55A Quick. Do I need another charger when adding another battery, or will this charger suffice for both?

3. Someone once told me that I should not connect 2 batteries of different age. Opinions?

4. When selecting panels to charge these 2 batteries, what do I need in terms of charging capacity? Does higher panel wattage mean faster charging?

5. in addition to watts produced, what are the other key factors to look for when choosing the panels?

6. When choosing a charge controller, what are the key technical specs to look for when choosing?

7. Do I need additional monitoring beyond what the controller would provide?

8. Would it make sense to also connect the engine battery, or should the solar

9. Would the above be sufficient to run the water heater, the AC or the coffee machine with an inverter? If so, for system protection, would it be possible to install a devise that would automatically prevent these 3 devices to run simultaneously, ie. that only one can be chosen at the time?

10. With this set-up, what are the specs I need to look for when choosing the inverter? (I already have a 400W SeaVolt for electronics.)

Beyond these questions, can you recommend any complete kits, or do you recommend buying each item separately.

I already have a guy that can make the hardware for installing the panels, as well as a marine electrician that will install and wire the rest.

Is there anything else I need to know or consider???

[john61ct]

Originally Posted by viben

I have decided to install solar, but with limited knowledge of the technicalities, I find most posts to be hard to understand.

It would behoove you to do some reading of basic "12 volt" "boat electrics 101" resources, google unfamiliar terms etc to educate yourself.

Google

quality batteries site:

inserting the forum site's domain name to get information

also "flooded vs AGM"

After familiar with the basics and issues, post specific questions, maybe as a new thread.

Originally Posted by viben

2. Current charging by shore power and engine. The charger is a 55A Quick. Do I need another charger when adding another battery, or will this charger suffice for both?

First choose the batteries, then research for the right charger. A link to the manual for your current one will help when the time comes.

Originally Posted by viben

3. Someone once told me that I should not connect 2 batteries of different age. Opinions?

Much better if the bank is perfectly matched. A bunch of cheap batts can be made to work if the same chemistry and charging voltage requirements. Do not put a new expensive bank together with old/cheap batteries.

Originally Posted by viben

8. Would it make sense to also connect the engine battery, or should the solar

Momentary "jump starting" is convenient but rarely needed. Combining while charging is fine same caveats as above, otherwise use DCDC charger if your engines alts aren't enough. But they should be, long as you keep the Starter and House circuits isolated when not charging.

Originally Posted by viben

9. Would the above be sufficient to run the water heater, the AC or the coffee machine with an inverter? If so, for system protection, would it be possible to install a devise that would automatically prevent these 3 devices to run simultaneously, ie. that only one can be chosen at the time?

IMO water heating should not be done from battery. Do that while you're running an engine for some other reason, or directly from fossil fuel, or from PV after banks are full, or solar direct not PV.

AC is a huge load, IMO run engines or even better do without.

See if you can make coffee without an inverter also. Any heat load really same sort of advice.

Originally Posted by viben

can you recommend any complete kits, or do you recommend buying each item separately.

Separately

Originally Posted by viben

Is there anything else I need to know or consider???

Of course, tons 8-)

Originally Posted by viben

4. When selecting panels to charge these 2 batteries, what do I need in terms of charging capacity? Does higher panel wattage mean faster charging?

5. in addition to watts produced, what are the other key factors to look for when choosing the panels?

6. When choosing a charge controller, what are the key technical specs to look for when choosing?

7. Do I need additional monitoring beyond what the controller would provide?

5-6 IMO start a new thread when you've progressed further, 7 deserves its own.

Also read this: http://www.catb.org/esr/faqs/smart-questions.html

[Pete7]

Viben, there are some excellent threads on here about solar. If anything there is too much, so worth spending a couple of evenings reading first. Seems the one common denominator is that folk regret not going big from the start.

Also worth thinking about is were you are going to put the panels. This is worth a read:

http://www.cruisersforum.com/forums/...ts-179638.html

[viben]

Thank you for your understanding, but is there a way to cut through the information overflow? For clarification: To john61ct, I initially suggested installing one additional NAPA 8273 house battery ie. the same as I already have. The rest of the questions should be viewed in that context. To Pete7, yes, I already know where to install the panels - on top of the davits.

[a64pilot]

Originally Posted by viben

Thank you for your understanding, but is there a way to cut through the information overflow?

Not really, you have to understand to make educated decisions, there is no right answer.
However I'd throw out the opinion to forget running high amp devices off of a Solar installation like heaters and AC, I have 1 KW and in my opinion to run an AC, I'd likely need at least four times as much

[john61ct]

Originally Posted by viben

Thank you for your understanding, but is there a way to cut through the information overflow?

Yes, pay a trusted expert their hourly consulting fee to design the system with/for you.

But you of course need a certain level of knowledge in order to be able to discuss your options.

And it can take a lot of research to identify a truly knowledgeable expert, much less one you can trust to look out for your interest rather than just sell you what makes them the highest profits.

Originally Posted by viben

I initially suggested installing one additional NAPA 8273 house battery.

Yes, but if you do some research on batteries, you will understand that is not a good idea.

Is that even a true deep-cycle battery suitable for your application?

http://www.pbase.com/mainecruising/deep_cycle_battery

From your current state of knowledge, best not to be too locked into any one aspect, if you are going to DIY, start learning with an open mind.

[john61ct]

And keep in mind, the solar part of things is just one part, relatively straightforward.

Choose one component at a time, research, google, ask specific questions, come to a decision, then move on to the next piece of the puzzle.

[john61ct]

Originally Posted by viben

yes, I already know where to install the panels - on top of the davits.

So what are the dimensions of the maximum area you have to work with?

That, combined with your climate and latitude, more than anything else will determine what you can run off solar.

Of course you can leverage the solar by supplementing with a morning run of fossil fuel charging: what is your capacity there?

[Geek_Guy]

Here are a couple of simple answers.

1. AC will not run off batteries. There are several thread on CF.

2. Though it would seem the coffee pot should work. I'd not do it. I ran mine off the inverter once and it got so hot I decided that was bad. I use a French press. Actually have decided it is a better option all round.

Other than that I can only second several other replies. There is much to learn.

[Mystic38]

you need to completely forget AC, water heater etc via an inverter.. you WON'T replace that energy via solar at all.



Do you need charging at anchor or while offshore?.. the two scenarios are different.. at anchor the consumption would be 95% fridge, offshore it would be 25% fridge and about 75% autopilot.

So, since i know i spend 90%+ at anchor, I scaled my system to be totally independent at anchor, but need engine assist while offshore.

Since most fridges are about 50aH +/- get a 130W panel, a 25A MPPT charger and be done with it...

then, add a battery monitoring system like a link lite

want better engine charging?.. move up to 100A alternator, external regulator add a second 8D battery... and expect to run the engine for charging while offshore.


regardless of anything you decide, invest in a clamp on ammeter and begin to understand charging profiles and your consumption.

[Copacabana]

Originally Posted by viben

Thank you for your understanding, but is there a way to cut through the information overflow? For clarification: To john61ct, I initially suggested installing one additional NAPA 8273 house battery ie. the same as I already have. The rest of the questions should be viewed in that context. To Pete7, yes, I already know where to install the panels - on top of the davits.

In a way, yes, you can cut through the information overflow. Simply install the most solar panels you can fit on your boat, buy a quality MPPT controller and then learn to live with the power that the system generates. You will have to learn to make do with the amps you generate. It's that simple. AC will be crossed off your list pretty quickly ....

[barnakiel]

I think given the AC known to be a major consumer you are working to the schedule where the solar is a secondary source only.

Once a genset is in place and takes care of 100% of the needs, your choice of solar will simply limit the time the genset is run.

Smaller loads, in short periods, can be run without starting the genset too - as long as you do not exceed the max amps that can be drawn from your house bank.

The overall rule with solar energy is 'you can't have too much' - mostly due to the fact that the solar thing works only by day and is less than 100% of its rating when overcast or otherwise shaded.

'Mount as much as you can fit'. Then enjoy the silence (on the sunny afternoons, anyway).

b.

[travellerw]

Wow you have asked a whole ton of questions in a single post.. I will try to answer what I can based completely on our year and a half of living aboard with 5 people. I reseached and built our system before we left and have still had some surprises. Answers in RED.

Originally Posted by viben

I have decided to install solar, but with limited knowledge of the technicalities, I find most posts to be hard to understand. Therefore, please help me out, in layman’s terms:

Major DC consumption goes to frige and auto helm

Except for a 1500W water heater and a 900W coffee maker, I have no major AC appliances in regular use. However, it would be nice to be able to run the 12000 BTU Cruisair reverse cycle AC off-grid occasionally.

There is no way you will run AC from your solar. You would need at least 1500W of solar and Litium battereis to run AC(based on real experience of buddy boats). Even then, those boats only AC a single cabin (where they sleep), not the whole boat! We do run our water heater off solar, but we have 1000W of solar and the water heater is small with a 500W element. 1/2 hour a day off the inverter gives us enough hot water for 2 nice showers. We have 660AH of batteries installed

1. My current housebank is a Napa 8273. My plan is to double capacity by adding another. Does that make sense, or are there better, cost-effective battery solutions out there? Due to space constraints, same size is preferred (LWH: 20 ¾” x 8 ½’ x 10”).

If budget is no option, the Lithium is the way to go. Otherwise those are pretty tight constraints.

2. Current charging by shore power and engine. The charger is a 55A Quick. Do I need another charger when adding another battery, or will this charger suffice for both?

That charger is fine.

3. Someone once told me that I should not connect 2 batteries of different age. Opinions?

That is correct information. If you add a new battery in parallel to an old one, you are at high risk of killing both (google it).

4. When selecting panels to charge these 2 batteries, what do I need in terms of charging capacity? Does higher panel wattage mean faster charging?

Maybe.. Possibly.. It will depend on your standing draw. If your standing draw doesn't change and you get bigger panels, then yes it will charge faster.

5. in addition to watts produced, what are the other key factors to look for when choosing the panels?

Efficiency. Smaller panels producing more amps

6. When choosing a charge controller, what are the key technical specs to look for when choosing?

I wouldn't buy anything unless its an MPPT controller. We have been using cheap chinese ones for a year and a half and they have been fine. I believe in multiple controllers with one or two panels feeding each one. I'm not a fan of a big MPPT controller with all the panels connected (unless you have a smaller installation, 300W or lower)

7. Do I need additional monitoring beyond what the controller would provide?

Absolutely.. You should have this regardless. Look at AH counters like a Victron BMV-702.

8. Would it make sense to also connect the engine battery, or should the solar

I prefere isolation of house and start banks. Our start and house banks are completly isolated unless I need to connect them. Then I have a relay I can switch to connect for boosting or in the event we loose and alternator and can't charge the start batts from the motors. We never charge our house from the alternators, just not required with our solar install.

9. Would the above be sufficient to run the water heater, the AC or the coffee machine with an inverter? If so, for system protection, would it be possible to install a devise that would automatically prevent these 3 devices to run simultaneously, ie. that only one can be chosen at the time?

With just the batteries you are suggesting.. No I would not run any of those items on solar and battery. UNLESS you plan on installing a huge solar bank. Then you could run the coffee maker when the sun is shining. Probably not the time you want to make coffee.

10. With this set-up, what are the specs I need to look for when choosing the inverter? (I already have a 400W SeaVolt for electronics.)

No way you can run the hot water heater or AC from your inverter.. So look for a 1000W pure sine wave inverter. Again we have had good luck with chinese cheapies on Amazon.

Beyond these questions, can you recommend any complete kits, or do you recommend buying each item separately.

What you are doing is not something you can "buy off the shelf".. I'm guessing you either need to pay someone to do the thinking for you, or you need to spend many hours reading. If you don't do one of those 2 things, you will not get a system you are happy with (or you will WAY WAY overpay).


I already have a guy that can make the hardware for installing the panels, as well as a marine electrician that will install and wire the rest.

Is there anything else I need to know or consider???

[a64pilot]

Originally Posted by Copacabana

In a way, yes, you can cut through the information overflow. Simply install the most solar panels you can fit on your boat, buy a quality MPPT controller and then learn to live with the power that the system generates. You will have to learn to make do with the amps you generate. It's that simple. AC will be crossed off your list pretty quickly ....

After likely 100 hours of reading and research, I finally came to this conclusion as well.
I think it's a lot like a budget, you have to live within what you have in the bank, however if you could increase what's in the bank, then of course you could raise your standard of living. Maybe you can't do that with money, but likely you could with Solar.
Power is like that, I have yet to hear of anyone complain that they have too much Solar, or money, or fresh water for that matter.