Help! Winter Solar Panel Charger/Tender System

[CourageousME]

Im doing a great deal of reading and was gifted a beautiful new 300Watt semi-flex solar panel.

As I read on here and other forums, Id love some expert input on what I need besides the panel to effectively tend/charge (i.e. keep my batteries topped off) over the winter. Inside storage is not an option.

So, any good plug-n-play systems out there for me? Im on a fast timeline....just got the panel and the boat is about to be wrapped next week.

Thanks in advance!

[Bleemus]

Any quality MPPT charge controller and some wire and connectors and you will be good to go.

[hellosailor]

If you have that one panel and only one battery, maybe 100Ah rating, then you'll be able to use any charge controller, evewn a cheap PWM one. Avoid the dirt cheap no-name Chinese stuff, you never know if there are just rocks in the box. Your one 300W panel probably puts out around 17 amps. If perfectly oriented it would average five hours of that power output during a whole summer day, i.e. 55 Amp hours per day, round number. In winter and lying flat and not oriented? Maybe 25-30Ah per day, which would really overcharge your battery, unless you had a huge battery bank or, again, used a charge controller. You should have enough power so that using a more expensive MPPT controller is a waste of money, for winter storage charging. But it may be worth the expense, if you use the panel as a primary charging source during sailing season.

[CourageousME]

Originally Posted by hellosailor

If you have that one panel and only one battery, maybe 100Ah rating, then you'll be able to use any charge controller, evewn a cheap PWM one. Avoid the dirt cheap no-name Chinese stuff, you never know if there are just rocks in the box. Your one 300W panel probably puts out around 17 amps. If perfectly oriented it would average five hours of that power output during a whole summer day, i.e. 55 Amp hours per day, round number. In winter and lying flat and not oriented? Maybe 25-30Ah per day, which would really overcharge your battery, unless you had a huge battery bank or, again, used a charge controller. You should have enough power so that using a more expensive MPPT controller is a waste of money, for winter storage charging. But it may be worth the expense, if you use the panel as a primary charging source during sailing season.

This is really helpful. I think for the winter I will have the panel headed south....6 batteries all together on board. 4 house, a starter and a windlass battery. They are alll hooked together in some fashion LOL....but not exactly sure how.

Id like to integrate this in to a charge system for sailing in the future, but the pressing time to jerry rig this before shes is put to bed is the priority.

can you point me to some decent charge controllers? and also, do I attach the controller to the same end of the battery bank that the existing charge system for shore power is attached?

Im seeing some terms above I am not familiar with...MPPT?

many thanks again captains!

[Bleemus]

Good advice. If your not really using the boat a lot you can get a PWM controller like a Morningstar Sunsaver SS-6-12V for $38. Bulletproof little units that should work fine for you.

[Bleemus]

To get you through the winter get the Morningstar Sunsaver SS-6-12V. Cheap and will be fine for the winter.

Without getting all technical an MPPT controller converts extra voltage into amps providing faster charging. A PWM does not do that but still works fine for your use.

[CourageousME]

Originally Posted by Bleemus

Good advice. If your not really using the boat a lot you can get a PWM controller like a Morningstar Sunsaver SS-6-12V for $38. Bulletproof little units that should work fine for you.

awesome! just picked it up on Amazon Prime for 46$ free shipping, plus a red and black cable with the MC4 connectors.....

I guess I need to lastly know where on the battery bank I connect the Positive and Neg lead from the charge controller.... not familiar with this stuff but as usual, you guys are the bestest!

[hellosailor]

With six batteries, there may be some issues. There will be voltage drops from wiring losses between the batteries, and they will depend on how well the wiring was done, how thick the cabling is, how clean all the contacts are. You might want to connect the solar power to the "middle" of the system, as best you can approximate that. Or, run the leads to the farthest apart positions that you can, i.e. the positive of the forwardmost battery, and the negative of the rearmost, in an atempt to let the wiring losses "average out" rather than impacting each battery separately. In theory your battery charger (alternator? shore charger?) is already connected at one "right" point and you can connect the solar charger to the same place. But if those batteries were added in higgly-piggly over the years, you may find there's a better way to connect a charger now. Certainly worth looking over all the connections, and cleaning or replacing as needed before the winter storage.

[Bleemus]

Connect them to the same battery terminals that your engine alternator leads go to and make sure you clean them up real good with a wire brush.

[CourageousME]

doing some planning- looks like a 20' run of wire from the panel to the Sunsaver- and I will mount that in the battery box- so only 12-16" of wire from the unit to the battery terminals.

10G wire ok for that?

[smac999]

Most likely this will only charge one bank. And the other 2 will not be charged.

So connect to the house bank with a fuse.

you need to know how they are hooked up and how they charge off shore / engine. And you already said you didn't know.

[CourageousME]

Originally Posted by smac999

Most likely this will only charge one bank. And the other 2 will not be charged.

So connect to the house bank with a fuse.

you need to know how they are hooked up and how they charge off shore / engine. And you already said you didn't know.

But I have a minimal skill level that can be useful. Safe to assume that the big fat RED wire coming from the engine connected to the batteries is coming off the alternator, right? Thats the battery terminal I should aim to connect my positive off the controller, right?

[steamgoat]

You are in Maine,check out your local experts site !
Welcome To MarineHowTo.com Photo Gallery by Compass Marine How To at pbase.com
Plenty of info there. My boat is already winterized in VT. Golf cart batteries are fully charged and disconnected,if last winter is any guide,they will still be at 12.6 volts in March. Have a nice winter, Bruce.

[nitpik]

All I do for the winter is raise the solar panel to a fairly steep angle to shed snow. If you leave it horizontal, it won't do you much good with two feet of snow piled on it!

[smac999]

Originally Posted by CourageousME

But I have a minimal skill level that can be useful. Safe to assume that the big fat RED wire coming from the engine connected to the batteries is coming off the alternator, right? Thats the battery terminal I should aim to connect my positive off the controller, right?

Then hire someone.

The big fat wife is your starter wire and should go to a switch, then to battery. If you connect to this battery most likely only your single starter battery will get charged. And the other 5 will not.