AGM or Wet Cell

[DumnMad]

AGM are great if you are leaving your boat off power for 6 months. Maintenance free - whereas Wet-Cell require regular water top-ups and regular charge top-ups.

Its horses for courses.

[sailorboy1]

[QUOTE=a64pilot;2446063]Sailorboy I respect your knowledge, I really do.
However I'll say it again, it's not how big the solar array is, is the number of hours of charge you get in an average day./QUOTE]

No and yes. No that the size of the bank doesn't matter. Yes the number of hours matter. But with solar it's the number of hours at absorption. A larger bank does bulk changing faster. That gets to absorption sooner . That allows more hours at absorption to fully charge. If your 1000w of solar can't do that for your battery bank on a sunny south Florida day, you sir have a problem!!!! You should find out want it is and try to fix it. Maybe your installation is such that your panels are getting shaded and therefore are a waste of money. But your blanket statement that 1000w isn't enough to charge 660ah house bank for an average cruiser is wrong! That sir is the statement you made and are defending by suggesting that I dont know what I'm talking about.

[a64pilot]

OK I'll say it differently then
A 10,000 watt Solar array won't get your battery bank to fully charged most of the time year round, unless maybe you live on the equator.

Size of the charger isn't the issue time to charge is, it takes up to seven hours to fully charge a depleted Lifeline bank, shallower depth of discharge, less, but not much less cause the initial charge goes fast, its that last 10 % or so that takes so long.

I wish Maine Sail or other expert would chime in and settle this.
In truth I hope I'm wrong and that you really can more often than not fully charge your battery bank from Solar alone year round, excepting days of overcast conditions, rain and other bad weather.

[sailorboy1]

I quit!!!

[a64pilot]

Originally Posted by sailorboy1

I quit!!!

Me too

I'll buy you a beer though in Brunswick though

[john61ct]

Originally Posted by a64pilot

In truth I hope I'm wrong and that you really can more often than not fully charge your battery bank from Solar alone year round, excepting days of overcast conditions, rain and other bad weather.

Yes you are, yes you can.

Start out at 100%.

Put more in than you take out.

Done.

---------
Some setups the "more" needs to be 115%, others it's 108%, etc, good monitors will tell you.

If you only draw down to 50%, have a good CAR chemistry bank, then the morning genny run will help you get there, you just get to know how many AH your bank gets from solar in X hours, given the days' conditions, if that is say 23% then start running your high-amp charger off the genny early enough so the bank is at 80-85% before the solar starts cranking high amps.

But **thousands** of boaters and RVers do it every day with solar alone.

Even if you have a 200AH bank and 200W of solar it can be done, by keeping consumption low.

400W of solar for that 200AH bank would make it easier.

Summer or winter, Equator or Alaska, put more in than you take out, and you will get the bank back to 100% every damn day.

[sailorboy1]

Originally Posted by a64pilot

Me too

I'll buy you a beer though in Brunswick though

because beer here is free at the marina?

[a64pilot]

Originally Posted by sailorboy1

because beer here is free at the marina?

OK then I'll take you into town and buy you and your wife a Pizza or maybe Barbecue if there is any around worth having. My Wife likes Pizza though, only time we have ever had food poisoning it was from bad Barbecue bought at a gas station on I-16, many, many years ago, but that kind of did it for her and Barbecue.
Daughter will be going to College there so we will have access to the Prius.

[Kenomac]

Sailorboy and 64pilot,

If I can jump into the middle of your lovefest. I think a few things going on explain the difference of your opinions, things I've noticed on my own system.

I'm presently at anchor just like I was three weeks ago, but now the daily solar is unable to keep up with usage in late July unlike three weeks ago. The difference being.... the daily temps have been in the 90's, water temp in the mid 80's and the heat causing added resistance in the wiring also has to be a factor with no cooling wind. The refrigeration is running all day, and solar is just staying ahead of it by 5-10amps with our 450w system.

Plugged into shore power, I wouldn't notice such a difference. Solar production is relatively steady but usage is way up, so much less going into the bank.

[john61ct]

Originally Posted by Kenomac

The refrigeration is running all day, and solar is just staying ahead of it by 5-10amps with our 450w system.

So you're risking food poisoning when it gets **really** hot?

Have you got active fan+venting clearing hot air away from the condensor & electronics? That can make a real difference.

Maybe not practical ATM but consider adding a **lot** of insulation to your ice box next opportunity.

For solar-only, that amount of PV is about right for a decent sized portable unit e.g. https://www.amazon.com/dp/B008VX01P2

Burns maybe 80AH per day, depending. . .

You just need to run your gennie more than you'd prefer.

Sure you can't add more panels?

[Kenomac]

I don't have any idea what you're talking about? Everything refrigeration wise is functioning perfectly fine, it just takes more energy to keep the ice box at -17 C and the large fridge running when it's hot and the water is warm because we use keel coolers along with ventilation fans.

Nobody is risking "food poisoning."

[john61ct]

OK, but even more so about the relative sizing issue.

It just seemed not that hot for compressors to be running continuously. That low freezer temp is certainly a factor, talk about food-safe 8-)

[beirutsailor]

Flooded are expensive if you do serious cruising without engine and drain the batteries, notably in night time sailing. After 20 times they are dead. AGM an GEL 400 - 1000 times. But need good regulator.

[a64pilot]

I'll try one last time to see if I can get through, I'm really hard headed.

It is not that my array can't provide more power than I'm using, it can easily. I'm not using more than 300ish AH in a 24 hour period.

If I leave myself on Solar my batteries will never go dead, they will cycle daily likely between 70ish percent to 90ish. However everything will work fine and it will look as everything is fine, cause it is, the bank is not walking down in charge so that after a week or so it's dead, the array is replenishing all the power that is used.

However due to the time required to trickle charge that last few percent of charge in, they are never really getting to a 100% charged state.

The morning hour or so generator run is not to ram more amps into the battery bank, it is to extend charging time by one hour so that the bank gets the time that it takes to dribble in the last few percent of charge every so often. You could just as easily run the generator in the late afternoon into early night, just it won't be loaded much so maybe you would want to heat water or run an AC or something.

[a64pilot]

Li-Po batteries would fix this issue, with them maybe I would never have to burn any fuel at all to charge batteries cause they don't like to be 100% fully charged, they like being cycled between about 50% to 85%, and their charge acceptance rate is through the roof anyway.