Question about battery power

[Drek4]

Just curious about how many batteries do you use in your power grid on your sailboat and if this is enough for your usage. I have seen many people sailing with solar panels and 1 or 2 batteries for their power grid, are deep cycle marine batteries so much better than car batteries?
I was thinking of purchasing 2x solar panels 130/145 watts with a 400w wind generator to supply the batteries, but I want to avoid as much as possible turning on the engine to supply the batteries.

[michaeld]

We have four group 31 AGMs, about 400Ah altogether. Solar is two 175W panels. A third 175W panel will be installed soon. Engine drives a 120A Balmar alternator. Refrigeration is the most power hungry draw. It's a new installation, so performance metrics and experience is yet to be determined.

[Drek4]

Originally Posted by michaeld

We have four group 31 AGMs, about 400Ah altogether. Solar is two 175W panels. A third 175W panel will be installed soon. Engine drives a 120A Balmar alternator. Refrigeration is the most power hungry draw. It's a new installation, so performance metrics and experience is yet to be determined.

Thank you for your reply, much appreciated, I hope you will be posting your results once everything is installed.
Good luck and take care!

[LoudMusic]

You have a lot of research to do on that. There are four or five different battery chemistries, a dozen different battery sizes, several ways to configure them, and twenty or more manufacturers. And that's just the "drop in" style. You could even build your own.

At this point nearly everyone agrees wind turbines are useless compared to solar panels.

More solar more better. But you'll want to do a power budget to figure out how much you use in a day.

[Drek4]

Originally Posted by LoudMusic

You have a lot of research to do on that. There are four or five different battery chemistries, a dozen different battery sizes, several ways to configure them, and twenty or more manufacturers. And that's just the "drop in" style. You could even build your own.

At this point nearly everyone agrees wind turbines are useless compared to solar panels.

More solar more better. But you'll want to do a power budget to figure out how much you use in a day.

Yes I agree, research in progress, but the best information is from actual usage in the field, or might I say ocean. I think I will be on the higher end of consumption, being land locked for now it will take time to shed my excessive habits, I also read a lot of negative information of wind generators, but I was hoping that some models might be worth it, I guess I will concentrate on solar and go the route of 3 or 4 high amps good quality batteries or lithium.
Thank you, much appreciated.

[Stu Jackson]

You need to begin to understand boat electrical systems, and start with the all important Energy Budget.


These links might help you


Electrical Systems 101 http://c34.org/bbs/index.php/topic,5977.0.html

[cottonsail]

We have 500 watts of solar and 8 Trojan T-105 6 volt deep cycle batteries. We have 3 refrigeration units and an icemaker. The system is self sustaining with full sunshine. Cloudy day's we need the engine's 115 amp alternator. Just our experience.

[Drek4]

Originally Posted by Stu Jackson

You need to begin to understand boat electrical systems, and start with the all important Energy Budget.


These links might help you


Electrical Systems 101 http://c34.org/bbs/index.php/topic,5977.0.html

Thank you so very much for your most valuable reply and links, I will most certainly be going with a 4 battery setup with at least 2x 130/145 watt solar panels as a minimum electrical grid.

[Drek4]

Originally Posted by cottonsail

We have 500 watts of solar and 8 Trojan T-105 6 volt deep cycle batteries. We have 3 refrigeration units and an icemaker. The system is self sustaining with full sunshine. Cloudy day's we need the engine's 115 amp alternator. Just our experience.

I did not expect this, I will be much more attentive with my needed requirements before deciding on my electrical grid setup.
Thank you very much for your input.

[ozdigennaro]

What you do not measure, you cannot control.


Measure consumption (an ammeter at least, but a history-keeping current measure is better).


Measure current production.


People know these are important numbers, bit a bit difficult to keep. I haven't managed it yet.


But these measurements are the key to knowing.

[svfinlandia]

Originally Posted by LoudMusic

At this point nearly everyone agrees wind turbines are useless compared to solar panels.

I guess I am one of those in the minority on wind generators.
When it is cloudy during the day or dark at night my wind generator still continues to put amps in my battery.
Each to his own I suppose, but I love my Kiss wind generator.

Al, S/V Finlandia

[Drek4]

Originally Posted by svfinlandia

I guess I am one of those in the minority on wind generators.
When it is cloudy during the day or dark at night my wind generator still continues to put amps in my battery.
Each to his own I suppose, but I love my Kiss wind generator.

Al, S/V Finlandia

Thank you, would you be so kind to inform me of a link or model of your wind generator, so I could know the capacity, since you seem to have good results with this wind generator?

[sailcrazy]

Let me suggest the first thing you need to do is develop an energy audit for you AND your boat, for a typical day as you plan to use her. It's pretty tough to guesstimate how much battery power (ie, amphours) you need until you know how much you will use in a day. Also, knowing that LA batts should not be discharged below 50%, that gives you a pretty good starting point for how many of what size LA batts you need. Then, where you intend to mount them will also likely play a role in that decision. Once you know how much energy you need to replace on a "typical day", then look at ways to generate those amphrs, ie, genset and batt chgr, main eng altrntr, solar, wind, and/or some combination.
Solar is quiet, but on a sunny day you can expect +/- 20% of rated capacity over the 12hours of sun. Most wind gens don't don't even start to produce until around 10 kts of wind. Here in the Caribb, the trades give that is spades; other places, maybe not so much. And most are some noisy. But...they can generate 24 hrs/day-if the wind is there.
Do you have a genset installed? Or maybe a portable Honda 2000(bring gas!)? Running you main eng, just to recharge the batts, can be done, but that can put a lot of hours on your engine. And while solar is really good, and it's quiet and needs very little attention, you need to have a place where the panels can be mounted. And then there's the controller(s), etc, etc. You're talking about a system, not just a single component, and, in my opinion, it all needs to be looked at as a system....where all the pieces need to be there, need to be mounted and connected, and need to play together. There's a lot to consider, much more than just how many batts do I need. There are lots of forums here you can go back to and read, to give you insight and ideas. There is no "right" answer; every situation is different. And it all costs $$!
As an example, my wife and I live aboard; we rarely go into a marina. We have a genset, 4-120 w panels, a wind gen, and a standard altntr on the eng. We use 6 Trojan T-105 batts (6v, deep cycle) for the house power, and a single standard sealed isolated standard car batt for starting either the genset or the eng. We run our genset about 2 hrs/day...the admiral very much prefers to cook on an elect stove...and our Asia-built boat (230vAC) is built around the genset, with a 230v refer, a 230v watermaker, and the stove. And, of course, we run the batt chgr when the genset is running. We have 675 amphrs installed (new), and try to keep our discharges to 80%-85%, to promote a long life in the batts. so far, after some 23 years on this boat, and cruising now for about 12 years, our system seems to be working OK!

[realem]

Looks like you got some good advice and some ok opinions, The best advice is how much power do you need, and what bad habits do you have. We have 2x100 watt solar and a wind gen. The battery storage is 3x100AH AGM batteries plus a starter battery. We do not have a freezer but do have a fridge which is powered by the solar and the wind generator. Additional power consumption is fans, a water pump. Hot water is off a heat exchanger. We almost never turn on the engine at anchor as our power needs are pretty small. The fridge is the size of a 85 can igloo cooler which we converted into a fridge
Good luck

[Drek4]

Originally Posted by sailcrazy

Let me suggest the first thing you need to do is develop an energy audit for you AND your boat, for atypical day as you plan to use her. It's pretty tough to guesstimate how much battery power (ie, amphours) you need until you know how much you use in a day. Knowing that LA batts should not discharge below 50%, that gives you a pretty good starting point for how many of what size LA batts you need. where you intend to mount them will also likely play a role in that decision. Once you know how much you need to replace on a "typical day", then look at ways to generate those amphrs, ir, genset and batt chgr, main eng altrntr, solar, wind, and/or some combination. Solar is quiet, but on a sunny day you can expect +/- 20% of rated capacity over the 12hours of sun. Most wind gens don't don't even start to produce until around 10 kts of wind. Here in the Caribb, the trades give that is spades; other places, maybe not so much. And most are some noisy. Do you have a genset installed? Or maybe a portable Honda 2000(bring gas!)? Running you main eng, just to recharge the batts, can be done, but that can put a lot of hours on your engine. And while solar is really good, and it's quiet and needs very little attention, you need to have a place where the panels can be mounted. And then there's the controller(s), etc, etc. You're talking about a system, not just a single component, and, in my opinion, it all needs to be looked at as a system....where all the pieces need to be there, and need to play together. There's a lot to consider, much more than just how many batts do I need. and there are lots of forums here you can go back and read, to give you insight and ideas. There is no "right" answer; every situation is different. And it all costs $$!
As an example, my wife and I live aboard; we rarely go into a marina. We have a genset, 4-120 w panels, a wind gen, and a standard altntr on the eng. We use 6 Trojan T-105 batts (6v, deep cycle) for the house power, and a single standard sealed isolated batt for starting either the genset or the eng. We run our genset about 2 hrs/day...the admiral very much prefers to cook on an elect stove...and our Asia-built boat (230vAC) is built around the genset, with a 230v refer, a 230v watermaker, and the stove. And, of course, we run the batt chgr when the genset is running. We have 675 amphrs installed (new), and try to keep our discharges to 80%-85%, to promote a long life in the batts

Thank you that is very valuable information, I would prefer having a 230v system on my boat, since my end game is spending more time in SE Asia, my wife comes from there and I love that area a lot, but I might not be able to obtain a sailboat with this, but this is very useful information that you shared with me.
Much appreciated!