Understanding my solar power and batteries

[StuM]

Originally Posted by Unity

Batteries take higher charge when batteries are less full. For most batteries, above 80% charged is both unnecessary and inefficient. Basically the solar charger will stop sending current (meaning you are wasting available power) as you go to absorb and then even more so at float. Your configuration sounds awesome!

It's only unnecessary if you don't mind killing your large battery bank in a short time.

[motion30]

Originally Posted by ozsailer

G'day Motion,
I would love to know a lot more information if possible.
1) Your current location.
2) Hours of premium sun for highest panel efficiency
3) Type of solar controllers.
4) Did you set the controller for the manufactuers recomended charging rate.
5) Age and size of panels.
6) Are you operating on a 12 or 24 volt system as the theoretcial power current output of the panels is approximately 91 amps at full efficiency. Based on your 360 AH of power being delivered this apears well short of maximum output via the panels unless you have very littel draw down on your batteries daily.
7)What is the current daily power consumption of your vessel.





Greg H

I am in south florida i am using an outback mppt comtroller . my panels are 275watt x4 charging a 12volt system. Like i said eariler I really don't know my consumption. Of course 9 cubic foot 12 volt refrigerator. I am always charging phone batteries by the inverter. I also run a 12-volt 32 inch TV with a kvh satellite system of course not every day and not all day. I run a hundred 10 volt fan in the daytime through the inverter , and a 12 volt fan all night. Of course I have a 12 volt pressure pump for my freshwater, and the jabsco electric toilet that probably gets flushed 10 times a day .My panels are on the roof at the flybridge with absolutely no shading

[motion30]

I may have misspoke I do get into absorption often actually most days. but I do not often get into float of course if I ran the generator for an hour in the morning that certainly helps

[a64pilot]

Well, as much as possible ditch the inverter use and go straight DC.
Your KVH is 12V, but your Sat receiver is most likely 120 VAC only as your TV may be. I bought a small pure sine wave inverter to power our 32” TV and Sat receiver, it’s way more efficient than running the big inverter.
I bought an excellent fan that is actually 24 VDC on Amazon and bought a small 12 to 24 V convertor and it uses less than 1/4 the power of the 120 V fan.
We have a 14 cu ft DC fridge/ freezer.
In other words I bet our consumption is very close.
But your Solar is probably better as I have shading issues you don’t have.

A battery monitor would help you know your consumption, but you can watch your voltage first thing in the morning to tell too. If it’s holding steady, then your replacing what you use, of course if your using more than is going back in, then every morning the voltage will be slightly lower each day as the charge gradually walks down, and that is a battery killer.

In my opinion, do what you can to conserve of course, but your just going to have to accept early morning generator runs of a couple hours, a couple times a week.
Then if possible a monthly equalization charge of the bank will help too, but that pretty much means shore power, cause after your bank is fully 100% charged, it should be allowed to rest a few hours, then of course the equalization phase can be as long as five hours.

When possible I buy a dock for the day myself and maybe even rent a car and bulk provision, buy all the heavy stuff like canned goods etc

[motion30]

actually my Jensen TV and my kvh system are both 12 volts. I have worked very hard to try to keep everything off the inverter

[a64pilot]

Originally Posted by motion30

actually my Jensen TV and my kvh system are both 12 volts. I have worked very hard to try to keep everything off the inverter

You may have one of the older KVH systems then. They had 12V receivers.
The newer ones require a standard Dish or whatever receiver that connects to the KVH receiver, you can’t get away form 120 VAC unless things have changed very recently.
We have a KVH 5.
My Magnum MS 2812 inverter uses I think 20W just being on, so if I can do without it, I do.
I used to just leave the inverter on all of the time, but now I don’t. 20 W isn’t a whole lot, but over a 24 hour period, it adds up.

Any energy intensive things, like for me making water, running the vacuum cleaner, washing clothes, I try to do in the morning when the generator is running.
I have 185 amps of shorepower Charger, so that helps to get a lot of charge into the bank quick.
I have an AGM bank, and that is a lot less tolerant of not being fully charged than your golf cart batteries are.

[Bleemus]

Using an inverter to charge phones is not very efficient. I have one of these that I attach to my start battery which is charged via ACR. Draw is so minimal for phones and tablets it stays fully charged almost always. And the digital voltmeter is a handy quick check.

[motion30]

Bleemus
I like that. I have noticed that shutting my inverter off before I go to bed does save power.
So here is a bit of an update I ran my generator for an hour this morning Comet powers add Magnum inverter that won't charge at 105 amps okay so now at 10:30 I have going into absorption charge at 14.8 volts. I have noticed on a cloudy day when the charging Gets behind a little it takes a days to catch up

[admiralslater]

On the 36 we have 225amps bank made of 2golfcart batteries charged by a 275 watt LG pannel through a victron 100/30 controller. The boat is on a mooring and runs a fridge 24/7. The people I got my equipment from do batteries for fork lifts street signs etc . They even have an all electric Mazda Miata or mx 5 so real battery nerds .
For my applicatiton he suggested equilization every day with the knowledge that on a lot of days I would not get the traditional prograssion to float . He did say watch the water. This has work very well for me . This may help to keep fla batteries in top shape . I change my equaliation routine often based on what the weather is doing . This may not jive with commom practice but for me so far so good

[motion30]

Originally Posted by admiralslater

On the 36 we have 225amps bank made of 2golfcart batteries charged by a 275 watt LG pannel through a victron 100/30 controller. The boat is on a mooring and runs a fridge 24/7. The people I got my equipment from do batteries for fork lifts street signs etc . They even have an all electric Mazda Miata or mx 5 so real battery nerds .
For my applicatiton he suggested equilization every day with the knowledge that on a lot of days I would not get the traditional prograssion to float . He did say watch the water. This has work very well for me . This may help to keep fla batteries in top shape . I change my equaliation routine often based on what the weather is doing . This may not jive with commom practice but for me so far so good

How are you getting to Equalization voltage? A generator?

[admiralslater]

Originally Posted by motion30

How are you getting to Equalization voltage? A generator?

Strictly solar ,and I have seen it in action via voltmeter .the batteries are nice and high with less water usage than expected. If you have great sun every day you may want to tailor the frequency of charge.

[Cadence]

Originally Posted by motion30

I am in south florida i am using an outback mppt comtroller . my panels are 275watt x4 charging a 12volt system. Like i said eariler I really don't know my consumption. Of course 9 cubic foot 12 volt refrigerator. I am always charging phone batteries by the inverter. I also run a 12-volt 32 inch TV with a kvh satellite system of course not every day and not all day. I run a hundred 10 volt fan in the daytime through the inverter , and a 12 volt fan all night. Of course I have a 12 volt pressure pump for my freshwater, and the jabsco electric toilet that probably gets flushed 10 times a day .My panels are on the roof at the flybridge with absolutely no shading

I was going to approach that at the risk of sounding stupid. It would seem trimming consumption may solve the situation. Reducing bank size would only make it worse.

[a64pilot]

Originally Posted by Cadence

I was going to approach that at the risk of sounding stupid. It would seem trimming consumption may solve the situation. Reducing bank size would only make it worse.

Decrease consumption, or increase production, or shoot for both.
End result is similar
However it ignores one real issue, and that is that there is often simply just not enough Solar hours in the day to get to a full, 100% charge.
It can take up to seven hours to charge a bank fully, the last couple only adding in a few percent, but you have on average only about five and a half hours of Solar a day.
You can of course go on for a long time only recharging your bank in the 90’s percent charge, and most who live on Solar do.
However the bank may live longer if it’s regularly fully charged and equalized.

In my case, I early on accepted that I would need a generator, and included it in my electrical plan, it drove which Watermaker I bought and whether or not we have a clothes washing machine etc. which also drove which Watermaker, cause a clothes washer goes though an enormous amount of water. One wouldn’t be viable in my opinion without a Watermaker.

[Rorzech]

When you say you have 1300 Ah of Golfcart Batteries, Is that 1,300 Ah @ 6 Volts ? Did you read the Ah on one battery and multiply that by number of batteries. Very common mistake. You would need 20 130Ah 6V batteries to make 1,300 Ah @ 13 volts. That's a lot of batteries. I would say, get more solar panels. Then you could make more power when it's cloudy. There's no such thing as having too many solar panels, unless they start to sink your boat of course. But that's just me.

[motion30]

I have 12. X215 amp batteries. 1290 amps. Check my math. No?