Charging batteries from solar panels?

[suiramor]

I have a Freedom Marine 20 to charge my batteries (700Ah house and 100Ah engine). Can I connect my solar panel control output directly to the house battery terminals or must this power somehow go through the controller? If so, how? (My solar produces max 10A at this time, i am planning to add more panels to get to 20A on a sunny day).

[SailingHarmonie]

Your solar controller connects to the batteries, it does NOT go through the existing battery charger.

It would best connect to the bus bars, NOT “directly to the batteries.” Your controller should have a manual showing you how to make this work.

[suiramor]

Thanks @SailingHarmonie. My manual has nothing about 'battery bars' though. (It does have a strong warning about connecting panels to controller without it being connected to batteries but that's not my issue). What's wrong with connecting controller directly to the battery terminals, which in turn are connected in parallel with other batteries?

[suiramor]

Manual: Adventurer 30A PWM

[leecea]

I was curious about the buss bar as I'm trying to learn this stuff myself. I found a slide deck that says you don't connect the negative to the battery if you have a battery monitor - it's page 20

https://www.custommarineproducts.com...m_-_wiring.pdf

[George_SD]

You do need a controller. I went with a cheap PWM Wonderer controller that connects directly to the power bank. Works great and has a USB port to charge mobile devices from the solar. I have a single 100w panel that charges multiple lead acid FLA batteries. I don't even plugin the boat at the slip...
However, given your larger bank - go with a MPPT (more efficient, better charging).

[SailingHarmonie]

Originally Posted by suiramor

Thanks @SailingHarmonie. My manual has nothing about 'battery bars' though. (It does have a strong warning about connecting panels to controller without it being connected to batteries but that's not my issue). What's wrong with connecting controller directly to the battery terminals, which in turn are connected in parallel with other batteries?

First, read and understand this: https://fetchinketch.net/boat_though...y-connections/ If you understand the why of that, you'll see the issue with connecting a charging source to one set of battery terminals.

I assume you have a battery monitor of some sort that give you a readout of your batteries state of charge? If you do, and you connect your solar system directly to the batteries you bypass the measuring system.

Finally, connecting connections directly to the batteries is messy, and results in hard to diagnose problems. For example, where are you going to put the fuse?

When you are doing electrical work neatness counts.

[suiramor]

Thanks again @SailingHarmonie. Yes, I never considered that some batteries are more equal than others even in a parallel connection. I will explore my setup to address this. To not bypass my current measuring system, I will need to figure out where to connect my controller output so it is seen by my battery monitor. AFAIK, that one (Link2000) gets its input from the charger/inverter (Freedom Marine 20) via a phone cable. I don't see options on either to receive input from the solar controller. However, the latter does display its status so perhaps the only issue will be having two independent monitors to watch: one for regular charging and one for solar.

[SailingHarmonie]

Originally Posted by suiramor

Thanks again @SailingHarmonie. Yes, I never considered that some batteries are more equal than others even in a parallel connection. I will explore my setup to address this. To not bypass my current measuring system, I will need to figure out where to connect my controller output so it is seen by my battery monitor. AFAIK, that one (Link2000) gets its input from the charger/inverter (Freedom Marine 20) via a phone cable. I don't see options on either to receive input from the solar controller. However, the latter does display its status so perhaps the only issue will be having two independent monitors to watch: one for regular charging and one for solar.

We are really getting down to some very basic stuff here that you just do not know. Short of writing a book, I can't get you to where you need to be to do this on your own safely and correctly. This just isn't the place to learn EVERYTHING about marine electrics.

I strongly suggest that you work with a marine electrician who can help you sort this out. Or buy the book.

[Uncle Bob]

^^^^^^
Truly excellent advice.

[suiramor]

While gratefully accepted, your latest seems like a non sequitur kind of response (and probably could be given to any question posted here): I think I understood and acknowledged your comment and link re how to physically connect DC inputs to the existing battery bank. My remaining unknown is re potential issues with monitoring solar and charger input separately seems like anything but basic but I think I am happy to live with that as all missing from knowing EVEYTHING. Thanks again.

[fxykty]

Originally Posted by suiramor

While gratefully accepted, your latest seems like a non sequitur kind of response (and probably could be given to any question posted here): I think I understood and acknowledged your comment and link re how to physically connect DC inputs to the existing battery bank. My remaining unknown is re potential issues with monitoring solar and charger input separately seems like anything but basic but I think I am happy to live with that as all missing from knowing EVEYTHING. Thanks again.

I think the other poster’s issue is that your questions are very basic and show that you don’t have much DC electrical knowledge. That’s OK, everyone starts somewhere. But if you connect things up incorrectly or poorly you risk fire and possibly shock hazards, and damaging/destroying equipment or battery.

Regarding your battery monitor, it doesn’t care about monitoring or reporting the solar charging. But it will report on total charge current going into the battery (which should include the solar charging current) and it will report on load current coming out of the battery (say if your load is greater than the amount of solar charging you have going on.

Bus bars are a very basic concept that are used when you have too many wires to connect to a single battery terminal, which is typically the case with a boat (but not a car, no bus bars there, though you will likely have a terminal box for all the lights, etc., and that’s a type of bus bar too.

You have a positive bus which connects to your battery’s positive terminal. Your shore power charger positive output, solar controller positive output, inverter positive input, DC switching positive input, and all other major positive wires connect to the positive bus. Each wire leaving the positive bus should be appropriately fused.

You may have a on/off or one, two, all, none switch between your battery terminal and the positive bus. There should also be a fuse on the positive wire as close as possible to the battery positive terminal.

Your negative bus will connect to the negative shunt (that’s how your battery monitor knows what’s going on), which will in turn be connected to the battery negative terminal. The negative bus will have the same number of wires as the positive bus, since every positive needs a negative to complete the circuit.

Your posts were unclear whether you’ve got a solar controller or not. You should not connect the output wires of a solar panel directly to a battery or bus; the panel(s) should be connected to a solar controller, which is then connected to your positive and negative busses. Without a controller you can’t be sure that the output voltage of the solar panel matches that of your battery - a 12V panel for example outputs at below 12V at low solar insolation times and well above 12V on a very cold and sunny day. A controller smooths all that out to provide your battery with the charge voltage you need.

[davil]

Originally Posted by fxykty

I think the other poster’s issue is that your questions are very basic and show that you don’t have much DC electrical knowledge. That’s OK, everyone starts somewhere. But if you connect things up incorrectly or poorly you risk fire and possibly shock hazards, and damaging/destroying equipment or battery.

Regarding your battery monitor, it doesn’t care about monitoring or reporting the solar charging. But it will report on total charge current going into the battery (which should include the solar charging current) and it will report on load current coming out of the battery (say if your load is greater than the amount of solar charging you have going on.

Bus bars are a very basic concept that are used when you have too many wires to connect to a single battery terminal, which is typically the case with a boat (but not a car, no bus bars there, though you will likely have a terminal box for all the lights, etc., and that’s a type of bus bar too.

You have a positive bus which connects to your battery’s positive terminal. Your shore power charger positive output, solar controller positive output, inverter positive input, DC switching positive input, and all other major positive wires connect to the positive bus. Each wire leaving the positive bus should be appropriately fused.

You may have a on/off or one, two, all, none switch between your battery terminal and the positive bus. There should also be a fuse on the positive wire as close as possible to the battery positive terminal.

Your negative bus will connect to the negative shunt (that’s how your battery monitor knows what’s going on), which will in turn be connected to the battery negative terminal. The negative bus will have the same number of wires as the positive bus, since every positive needs a negative to complete the circuit.

Your posts were unclear whether you’ve got a solar controller or not. You should not connect the output wires of a solar panel directly to a battery or bus; the panel(s) should be connected to a solar controller, which is then connected to your positive and negative busses. Without a controller you can’t be sure that the output voltage of the solar panel matches that of your battery - a 12V panel for example outputs at below 12V at low solar insolation times and well above 12V on a very cold and sunny day. A controller smooths all that out to provide your battery with the charge voltage you need.

[suiramor]

Thanks @fxykty. Yes, I am now clear on the bus connections and related items (switches and fuses). My solar input is coming through a controller. I mentioned it in my 2nd and 3rd reply (Adventurer 30A PWM).

[Stu Jackson]

Originally Posted by suiramor

................


To not bypass my current measuring system, I will need to figure out where to connect my controller output so it is seen by my battery monitor. AFAIK, that one (Link2000) gets its input from the charger/inverter (Freedom Marine 20) via a phone cable. I don't see options on either to receive input from the solar controller. However, the latter does display its status so perhaps the only issue will be having two independent monitors to watch: one for regular charging and one for solar.

I have had my Link 2000 for 20 years. What you describe as the phone cable is actually called the Inverter Remote Cable in the manual. It has NOTHING to do with the Link measuring battery system amperage, it is only used to turn the inverter and charger on or off from the face of the Link. Please, just forget about it in terms of your question.

Those who have mentioned your need to better understand your electrical system (without having to write a book ) may not be too far from wrong.

REGARDLESS of the source of the input charge, the SHUNT measures incoming and outgoing amps for the Link. These wires are independent of the phone cable which again has nothing to do with the charging or discharging amps.

You simply connect the solar to the solar controller and connect the controller to your house bank. Others have commented on how to do this.

If you don't have the manual for your Link, you can find one online at Xantrex's website under discontinued products. The manual is also applicable for the older Heart Link units because Xantrex bought them out and changed nothing except the faceplate label.

You may also be interested in these links which discuss how to best use your Link 2000. Good luck.

The "Gotcha Algorithm" thread, a "MUST READ"

http://c34.org/bbs/index.php/topic,4922.0.html

DEFAULTS are factory settings that are made to be modified to suit your setup.

Also read this one:

Programming a Battery Monitor (by Maine Sail)

https://marinehowto.com/programming-a-battery-monitor/