Solar panel regulator

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Graham_Wright

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www.mastaclimba.com
I have two, one 10A the other 20A. The accompanying literature is in chinglish and worst than most.

What do I do with the "load" outputs?

To avoid confusion (which I seem to have caused!), there are six terminals on the front. Two from the panel, two to the battery and two labelled "load". My question relates to the latter.

(Why don't the Chinese, after developing a probably good product, spend a few quids on employing a decent translator for a day?)
 
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OKi So my setup is two cables positive and negative from the solar panel into the controller you might see an icon representing the solar panel. And then negative from controller to negative house battery and the positive runs to a blade fuse with another positive off the same blade fuse running to the positive house battery terminal.
I then power a blue sea fuse block (switch panel if preferred) from the house battery via a battery switch.

There are plenty of how to videos on YouTube just not always listed under boating specific but the concept is the same
 
Graham_Wright said:
What do I do with the "load" outputs?
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Just ignore them.

It is not required to use the load outputs and with their limited current capacity they are not much use on a boat. On some solar regulators the load outputs can be configured to act as day/night switch (for the anchor light) or a low voltage switch (perhaps for the fridge). Some are even smarter and can be programmed, for example, to turn on a device for 1hr if he regulator is in the float stage (perhaps for fuel polishing), but most people do not bother with these complications and leave the load outputs unconnected.
 
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On some the load is a separate connector for instant power other than what's going to the batteries. Mine powers a 12volt socket that runs a cool box only when the panel has spare capacity to do so.
Again on mine, you have a picture of the panel, battery and light bulb which I use for load.
 
I'll try the "load" output to the fridge. Mine is a complex system;- two alternators, two 100W panels three batteries. I will arrange series/parallel switching.

I am trying to cater for the situation where one panel is shaded the other not so the switchery is looking "interesting"!
 
To combat shading connect your panels in parallel - simples!

I do nothing with my load output - all seems a bit complicated.

I think, (and that's all), if you connect something to the load output it will use solar power when available, and battery power when it isn't. I dont pretend to understand how it decides what to do... I feel more comfortable with things powered from the batteries and nothing else.
 
Graham_Wright said:
I'll try the "load" output to the fridge. Mine is a complex system;- two alternators, two 100W panels three batteries. I will arrange series/parallel switching.

I am trying to cater for the situation where one panel is shaded the other not so the switchery is looking "interesting"!
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Don't. Connect the controller to the domestic bank and forget the load terminals.

Do you have three batteries, or three banks ?

How are you connecting the controllers to the batteries ?

How do the alternators connect ?
 
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Richard10002 said:
I think, (and that's all), if you connect something to the load output it will use solar power when available, and battery power when it isn't. I dont pretend to understand how it decides what to do... I feel more comfortable with things powered from the batteries and nothing else.
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It does not make any difference to the batteries if a device is connected to the load outputs or directly to the battery (ignoring any slight voltage drop) other than the load output can, on some solar regulators, be programmed to do things such as cut out below a certain voltage. The battery is not cycled less because you have connected to load terminals.

If you are connecting to the load terminals, keep in mind that the current output is limited (usually, but not always to the same current as the rating of the regulator).
 
PaulRainbow said:
Don't. Why not? If the load output fires up when the batteries are full, and, if the available "load" current is sufficient to drive the fridge, why waste it?

Connect the controller to the domestic bank and forget the load terminals. ​Do you have three batteries, or three banks ?Two controllers three batteries (not banks, if that makes any difference).



How are you connecting the controllers to the batteries ? Probably via diodes to allow mixing sources. (Like my camper van, one panel, three batteries, one alternator, mains charger, load output trickle (?) charges starter battery).

How do the alternators connect ? Diodes.
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Graham_Wright said:
Why not? If the load output fires up when the batteries are full, and, if the available "load" current is sufficient to drive the fridge, why waste it?
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The output from the solar panels is not wasted even if the load is connected to the batteries and not to the load terminals.

If there is additional load (such as the fridge starting) and the batteties are full with the solar regulator is in float, the regulator will allow more current (if the panels can produce this current) to compensate for the fridge draw in order to maintain the same float voltage (say 13.8V).

It makes no difference to the power output of the solar panels, or the draw on the batteries if the fridge is connected to the load terminals or directly to the battery. The only exception is if you engage the low voltage cut out feature of the load terminals. In this case, the fridge will turn off if it is connected to load terminals and the battery voltage drops to a low level (usually around 11.9V).
 
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Graham_Wright said:
Don't. Why not? If the load output fires up when the batteries are full, and, if the available "load" current is sufficient to drive the fridge, why waste it?
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As Noelex said.

Connect the controller to the domestic bank and forget the load terminals. ​Do you have three batteries, or three banks ?Two controllers three batteries (not banks, if that makes any difference).
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It does make a difference. If the batteries are one for the engine and the other two connected together for the domestics, that's two banks, matters not how many batteries are in a bank (for the purposes of this thread). If this is the case there is no need to use two controllers, just connect the two panels to the 20a controller and then to the domestic bank (same terminals that the domestic loads are connected to). You can experiment between series and parallel connection, but if you have shading concerns you may well find parallel works best.

How are you connecting the controllers to the batteries ? Probably via diodes to allow mixing sources. (Like my camper van, one panel, three batteries, one alternator, mains charger, load output trickle (?) charges starter battery).


How do the alternators connect ? Diodes.
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I'd avoid diodes, due to the voltage drop. If you want to charge the engine battery from the solar panels you could fit a VSR. One option would be to fit a VSR between the engine and domestic banks, if this was dual sensing then you could get rid of the diodes currently fitted to the alternator outputs, connect the smaller alternator to the engine battery and the other one to the domestic bank. This would mean that all alternator output is available to all batteries, the engine battery will charge quickly, leaving both alternators charging the domestic bank. It also means that the solar panels will be charging all batteries, keeping the engine battery topped up. An additional bonus will be that you won't have the voltage losses that you currently have with the diodes.

You could also replace the diodes with low loss splitters, such as the Victron FET based splitters (or other makes of similar devices). But that will cost more and won't allow the solar panels to charge the engine batteries.

The other solution would be to leave the alternator charging as it is, if you're happy how it works and don't mind the voltage drops, and just connect the solar controller to the domestic bank, leaving the engine battery to fend for itself. This is usually OK unless you leave the boat unattended for long periods and have a way of starting the engine from the domestic bank, which you should have anyway.

Either way, if the battery configuration is a single battery for the engine and two domestic batteries connected together, using two panels with two controllers, connected to the domestic bank, is asking for trouble. Getting them to work together without one shutting down when it detects the voltage from the other controller can be an issue and it's an issue that you don't need. Your two panels will work just as well connected to a single controller.
 
PaulRainbow said:
[/COLOR]As Noelex said.



[/COLOR]It does make a difference. If the batteries are one for the engine and the other two connected together for the domestics, that's two banks, matters not how many batteries are in a bank (for the purposes of this thread). If this is the case there is no need to use two controllers, just connect the two panels to the 20a controller and then to the domestic bank (same terminals that the domestic loads are connected to). You can experiment between series and parallel connection, but if you have shading concerns you may well find parallel works best.




I'd avoid diodes, due to the voltage drop. If you want to charge the engine battery from the solar panels you could fit a VSR. One option would be to fit a VSR between the engine and domestic banks, if this was dual sensing then you could get rid of the diodes currently fitted to the alternator outputs, connect the smaller alternator to the engine battery and the other one to the domestic bank. This would mean that all alternator output is available to all batteries, the engine battery will charge quickly, leaving both alternators charging the domestic bank. It also means that the solar panels will be charging all batteries, keeping the engine battery topped up. An additional bonus will be that you won't have the voltage losses that you currently have with the diodes.

You could also replace the diodes with low loss splitters, such as the Victron FET based splitters (or other makes of similar devices). But that will cost more and won't allow the solar panels to charge the engine batteries.

The other solution would be to leave the alternator charging as it is, if you're happy how it works and don't mind the voltage drops, and just connect the solar controller to the domestic bank, leaving the engine battery to fend for itself. This is usually OK unless you leave the boat unattended for long periods and have a way of starting the engine from the domestic bank, which you should have anyway.

Either way, if the battery configuration is a single battery for the engine and two domestic batteries connected together, using two panels with two controllers, connected to the domestic bank, is asking for trouble. Getting them to work together without one shutting down when it detects the voltage from the other controller can be an issue and it's an issue that you don't need. Your two panels will work just as well connected to a single controller.
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The small alternator charges the engine battery only. The Prestolite 130A alternator charges the two house batteries via a diode splitter. This alternator has adjustable output (and could be remote sensed but that gets messy with a split charge). The two panels can be switched between either house battery. When the panels are paralleled, they will be on one controller and the output can go to either one house battery or both. When the panels rare series connected, they will feed through one controller and then feed either battery or both.

I like redundancy!
 
Graham_Wright said:
The small alternator charges the engine battery only. The Prestolite 130A alternator charges the two house batteries via a diode splitter. This alternator has adjustable output (and could be remote sensed but that gets messy with a split charge). The two panels can be switched between either house battery. When the panels are paralleled, they will be on one controller and the output can go to either one house battery or both. When the panels rare series connected, they will feed through one controller and then feed either battery or both.

I like redundancy!
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Not sure how you have the domestic batteries connected for things to work like that. They must be separate, rather than connected together in parallel ?

I also like redundancy Graham, but that sounds a little more complicated than it needs to be.
 
PaulRainbow said:
Not sure how you have the domestic batteries connected for things to work like that. They must be separate, rather than connected together in parallel ?
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The house batteries rare separate. I have two feeds to my distribution board, one from each battery. I then have four groups of breakers supplying lights, radios, and "always on" instruments, pumps etc. Each group can be switched to either battery.

I tried to use a rotary switch to select the various combinations but it was messy and have ended with simple toggle switches. Using diodes, it is easy to mix and match. It works well on the camper with a similar choice of sources.

I also like redundancy Graham, but that sounds a little more complicated than it needs to be.
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I reached that conclusion years ago and wonder how many years it has cost me. Beyond cure sadly.:nonchalance:
 
Graham_Wright said:
The house batteries rare separate. I have two feeds to my distribution board, one from each battery. I then have four groups of breakers supplying lights, radios, and "always on" instruments, pumps etc. Each group can be switched to either battery.

I tried to use a rotary switch to select the various combinations but it was messy and have ended with simple toggle switches. Using diodes, it is easy to mix and match. It works well on the camper with a similar choice of sources.



I reached that conclusion years ago and wonder how many years it has cost me. Beyond cure sadly.:nonchalance:
Click to expand...

Definitely more complicated than it needs to be, but makes more sense now that i know the domestic batteries are separate :)

You could simplify and improve the charging a little without upsetting the rest or costing much. I wouldn't worry about switching the panels between series and parallel connections, pick one and stick with it, any chance of shading and i'd go for parallel connection. I'd connect both panels to the 20a controller and connect that to one domestic battery. Put a VSR between the domestic batteries and the panels will charge both batteries. You can then remove the diode from the Prestolite connection and it too will still charge both batteries. You could then fit the diode to the smaller alternator, connecting it to both the engine battery and one domestic battery, thus getting charge into all batteries from both alternators with the engine running and getting rid of the voltage loss with the diode connected to the Prestolite.
 
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