Jump to content
Vivaldi

Solar panel doesn’t appear to be charging.

Recommended Posts

Zozza, looking at the GoFlex website they seem to be around 9v nominal voltage, is that right?

 

https://goflexsolar.co.nz/ourproducts/

 

Correct, Grant.  I needed to get a MPPT with a 'booster' due to only being 9v nominal panels, so I got three of these (I chose to have one controller for each panel to have contingency) : 

https://sunforgellc.com/gvb-8/

 

Apparently, being 9v panels is why they (GoFlex) can get away with such "skinny" 50w panels (which I needed for my small yacht with not much deck or cabin-top space).  Don't quote me on that, as I what I know about electrical stuff you could fit on your fingernail.

 

Back on Genasun controllers: I am not a rich man, but I didn't want to skip on getting cheap sh#t when it came to my solar set up, especially the controllers, and if you do your research then you will find nothing but good words about their controllers - great customer service too...they answer emails promptly, and ship your order from the States equally promptly.  I'm so used to sh#t service from Marine industry that I always shout out a company that is good.

Share this post


Link to post
Share on other sites

How does it work having 3 controllers on the one battery bank work?

In my limited knowledge, I thought only the highest voltage charges the battery, and to accumulate the current from the 3 different panels you need to run them through a single controller?

Although I could be wrong, I've never investigated multiple controllers.

Share this post


Link to post
Share on other sites

How does it work having 3 controllers on the one battery bank work?

In my limited knowledge, I thought only the highest voltage charges the battery, and to accumulate the current from the 3 different panels you need to run them through a single controller?

Although I could be wrong, I've never investigated multiple controllers.

 

Dunno Fish, but it works.  What I can say is batteries are wired in parallel.  A marine electrician wired it all up for me, and when I flick the switch everything works as it should.

Need someone like Wheels or Matt to educate us on how this all works.

Share this post


Link to post
Share on other sites

If the settings for each device is the same or similar, then simply they will all work together within their own ratings and until they reach the limit of their settings.  Very rarely will you find conflict from multiple charge sources,  but technically you can get a drop in efficiency.  

Share this post


Link to post
Share on other sites

We have a juice panel. Junction box on panel corroded after about 5 months use. We had to send our panel back to them they fixed it and sent it back. Was a pain to do but at least we eventually got a working panel again. I think its been up 7 months now and still working so fingers crossed.

Share this post


Link to post
Share on other sites

OK, the multiple controllers/regulators/sources for one bank discussion.

 

1st how the regulators (multi stage, smart type) charge controllers work is basically like this;

 

They begin with Bulk charge mode. The controller pushes in as many amps as it can, and the voltage rises to the set max (say for example 14.6v) when this voltage is reached, the batt is commonly about 80% charged. 

Then, the controller/regulator switches to Absorbtion mode - the voltage is held steady at the set voltage (normally the same as bulk, using our 14.6v example)  The current (in AMPS) drops away as the batts become charged, and they accept less and less current. This is a slow process, and depends on batt type how long it takes. Some chargers just do this for a set time, better ones can monitor the current, and when it drops to a set percentage of capacity (often 1-2%) they then drop to float mode.

Float mode is what voltage batteries are kept at to keep them full. Its often around 13.6 - 13.8v, but read your batts PDS to find out exactly what it should be!

 

So, that's a single regulator/controller.

 

If you have multiple controllers, except for some very top end ones that can communicate with each other, this is what happens;

 

All the controllers start and try to push the voltage up to the set max (Bulk rate).

Once they get to their set rate they will stop charging if one of the others is set slightly higher. So the charger with the highest settings will finish the charging from there. This can waste quite a bit of time and resource with solar, as often an array cannot provide all the current that a battery will accept in Absorb mode, especially if its later in the day, cloudy, etc.

However if the current that could be accepted is not provided, then the voltage usually drops a bit, and the 2nd highest set controller may take over. This often happens on a boat with arrays that are shaded differently.

There is another point to consider. Most controllers will try to charge to bulk every day. Absorbtion duration is often just time, not current, so in theory you could have one array in the sun, starts, gets thru bulk to absorbtion, gets shaded, other panel then in the sun starts, quickly gets bulk voltage, switches to absorbtion... so your batts spend too much time at the high absorbtion voltage, and prematurely fail.

 

Smarter controllers are becoming available. I've just installed one on my alternator - it uses the battery computer shunt so it knows what the batts are accepting, and changes quickly to float voltages if the accepted current is low (settable, I use 4 amps on a 400 Ahr bank). I've only found one issue with this so far, and that is that if the battery is discharging, (like the microwave is on) the controller thinks thats less than 4a, and switches to float voltage, right when I'd like it to be as high as possible. I'm working on that with the designer....

 

I hope that is helpful to some.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...