Troubleshooting Solar 400W (4x100W) + Victron

[Cloroxbottle]

I was wondering if I could get a little advice on what to try next.

The solar on our boat has never worked all that well. It never bothered me much because we strictly daysailed for the most part and were in a marina otherwise.

However now, we are considering some longer trips and spending time at anchor or on mooring balls so it has gone from an after thought to mission critical.

I got out my ammeter and tested several of the panels, two were shot. Replaced them and now have four good panels wired in parallel each with set of two connected to a Victron 75/15 MPPT charge controller I've used my ammeter to trace good output with the amps adding together as far as the input plugs of the MPPTs.

The way the previous owner seems to have wired it is to attach the output wires for each charge controller to posts on the Victron Pallas battery charger along with the. Battery leads.

While shore power and the alternator charge correctly, regardless of the state of discharge of the battery bank I can't get more than maybe 5 amps out of a solar array that should be able to generate four times that based on its specs.

Thoughts?

[Uncle Bob]

Originally Posted by Cloroxbottle

I was wondering if I could get a little advice on what to try next.

The solar on our boat has never worked all that well. It never bothered me much because we strictly daysailed for the most part and were in a marina otherwise.

However now, we are considering some longer trips and spending time at anchor or on mooring balls so it has gone from an after thought to mission critical.

I got out my ammeter and tested several of the panels, two were shot. Replaced them and now have four good panels wired in parallel each with set of two connected to a Victron 75/15 MPPT charge controller I've used my ammeter to trace good output with the amps adding together as far as the input plugs of the MPPTs.

The way the previous owner seems to have wired it is to attach the output wires for each charge controller to posts on the Victron Pallas battery charger along with the. Battery leads.

While shore power and the alternator charge correctly, regardless of the state of discharge of the battery bank I can't get more than maybe 5 amps out of a solar array that should be able to generate four times that based on its specs.

Thoughts?

No expert but I installed 190 watts of panels with a pwm controller some years ago, panels in parallel to controller to battery with fuse at battery. A week ago panels were producing 12 amps immediately after running an electric polisher via an inverter for an hour. Two days ago they were producing 7.6 amps sailing while running instruments, plotter, autopilot and fridge.
Perhaps try connecting controller output direct to batteries, fused of course, and remeasure the output.
Good luck, I agree that they should be much more productive.

[boatpoker]

Why on earth would anyone run solar through a battery charger ?

[Jim Cate]

Originally Posted by boatpoker

Why on earth would anyone run solar through a battery charger ?

I think he means that he joins the output of the MPPT to the output side of the charger, and those leads go directly to the battery. Not elegant, but should work if the cable size is appropriate.

Now, for the OP: have you recently checked each panel in full sun for open circuit voltage and short circuit current? That is a simple test that does not require sophisticated equipment... just a decent DVM that can measure the full output current of a panel. If it does not equal that shown on the panel's label, it could well be the panels that are the problem after all.

And the anemic output that you have measured... I dunno where you are, but if in the N hemisphere, and especially if a bit removed from the equator, your sun angles are at their lowest of the year. If your panels are horizontal, they will not get close to their theoretical output for that requires the incoming sunlight to be at right angles to the panel's surface.



Jim

[newhaul]

Originally Posted by Cloroxbottle

I was wondering if I could get a little advice on what to try next.

The solar on our boat has never worked all that well. It never bothered me much because we strictly daysailed for the most part and were in a marina otherwise.

However now, we are considering some longer trips and spending time at anchor or on mooring balls so it has gone from an after thought to mission critical.

I got out my ammeter and tested several of the panels, two were shot. Replaced them and now have four good panels wired in parallel each with set of two connected to a Victron 75/15 MPPT charge controller I've used my ammeter to trace good output with the amps adding together as far as the input plugs of the MPPTs.

The way the previous owner seems to have wired it is to attach the output wires for each charge controller to posts on the Victron Pallas battery charger along with the. Battery leads.

While shore power and the alternator charge correctly, regardless of the state of discharge of the battery bank I can't get more than maybe 5 amps out of a solar array that should be able to generate four times that based on its specs.

Thoughts?

What is the state of charge of the battery?
Place a significant load on them and test panel output with the load energized

[smac999]

are you getting even current on each panel? like 1.5a?

and even on both controller wires to battery? 2.5a each?

or is one good and one bad?... or they all bad?...

note the panel current and battery current will not match as the panels are higher voltage. but all 4 inputs should be simular and 2 outputs should be simular to each other.

this is where the bluetooth controllers are really nice as you can see all kinds of info.

what is the panel voltage and the battery voltage measued at each controller?

what is the load wire going to?... that's not really used on boats.


and as above. make sure the batteries are drained or have a load bigger then 400w when testing.

joing to the charger is cheap but should not be what's causing the issue.

[noelex 77]

What are the red and yellow load leads that are shown in the photo connected to?

As Jim noted, connecting the solar output to the output of the battery charger, while not ideal will still work, but the photo of the battery charger shows only one set of leads connected to the output of the battery charger. The output of the battery charger also needs a connection to the battery for the system to work and it not clear how this is achieved.

[DefinitelyMe]

Yes your setup should work, and you should get much more than 5A. Test under load (with shore power turned off) so that charging is in bulk stage. Verify no shading of panels. If still no joy my next step would be to start simplifying things and testing systems independently. E.g. connect outputs directly to batteries, take one regulator offline etc.

We are at 32N latitude at the moment and getting high teens output from 400W around mid-day.

[sailorboy1]

Is that only 5 amps with shore power off, .......... right?

[tarian]

The victron 75/15 will handle 245 Watts of solar on 12v and 440 Watts on 24v system if loads are exceeded the mppt will not function to full efficency

[Cowpoos]

Originally Posted by Cloroxbottle

I was wondering if I could get a little advice on what to try next.

The solar on our boat has never worked all that well. It never bothered me much because we strictly daysailed for the most part and were in a marina otherwise.

However now, we are considering some longer trips and spending time at anchor or on mooring balls so it has gone from an after thought to mission critical.

I got out my ammeter and tested several of the panels, two were shot. Replaced them and now have four good panels wired in parallel each with set of two connected to a Victron 75/15 MPPT charge controller I've used my ammeter to trace good output with the amps adding together as far as the input plugs of the MPPTs.

The way the previous owner seems to have wired it is to attach the output wires for each charge controller to posts on the Victron Pallas battery charger along with the. Battery leads.

While shore power and the alternator charge correctly, regardless of the state of discharge of the battery bank I can't get more than maybe 5 amps out of a solar array that should be able to generate four times that based on its specs.

Thoughts?

What is the voltage of your system? and second can you show a picture of your solar panels? I suspect a shading issue.

[mitiempo]

To start I would remove the load wires from the Victron solar controllers - not commonly used on a boat.

I would wire the controller output to either the battery bank directly or the charge bus if there is one. I also not there are only one set of wires connected to the battery charger - where are the solar wires connected?

I would then go back to the panels and confirm they are wired properly with a multimeter. Positive to positive and negative to negative and then to the controller - make sure the connections are good.

Then test again.

[BruceS]

Not the first time I've also seen people try to get output on those useless "load" terminals.

[tarian]

Please read your victron mppt 75/15 victron instruction booklet , available on the inter web , it clearly states if loads are exceeded via solar to mppt you will have issues . 400 w of solar at 12 v does not go into 220 watts of maximum load for this mppt , you will need to upgrade your mppt for the loads your solar is putting out which is 400 watts
2 x parallel solar 2x100 x2 still gives yous 400w forget about amperage this is after the mppt converts watts. To amps 400 w does not go into 220 w which is the maximum load a victron 75/15 mppt will accept ,which may cause damage to your mppt and solar

[noelex 77]

Originally Posted by tarian

2 x parallel solar 2x100 x2 still gives yous 400w forget about amperage this is after the mppt converts watts. To amps 400 w does not go into 220 w which is the maximum load a victron 75/15 mppt will accept ,which may cause damage to your mppt and solar

The OP has 2x Victron 75/15 so each unit has a solar input of 200w.