Do these figures look right on my solar set up?

[yossarian]

Assuming this is your panel: https://www.enfsolar.com/pv/panel-datasheet/crystalline/44126, the numbers look ok for a 48 cell panel suggesting a high resistance somewhere in the panel or perhaps between panel and victron.

 

[RockinNRollin]

@Peter84 if your installation is fairly new I’d be in contact with the installers and let them diagnose it. It’s certainly not right anyway - in direct sun close to perpendicular to the panel I’d expect at least 80-90% of the panel max output.

 

[Peter84]

@yossarian that’s the one.

 

[Barry Chuckle]

@yossarian that’s the one.

I've checked mine too, I've 115w solar and I've not had more than 50w ever out of mine either even in the sunlight we've enjoyed these past few days.

Would it be right the solar panels don't 'pull' more than they need to if the leisure batteries are fully charged?

 

[RockinNRollin]

I've checked mine too, I've 115w solar and I've not had more than 50w ever out of mine either even in the sunlight we've enjoyed these past few days.

Would it be right the solar panels don't 'pull' more than they need to if the leisure batteries are fully charged?

Once on float, yes that’s right - they just pull what they need. On bulk though they should be putting out everything they can get.

 

[Barry Chuckle]

Once on float, yes that’s right - they just pull what they need. On bulk though they should be putting out everything they can get.

Sorry excuse my useless practical knowledge what's the difference between bulk and float?

 

[RockinNRollin]

Sorry excuse my useless practical knowledge what's the difference between bulk and float

Essentially float is when the batteries are full and it’s the necessary output from the controller to keep them topped off, bulk is when the batteries are depleted by pretty much anything and the controller is pumping in everything it can, while absorption is sort of a tapering between bulk and float which happens as the batteries get close to being fully charged. You can have a fairly heavy draw on the batteries while in float as long as the solar is able to provide enough to match it; once the solar struggles to keep up, you’ll find it slips back into bulk again.

 

[Barry Chuckle]

Essentially float is when the batteries are full and it’s the necessary output from the controller to keep them topped off, bulk is when the batteries are depleted by pretty much anything and the controller is pumping in everything it can, while absorption is sort of a tapering between bulk and float which happens as the batteries get close to being fully charged. You can have a fairly heavy draw on the batteries while in float as long as the solar is able to provide enough to match it; once the solar struggles to keep up, you’ll find it slips back into bulk again.

Thank you ever so much for your detailed reply, that makes sense even to me!

 

[RockinNRollin]

Thank you ever so much for your detailed reply, that makes sense even to me!

I was in the same place when I first got my solar system; prior to that, in my mind batteries were either charged or not. The confusing bit (initially anyway) is the wattage readout on the Victron app is based on how much the MPPT is taking, not what's available. Absorption appears starts off with nearly 100% of available solar, but it gradually reduces as it gets nearer to float. This can be confusing if it's a sunny day and all of a sudden the panels are apparently only generating a quarter of what they're capable of, especially if there's little or no load on the leisure batteries (e.g. fridge is off).

 

[Peter84]

I've connected the negative to the chassis bolt but it doesn't make a difference.
I notice however that i.e. the Victron reports 12.7V and 1.00A on the battery while the control panel shows 12.6V and -3.00A (have the fridge running). Shouldn't they report the same number of amps?

Can't find anything obviously wrong with the cable to the panel, also cleaned the panel using a wet cloth, increased the power output slightly (to around 30 watts).

 

[Wannabecamperman]

I've connected the negative to the chassis bolt but it doesn't make a difference.
I notice however that i.e. the Victron reports 12.7V and 1.00A on the battery while the control panel shows 12.6V and -3.00A (have the fridge running). Shouldn't they report the same number of amps?

Can't find anything obviously wrong with the cable to the panel, also cleaned the panel using a wet cloth, increased the power output slightly (to around 30 watts).

Are you able to unclip the (I assume MP4) connectors and ensure no dust or grime between the connectors, then re-clip back together firmly? This and ensuring no roof bars or similar are shading ANY area of the panels is important for max wattage.

For example, I'm today (very sunny and warm) getting 176 watts from a 200w panel, which is typical.

 

[Peter84]

Don't think it's an MP4-connector. There is no obstruction at the moment, full sunshine on the panel and still only 20 watts.

I've booked it in with the installer. Thanks everyone for your help!

 

[Peter84]

It's a faulty solar panel indeed. Will be replaced under warranty.

 

[yossarian]

Thanks for reporting back: useful to someone in the future.

Victron reports 12.7V and 1.00A on the battery while the control panel shows 12.6V and -3.00A (have the fridge running). Shouldn't they report the same number of amps?

The victron reports the current flowing out of the mppt; the control panel reports the net current in or out of both batteries. These should be close to equal *if* there is nothing else in circuit that consuming power.