Measuring Solar Panel output

[mark1882]

Hi
I have 2 Victron 80w solar panels wired in series going to a Victron MPPT controller.
I would like to be able to monitor the output from the panels. I have read about how to do this with a multi meter but what I am looking for is some form of gauge I can have permanently wired in so I can check the output without having to use a multi meter.
I appreciate that the output to the batteries will be controlled by the MPPT controller dependant upon the state of charge of the batteries, so what I am looking for is being able to manage the output prior to the batteries ie the output before the controller decides how much to put in the batteries.

Any advice as to what sort of quauge I could use would be appreciated and whether this should be wired in before the controller or inbetween the controller and the batteries.

Thanks
Mark

 

[mark1882]

I meant measure the output not manage the output, bloody spell checker !!!!!!

 

[VicS]

Really not sure what you want to do, or why.

You say you have read how to do this with a multimeter. But what parameter is the multimeter measuring.

I cannot see that measuring volts out from the panel will be meaningful.

Perhaps you are thinking of measuring current if so a little panel ammeter in series with the solar panel will do it, but I am not sure what use the information will be. The reading will depend on how much is being fed by the controller to the battery

Perhaps an ammeter monitoring the charge current to the battery will be of some interest ????


I think it would be better to forget it, hoist the sails and go sailing!

 

[William_H]

Yes actual current from the controller to the batteries is what would be most interesting.
Ebay will give lots of amp meters some with volt meter as well all digital which are ideal.
On the other hand a moving coil amp meter with a shunt can fit ina panel requires no power to operate it and will continually read out charge current.
This kind of thing oz dollar is about 40 p. But available in UK.
Here is an ebay page of digital amp meters with volt meter.
http://www.ebay.com/sch/i.html?_fro...t+meter.TRS0&_nkw=volt+amp+meter&_sacat=92074
good luck olewill
http://www.altronics.com.au/search/all/?sr=Amp+meter

 

[macd]

Wot the other said.

Additionally, since you seem to like Victron, Mark, how about one of these (assuming it's compatible with your particular controller)?: http://www.victronenergy.com/panel-systems-remote-monitoring/mppt-control

Alternatively, a battery monitor would give you a reasonable idea of (regulated) panel output. A battery monitor capable of accepting multiple shunts would give you a perfect idea if a shunt were fitted into the controller output.

P.S. Sorry. Noelex's post #7 has alerted me that I'd misunderstood the OP's question, inasmuch as he wants to know the power the panels are generating pre-controller. For the reasons stated by Noelex, I can't see that this is particularly useful. If the OP's desire is to be able to check for any fault in the panels, surely this would quickly become obvious from measurement of the regulated supply?

 

[charles_reed]

Really not sure what you want to do, or why.

You say you have read how to do this with a multimeter. But what parameter is the multimeter measuring.

I cannot see that measuring volts out from the panel will be meaningful.

Perhaps you are thinking of measuring current if so a little panel ammeter in series with the solar panel will do it, but I am not sure what use the information will be. The reading will depend on how much is being fed by the controller to the battery

Perhaps an ammeter monitoring the charge current to the battery will be of some interest ????


I think it would be better to forget it, hoist the sails and go sailing!

My BZ 500 has a 3 position switched meter, giving battery volts and PV amps in and MPPT controller amps out.
I have to say I find it invaluable for checking state of charge and the best angle for the panels.
It's difficult to know what you don't know, isn't it.

 

[noelex]

I appreciate that the output to the batteries will be controlled by the MPPT controller dependant upon the state of charge of the batteries, so what I am looking for is being able to manage the output prior to the batteries ie the output before the controller decides how much to put in the batteries.

Solar regulators work by (very quickly) turning the solar panel off and on. So both the input and output current are reduced when the regulator is limiting the current to the batteries.

Measuring the current at the output side is usually more useful.

Measuring the input current does not help determine the potential output of the solar panels without regulation. The only way to do this with a normal solar regulator is to to turn on a high load to force the regulator to drop out of regulation and deliver the maximum current to the batteries.

 

[peteK]

Surely a Watt meter is what you need plenty on eBay for less than £10.

 

[oldvarnish]

You need one of these. I have one and it tells you everything you need apart from a bedtime story:

http://www.blueskyenergyinc.com/products/details/sun_charge_30

volts in/ out, amps in/ out, and AH of charge

 

[jakeroyd]

I use a clamp type multimeter bought I think from Maplin.
in current mode you surround one wire with the jaws and read amps directly.
it can not read amps in a twin core or more cable.
FWIW in bright sunlight I read about 1.6a from a 30w semi flexible panel directly out of the panel , I've before any regulator.

 

[Chris_Robb]

Mark, I have the older type STECO controller. I was surprised at your request for your Victron as the STECO shows amps generated at regulated voltage from the sun panels and by pressing another button, the amps going into the battery. The NASA BM1 shows obviously the net in and out usage at any point in time. A small amp meter using a shunt would work - you want one in the range 1 to 20 amps.

In doing a search on Victron MPPT's this came up
http://www.ebay.co.uk/itm/Victron-E...06f109&pid=100338&rk=4&rkt=30&sd=301718319853

It has a bluetooth connection to a smart phone whose app can see exactly what you want - I dont know if you have the same base unit? Have a look