MT50 and battery monitor question.

ShaggyGrower

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Joined
Sep 23, 2019
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19
Can someone explain why my MT50 shows much higher volts, amps and wattage being produced than my battery monitor is saying is going into the batteries?


IMG_20191001_122023.jpg
 

ShaggyGrower

New Member
Joined
Sep 23, 2019
Messages
19
Hi @Deno

Hope the above photos are clear. I have two battery monitors attached. One ("IN") gives me figures then there is more solar power being produced than used. The other ("OUT"") gives me figures when power is being taken from the batteries.

The wire colours going into each monitor go to the same terminals.

On the battery side, both grey wires go to the positive battery terminal.

On IN, the black wire goes to the battery side of the shunt on the negative terminal and the brown & blue wire both go on the other end of the shunt.

On OUT, brown & blue go on the battery side of the shunt on the negative terminal and the black wire both go on the other end of the shunt.

Did I put them in the wrong place?

Best regards, Shaggy
 

ShaggyGrower

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Sep 23, 2019
Messages
19
To the best of what I can see they all look correct. Is there anything load coming off the controller?

Thanks Craig. No load coming off the controller (ie, nothing connected the two load ports on the controller).

The diagram on the back of the battery monitor(s) had me confused. I did not know whether to put the batteries as they looked from the diagram at the back, or flip them the other way around, ie, the diagram showed what the connections should look like from the front.

I bought a second monitor so I could have the wires attached both ways to see what happened.

One thing I noticed is that where there is a load (via the inverter) on the system, if there is enough power being produced by the solar panels, the charge bypasses the battery monitor, ie, the battery "Out" numbers don't move, just the "In" ones are not reading higher.

I think the bottom right figure is total power In / Out, and the way I'm using them, hopefully correctly, is to try to make In equal or get close to Out, which I think tells me that the batteries are fully recharged.

There's always at least a small load, 1.1w measured on a 240v plug in adapter, due to the mechanical timer I have taking 1.1w.

I get the top left figure, volts, but the other two figures top right and bottom left, Current and Power respectively, have me a bit confused as to what they mean and how they're calculated. I'll put a picture in the next post showing the figures on the MT50 and the two battery monitors.

Best, Shaggy
 

ShaggyGrower

New Member
Joined
Sep 23, 2019
Messages
19
So, the above photo was taken near the end of the day, so not much is being produced by the solar panels.

There is a load going through the inverter at this time.

The MT50 tells me a some charge is being produced.
"In" I think tells me there is no charging going on due to Current and Power being zero.
"Out" I think tells me that the batteries are discharging.

I think the solar power that is being produced goes straight to the inverter and then a bit more from the batteries is as well, enough to power the demand from the load on the inverter.

What I don't understand is the Current and Power figures.

I think the load on the inverter (led light) was ~40w. Volts on the inline plug in monitor (not pictured) tells me this, with a voltage of ~232v.

Not sure how the Current and Power figures are calculated and relate to the plug-in monitor figures, and this is the bit I'd like to understand now.

Best, Shaggy
 
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