Sent email to Steca, Germany as follows
Dear Sir/ Madam
On Thurs 6th November I bought, from Wind and Sun - one of your registered distributors, a Pro1010 controller, serial number 953154, to regulate the output of two 50 watt solar cells to a 100Ah battery.
I connected them yesterday around 2pm 8th November and noticed the draw on the battery, according to the inbuilt monitor, was 0.1A. As there was no load connected I thought the 0.1A which occasionally flashed to 0.2A was the units inability to process the low self consumption, rated in your manual as 0.0125A (12.5mA).
I was going to disconnect the unit from the battery overnight in case there was such a usage but decided to leave the battery connected.
This morning around 8am I checked the usage and found the total at 2Ah. As I have write this email at 10am it reads 3Ah. This, I reiterate, is with no load connected to the output terminals.
So at 10am
Solar in 2.4A
to Battery 1.2A
The above figures are a mystery
I assume the 1.2A is being dumped to heat whilst the 'load' seems to rise with Solar input; yet is still 0.1A at night. Could you please explain these readings as they are not what I would expect nor want?
Looking forward to your response.
P.S. I served in the Royal Navy as a Radio Electrician so I am familiar with a little more than basic electrical wiring.
Fri 7th I connected one panel, via the Steca Controller, to one old battery. Used it as load battery and measure a use of 10Ah total.
Could see from the Steca the Asus 900 uses 1 amp
Sat 8th Since then I have 2 old 50w panels connected via the Steca to one old battery. The other old battery I have topped up with water, which was a bit iffy as it was a sealed battery. The six cells needed about a litre so hardly surprising it/they were almost unrechargeable.
That battery as end of day on the 9th was rated as 52% charged, by the next morning is was 48%
I arose at 4am on the morning of 10th Nov to read the Load Ah and the Steca records 5Ah. It is now nearly 10am and the reading is 6Ah. I suppose I can relay on the fact that the phantom use it consistent. Some 6Ah in 44hour (6000mA divided by 44 = 136mA) some 11 times the specified 'own consumption' of 12.5mA.
It begs the question; What is it measuring?
Clearly it is not measuring the load as I would expect.
Why would it measure it's own consumption?
What happens to the waste power when the current is too much for the battery state? Is it measuring that?
It seems that although it is interesting, having some monitor, these questions make it a inaccurate in terms of power measurement.
I assume the Ah into the battery actually pass through the battery terminals. I say this as the Charge Ah is the same as the Load Ah, although I noticed during charging yesterday they did not keep pace and the Load Ah only caught up over night. I wonder if I disconnect the battery from the Steca will it still show the Load Ah, but then obviously not as it will have no power, but I could try it in the day.???
So is this reading an un-understandable one or is it me that is failing to understand how the Steca works?
If you think this unit is faulty please send me another and I will install it and return the current one if that is the case. Of course as you didn't sell me the unit directly maybe you could authorise Wind and Sun to send me one.
I wonder if you actually test the unit as I do? i.e. without any load for a significant time and if you do could you please sent me your data. Better still could you please send me the data anyway
All the best