HI All,
I have 2 x 330w pannels with a 150/45 amp mmpt. Running a 460ah 12v bank
Everything seems to function fine until I use the bateries at night.
The controller does it thing, bulk, absorbtion then float. But of a night time the bateries drain about 50% faster than before I installed the solar system.
So when the solar system went to float and I was on shore power I turned the mains charger on and it went into a mode saying the bateries are only 3/4 charged...
Any ideas?
You dont have enough solar to charge up from 50%, unless you are producing more than 5 hours of the full panel rating.
230ah @ 12v is about 2.7 kWh. 660w of panels on would barely make that at the full 660w for 5 hours. Plus you have the batteries own inefficiency to overcome.
The mains charger would be aiming at bulk voltage target but your batteries are already at float voltage which is lower than bulk, so would start charging the batteries.
Are the settings the same on the mppt and the mains charger?
Thanks Alexander
I am aware of the capacity of the solar pannels vs batteries
Its just the mppt stops charging the batteries too soon. In the app it says at least. 2v lower than my installed volt meter.
I made the settings on the mppt so they are the same as the battery charger and once the solar had fully charged and over to float the sun went down. Still the bateries drained twice as fast. Therefore I did the same the next day an plugged in the mains charger to see if it registered the batteries as fully charged like the mppt did.. And it did not..
Hence tehe fact I am confused as to how to trouble shoot this..
If it has been undercharged for some time then you will possibly be running into issues like extra resistance in the batteries from sulphation.
Is 13.7v the set float voltage? It is also possible it is a tail current thing? Or a rebulk offset setting.
Have you verified the voltage at the terminals with a meter (not the voltmeter installed). And is there a disconnect or something somewhere as klim8skeptic suggests?. There may be a loose connection.
What is the mppt set to?
Better quality wire on the positive fixed it.. Knew it was not the Best wire but it was All that was around. So for now I just rewired with the same hight quality Black cable I had left over and everything matches up
Thanks for your advice
aption
