Watts needed
I have read where folks suggest any where from 1 to 2 watts of solar per ah of battery. My question, is this based on battery rating (ie 215 AH) or is it based on useable amp hours(105)? All reply...
Forum Discussion
BFL13 wrote:I have the 250/100 ve can model, I also have the smart bluetooth shunt.https://www.victronenergy.com/upload/documents/Datasheet-SmartSolar-charge-controller-MPPT-250-70-up-to-250-100-VE.Can-EN.pdf
The solar controller usually has a display showing output amps and battery voltage. Some also have input info.
Is this one of those smart shunt, bluetooth deals? If from the shunt then that would be amps to the battery after any loads are taken care of, but I don't know how those work exactly. Might help to explain the set-up and a link to the Victron where you are getting the readings so we are talking the same language.
It takes about two minutes or so for the panels to heat right up when first put in the sun. Could your Pmax reading have been when they were first exposed to the sun?
I doubt that 99% efficiency for 24-12. Perhaps for 12-12 or 24-24. Are there efficiency curves for your controller? Ones I have seen show lower efficiency -mid 90s- the bigger the voltage diff between in and out for the buck converter in the controller.
Both the shunt and the controller transmit data to my phone. You may remember that I also have the factory Jaboni system. So the shunt shows what is being supplied by both systems, and the victron controller app shows what is happening with the Victron/AIMS 120 watt panels only.
When I got the 714 watt reading, the total of both systems read 923 watts, and it was negative 31-35 before enabling the solar. That means that the total solar system was putting out over 950 watts.... The total of both systems panels is 1020 watts. They are all flat mounted, It was around noon and I am in Phoenix AZ, so it was hot already before the panels were enabled... (I have a breaker box with breakers for both systems.
