Hi.
I'm wondering how many amp mppt controller need to received from panel to start charging battery?
As I noticed, most of times mppt need from panel need more then 2.2A to start charging.
As you see on screenshot below ones even 2.41A and 28 W to battery wasn't enough to start charging, (battery is on idle not charging).
Or i think wrong and this is normal?
It is not the Amperes but the Voltage.
The MPPT need a Voltage which is 5V higher thrn the Battery voltage.
Since you have a 12V system, i assume, that your panel is 18V. This minght give in the UK a serious problem
I suggest you to install a second Solarpanel of the exact same type in series to increase the Voltage or use a singel 32-38V module.
The 5V offset is correct, but I am confused by the provided screenshot as well. According to the screenshot the MPPT delivers 37W at 2.41A and runs in bulk charging mode. The AC system is switched off. The battery is discharged with 28W at 2.1A. (I assume that positive numbers at the battery imply that the battery is discharged, not charged.) This means there is a total of 65W of power and 4.51A of current which "magically" leaks out of the system.
Does the screenshot fall short of showing DC loads?
I'm in a similar situation with the same weather. But the screen shot does show the battery is charging, just not quickly. As said above, more panels needed for this weather. But in a month or two, there will be little or no solar.
Your Victron mppt controller watch model 75/15 or 100/20 ? and is the panel on camper roof ? i.e. flat if so you may wont consider ground mounted panels so you can change panel angel in to sun all year round as an add on to your system you will need to add second solar control in parallel battery side as power point will be different add on panels
if your setup fix roof mount i.e. shed
ever way from your vrm mppt dater you need more PV volts as sun moves south in the sky day by day your solar power will get low
