upgrade from 12v to 24v system

[ason]

Hi I have a Epever tracer 4215BN and a 270Wp panel,
Here is the spec.

Maximum Power (Pmax)		270 Wp
Voltage at Maximum Power (Vmpp)		30.5 V
Current at Maximum Power (Impp)		8.85 A
Open Circuit Voltage (Voc)		38.21 V
Short Circuit Current (Isc)		9.21 A
Panel Efficiency		16.51 %
Power Tolerance (Positive)		2%

And now I think to get one more panel, what i have read is that i need an panel that is equal the one I have already,
Equal in what parameters, Vmpp, impp or al of them?
so what do I need to thinking of?

Is this a good one to use together with the one i already have?

https://www.projectsolaruk.com/wp-content/themes/betterenergy/pdf/Evo-Max.pdf

[sensij]

When you put panels in parallel, you want the Vmp's to be close. When you put panels in series, the Imp's need to be close.

Your charge controller will be fine with adding a panel either in series or in parallel to what you have. If you add in parallel, the voltage stays the same and the current is doubled, so you'd see higher losses on the run from the panels to the charge controller. Adding in series is probably the better option if you will be able to mount the panels so they have the same orientation and are getting the same amount of sunlight.

The Evo-max panel you suggested has a Vmp of 31.78 and an Imp of 8.97. The current matches your existing panel better than voltage does, but both match within 5% and would be considered compatible. Putting it in series looks like the right choice, but again, that assumes they will mounted with the same azimuth and tilt, and will more or less see the same shading.

[ason]

Now I have a 12v system 2x240Ah batteries, and wanna use 24v in the future.
When I bought the batteries, I got a charger 24VDC/45A that am going to use from a generator in case of emergency
Parallel, will it be the lowest voltage that i have to my system?
And series lowest amps?
How big a difference works without breaking things?

[sensij]

Yes, you will need to put the second panel in series with the first to support a 24 V battery.

[ason]

Yes, you will need to put the second panel in series with the first to support a 24 V battery.

I know that, but wonder about this:
Parallel, will it be the lowest voltage that i have to my system?
And series lowest amps?
How big difference voltage/amps works without breaking things?