question

mark1961 avatar image
mark1961 asked

Is MPPT 250/100 suitable for 8kw 48v pv array?

Hi everyone - first post so hope it’s not too stupid! I’ve just had a home solar system fitted 8 kw, 48 v feeding a 250/100 MPPT into 2 x Li-ion 4.8 kva batteries ( plus 5 kva inverter). The maximum power output I get ( midday, mid summer, high sun, clear sky, clean panels) seems to be c 5.5 - 5.7 kw when I would expect more like 7.5 kw - is this right?

MPPT Controllers
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
seb71 avatar image
seb71 answered ·

250/100 can output maximum 100A.

With a 48V (nominal) battery/system that means maximum of about 57.6Vx100A = 5760W. So exactly what you get.


When the sky is not clear, having more than 5760W in PV panels will help.

4 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

mark1961 avatar image mark1961 commented ·
Thanks. Does that mean that to take full advantage of what the array should output, which is 8kw that I have to add another MPPT or swap what I have for one with increased capacity -( if there is one? )
0 Likes 0 ·
seb71 avatar image seb71 mark1961 commented ·

Besides the RS 450/200 (which has 4 trackers), 100A is maximum charge current from Victron MPPTs.

If you want to produce more than 5760W, you would need a second MPPT and move some PV panels to that.

If buying a second MPPT makes sense depends on how many clear days you have during a year and if you can use all that power.

0 Likes 0 ·
mark1961 avatar image mark1961 seb71 commented ·
Thank you. I think I am right in understanding then, that even though I bought an 8 kw pv system that the MPPT that was installed (250/100) can’t cope with the full output of the array, and instead ( under optimum conditions) throttles it back to what it can cope with - 5.7kw rather than 8 kw.
0 Likes 0 ·
Show more comments