Advice on stand alone P.V. system upgrade please ...

Hello All ,
By stand alone I mean off grid -domestic
I have a few questions about where to go now with this situation -I have an existing System that doesn't have quite enough juice so i will be enlarging the existing capacity. so I have bought some kit which I can't take back so therefore will need to use .

Existing system

2 x 40wp kyocera panels

15 amp 12/12vdc controller (Leo 1)

6 x 2vdc (12v total) 200 ah batteries (hoppoeke)

and a 1000w cheap modified sine wave inverter .

The upgrade idea .

Change to 24 v

fit x 5 100wp panels (isc 6.39 , uoc 21.6 , vp 17.2 ,ip 5.82 ) already bought

studer c2600 inverter charger (already bought)

I need a regulator also with room for more panels at a later date

double the storage capacity.


I really wanted to know what sort of regulator to buy - mppt with the extra cost ? and If to go for a Brand name again at extra cost or go for one of the many cheap versions ?

I was looking at 60a MPPTs by Morningstar , Outback and Xantrex.

please let me know what you think .

Many thanks

It depends what your primary mover is AC or DC

If AC get an inverter for the new panels, if DC, why not just get the MorningStar TriStar TS45 or TS60 and charge the batteries directly (put it in Solar Battery Charging Mode) it's not an MPP tracker, it's just a charge controller.

We're rigging one up for a customer with 4 x 250W Moser Bayer panels (he already had them) to 4 x 6V Rolls batteries and we reckon we'll cut down his generator usage phenominally, the uprade won't be more panels, it'll be more batteries for night time useage. Only problem with that set up is that it doesn't qualify for the off-grid 19p/kWh, however his install costs have been negligible (I'll post a photo tomorrow and you'll see how!)

Thanks for getting back to me. I'm interested in seeing the installation you mentioned .PWM s are alot cheaper but do i lose out much in the long run ? I also didnt realise there was a different tarrif for off grid either ( I wont qualify as my place is in spain anyway)

Another question will my two panels (80wp) keep the larger bank of batteries charged (2400Ah) , x 12 x 2 v batts in parallel, as i may be pushed for time actually there .

Beacuse it doesn't need MCS approval etc, there are lots of things you can do that you couldn't if MCS was required...

Here's the mounting system (faces dues south) not yeat finsihed - cables need tidying up (securing, rain drips etc) this phot taken tonight at 8:15pm so sun set already.



Need to know the Voc of the panels and the actually arrangement of the batteries beofre I could comment, remeber once they are fully charged, that's it, then the controller usually just open circuits the panels.

Looks I wrote my last my past post and didnt post it .
Is the pictured job for a back up system ? Is it with a generator ? If so seems similar to mine / what i want to do.
If your still here -my spec amps are about 2.36 and VoC is about 20 ish i think , havent got the spec to hand (its in spain).the panels are in parallel and batteries will be set up as 6 x 2 v in series and then this in parallel to keep it 12v .Do you have a dc disconnect for the the panel , the regulator and the batteries and for both sides of the of the inverter ?

Cheers