27-11-2022, 08:48 PM
Sort of Mike,
A decent stand alone solar system starts at 48 volts of batteries, but I have built 240 volt battery systems.
Conversion efficiency for 240 volts DC in and 240 volts AC out runs almost at 100% so its worth the extra effort.
Remember too, that shifting 240 volts from the paddock to the battery shed is much cheaper than shifting 48 volts.
We use 4mm ^2 solar cable. I wouldnt like to pay for 6mm or 8mm cable !!.
In the bush here, a large cattle station has its own butchery and it quite often kills a bullock or two.
A small system like 48 volts hasnt got the oommppphhh to run a freezer system for two days to chill the resulting meat.
You have to go higher. Its sad but true, the higher your battery voltage the lower your current, so a 1000 Ah battery can supply 240 volts
for quite some time. Remember too that here we can have long periods of very hot sunshine, so pumping up a big battery bank is fairly easy.
We always fit diesel generators though too, as its not uncommon in the wet season to have two weeks of rain and no sunshine.
We dont have summer or winter, just wet and dry seasons. The temperature doesnt vary much from the standard old 35 or 36 degrees every day.
Back to the origional question: MOST of those little UPS systems are pretty cheap junk, but decent ones are available.
They will be made in china too, but you get what you pay for.
Joe
A decent stand alone solar system starts at 48 volts of batteries, but I have built 240 volt battery systems.
Conversion efficiency for 240 volts DC in and 240 volts AC out runs almost at 100% so its worth the extra effort.
Remember too, that shifting 240 volts from the paddock to the battery shed is much cheaper than shifting 48 volts.
We use 4mm ^2 solar cable. I wouldnt like to pay for 6mm or 8mm cable !!.
In the bush here, a large cattle station has its own butchery and it quite often kills a bullock or two.
A small system like 48 volts hasnt got the oommppphhh to run a freezer system for two days to chill the resulting meat.
You have to go higher. Its sad but true, the higher your battery voltage the lower your current, so a 1000 Ah battery can supply 240 volts
for quite some time. Remember too that here we can have long periods of very hot sunshine, so pumping up a big battery bank is fairly easy.
We always fit diesel generators though too, as its not uncommon in the wet season to have two weeks of rain and no sunshine.
We dont have summer or winter, just wet and dry seasons. The temperature doesnt vary much from the standard old 35 or 36 degrees every day.
Back to the origional question: MOST of those little UPS systems are pretty cheap junk, but decent ones are available.
They will be made in china too, but you get what you pay for.
Joe
