21-05-2025, 09:32 AM
We added a Solar charged UPS (8 panels + 2 , 6200 Wh, 2.5kW, 5kW peak, with controlled additional mains grid charging) then a secondary one with 2500Wh, 4 poorly sited panels and charges off main system if insufficient solar). Freezers can run indefinitely even December / January. Main power is more than 12 hours, or indefinitely if some stuff is shut down. All the socketed gear (via additional sockets) in four rooms, plus fridge, network gear/modem, satellite multiswitch and server in shed runs off it.
Note most smaller UPS use either 7 Ah or 14 Ah approx SLA/Gel batteries, that don't even have a cycle life quoted. When I worked in IT they were automatically replaced after a power cut or annually. The more expensive ones are 100 to 200 cycles if not discharged below 20% to 30% (depending on model). The current LiFePO4 cells used for solar are now a similar price as SLA per Wh and are 4000+ cycles down to 10% each time. That's more than 12 years.
The panels are now cheap (under €120), but you might get 1/20th of rated power in winter). Victron is best value/quality electronics. The Electronics is cheap if you don't supply to the National Grid. We only charge, so no certified installer needed.
If we had a smart meter we could limit any mains charging / topup to night and even in Dec/Jan save by shifting daytime consumption to grid at night.
Our previous PC UPS which was used for network, server and modem is now on server in shed simply to allow shut down of main solar ups . A trip switch and fusebox for stuff in the house doesn't feed the satellite multiswitch, workshop or server.
I had to fit a 12V antiphase transformer on the main solar ups/controller grid/mains in because not only is our 230V normally 245 to 250V, I saw it once at 262V. Waiting 7 weeks for Electric Grid operator to send someone. The system copes with brownouts or power cuts perfectly even if running off grid (it can use grid and solar to charge batteries at the same time if desired). It can't cope with over voltage. Somewhat above 250V it disconnects, shuts down and restarts on battery, rather than simply disconnecting (a Bluetti system, in retrospect all Victron would have been better. The smaller 1kW inverter and 2500Wh battery for freezers uses Victron. It uses a home-made solar panel -simulator in parallel with the four solar panels (connected as 2 x 2) to charge from AC (main grid or the main solar, currently the main solar). The simulator is a voltage doubler with 200W transformer, blocking rectifier on output (cold day, bright sun, fully charged means nearly 90V from panels) to protect electrolytics and a series 55W car head lamp bulb as a barretter (and additional fuse, though i/p and o/p of PSU is fused). Fascinating at night if battery needs charged to see the Victron MPPT "hunt" for best load point. You see the lamp via vent holes (it lives in a separate ex-PC PSU case) brighten and dim then go a steady bright orange.
I have also a 25 Ah 12V LiFePO4 as a portable power pack with a really cheap Victron MPPT and two small portable panels (100W max, typically 10W to 20W each) for portable use. It has 2x 12V to 2A USB-C adaptors and 3x pairs Anderson power poles all switch by Victron (disconnects if battery low) and one set power poles direct off battery for a 100W radio. All fits in a carry case with shoulder strap. The 12V 25 Ah is more like 13 to 14V normally and about 1/3rd weight of a same size SLA.
Note most smaller UPS use either 7 Ah or 14 Ah approx SLA/Gel batteries, that don't even have a cycle life quoted. When I worked in IT they were automatically replaced after a power cut or annually. The more expensive ones are 100 to 200 cycles if not discharged below 20% to 30% (depending on model). The current LiFePO4 cells used for solar are now a similar price as SLA per Wh and are 4000+ cycles down to 10% each time. That's more than 12 years.
The panels are now cheap (under €120), but you might get 1/20th of rated power in winter). Victron is best value/quality electronics. The Electronics is cheap if you don't supply to the National Grid. We only charge, so no certified installer needed.
If we had a smart meter we could limit any mains charging / topup to night and even in Dec/Jan save by shifting daytime consumption to grid at night.
Our previous PC UPS which was used for network, server and modem is now on server in shed simply to allow shut down of main solar ups . A trip switch and fusebox for stuff in the house doesn't feed the satellite multiswitch, workshop or server.
I had to fit a 12V antiphase transformer on the main solar ups/controller grid/mains in because not only is our 230V normally 245 to 250V, I saw it once at 262V. Waiting 7 weeks for Electric Grid operator to send someone. The system copes with brownouts or power cuts perfectly even if running off grid (it can use grid and solar to charge batteries at the same time if desired). It can't cope with over voltage. Somewhat above 250V it disconnects, shuts down and restarts on battery, rather than simply disconnecting (a Bluetti system, in retrospect all Victron would have been better. The smaller 1kW inverter and 2500Wh battery for freezers uses Victron. It uses a home-made solar panel -simulator in parallel with the four solar panels (connected as 2 x 2) to charge from AC (main grid or the main solar, currently the main solar). The simulator is a voltage doubler with 200W transformer, blocking rectifier on output (cold day, bright sun, fully charged means nearly 90V from panels) to protect electrolytics and a series 55W car head lamp bulb as a barretter (and additional fuse, though i/p and o/p of PSU is fused). Fascinating at night if battery needs charged to see the Victron MPPT "hunt" for best load point. You see the lamp via vent holes (it lives in a separate ex-PC PSU case) brighten and dim then go a steady bright orange.
I have also a 25 Ah 12V LiFePO4 as a portable power pack with a really cheap Victron MPPT and two small portable panels (100W max, typically 10W to 20W each) for portable use. It has 2x 12V to 2A USB-C adaptors and 3x pairs Anderson power poles all switch by Victron (disconnects if battery low) and one set power poles direct off battery for a 100W radio. All fits in a carry case with shoulder strap. The 12V 25 Ah is more like 13 to 14V normally and about 1/3rd weight of a same size SLA.
