I recently bought a house that was owned by an electrician and he has some interesting stuff set up that I have been trying to learn about. The previous owner unfortunately died and nobody knows anything about all the stuff he set up, but I've been having fun learning about it. First he has a 4kw grid tied solar rig on the roof, which is nice as it's part of an old renewable scheme so I get paid something to generate electricity even if I use it. That's all professionally done and self explanatory.
The other main thing I found was a very interesting off grid wind setup. He has a huge pole with what looks like a 500w to 1kw domestic wind turbine on it. It runs down into a cabinet that has a cheap 12v wind controller connected to two 12v 72AH lead acid batteries in parallel.
He also had this interesting thing where a light detector switched on grid charging at night and then he ran DC lights off it, but I am ripping all that out as I just want to use whatever I can get out of the wind for free.
So I've started learning about how these systems work, and I bought what is probably a very oversized inverter to run AC off the batteries. I am in the UK so we are 240v, and I got a 2500w (5000w peak) 50hz pure sine inverter. I wired it to the batteries using 16 mm cables, and it works but I have some issues/questions:
1) The batteries seem to float around 12.4v to 12.7v (measured by inverter) and when the wind is blowing they get up to 13v+. Is this low, and is this an indication that the batteries are old and dying? Or is that normal for a charged 12v battery?
2) The voltage drops when there is load on the inverter, dropping a whole volt when under about 250w load. I'm guessing this is normal as we are drawing charge from the battery?
3) I tried putting 1000w+ load on the batteries just to see if it could handle it, and I got a low voltage cut out at the inverter after a second. Voltage dropped to 10.5ish before it cut out. Am I right in assuming I would basically need a much bigger battery bank and thicker cables to be able to draw that large a load without dropping voltage into the red?
4) It's clear that I bought a much too large inverter. Is that going to be a problem? If I am only putting 250 to 500w load on this system, would a lower rated inverter actually be more efficient or is it not a problem?
Looking forward to any advice and answers anyone can give me. I've been reading up a lot on this since moving in. My goal is to add a bunch more battery capacity and more solar panels to the system. My sheds are all wired up with lighting and extension leads (to run power tools) that come from the house via an external socket, and I'd love to be run them off the batteries instead.
The other main thing I found was a very interesting off grid wind setup. He has a huge pole with what looks like a 500w to 1kw domestic wind turbine on it. It runs down into a cabinet that has a cheap 12v wind controller connected to two 12v 72AH lead acid batteries in parallel.
He also had this interesting thing where a light detector switched on grid charging at night and then he ran DC lights off it, but I am ripping all that out as I just want to use whatever I can get out of the wind for free.
So I've started learning about how these systems work, and I bought what is probably a very oversized inverter to run AC off the batteries. I am in the UK so we are 240v, and I got a 2500w (5000w peak) 50hz pure sine inverter. I wired it to the batteries using 16 mm cables, and it works but I have some issues/questions:
1) The batteries seem to float around 12.4v to 12.7v (measured by inverter) and when the wind is blowing they get up to 13v+. Is this low, and is this an indication that the batteries are old and dying? Or is that normal for a charged 12v battery?
2) The voltage drops when there is load on the inverter, dropping a whole volt when under about 250w load. I'm guessing this is normal as we are drawing charge from the battery?
3) I tried putting 1000w+ load on the batteries just to see if it could handle it, and I got a low voltage cut out at the inverter after a second. Voltage dropped to 10.5ish before it cut out. Am I right in assuming I would basically need a much bigger battery bank and thicker cables to be able to draw that large a load without dropping voltage into the red?
4) It's clear that I bought a much too large inverter. Is that going to be a problem? If I am only putting 250 to 500w load on this system, would a lower rated inverter actually be more efficient or is it not a problem?
Looking forward to any advice and answers anyone can give me. I've been reading up a lot on this since moving in. My goal is to add a bunch more battery capacity and more solar panels to the system. My sheds are all wired up with lighting and extension leads (to run power tools) that come from the house via an external socket, and I'd love to be run them off the batteries instead.