Hi, I have previously posted questions about my battery instal and received good advice, thanks for that. I though I would post a more detailed run through of my installation that may be of interest.
I had been thinking about battery storage for a while and eventually, after much research and head scratching, decided to plunge completley into the DIY route! Initially my thinking was an AC inverter and expandable battery racks so I could start small and add units as and when. Pylontech looked a good option. However then found that Seplos cabinet kits were available that you assembled and put in the EVE cells. I managed to obtain a lightly used Victron Multiplus 2 5000KVA inverter and found someone local to me who imports the kits and cells direct from China.
Before going too far down the road I started my G99 application for a total possible export capacity of 8kW. I already had a Solaredge 3.6kW PV system installed a year ago and wanted that to remain as is. Filled application forms and sent diagram, map showing connection point to the grid and had quite a few back and forth emails as my diagrams did not show G99 protection for inverter, even though this is done in the inverter and was labelled accordingly. This was all done from a campsite in France on holiday. Eventually had to call them to clarify exactly what they wanted and they required the diagram to also show the G98 protection for the already installed PV inverter. Eventually the information was acceptable and the decision would take a few months
In the meantime I picked up my kit / cells from and began the journey. The Seplos cabinet was well packaged and a lot of it had been already assembled. I had read that the components were loose in plastic bags inside the cabinet but they now have all the items in cardboard boxes.
The Inverter control unit and display from Victron was around £500 but the Venus OS can be installed on a Raspberry Pi and performs the same functions for around £200. This was duly built.
The detached concrete garage walls and roof had had 50mm insulation and overboard with plywood a few years ago. A space was cleared and fireproof cement board installed and the Inverter was stuck up on the wall.
Began the wiring and replaced the 4 way consumer unit with a 6 way and ran an additional CAT 6 cable from the meter cupboard under the stairs for the CT clamp. This entailed an additional metal conduit to be installed between the house and garage.
While the wiring was being done I stuck the cells in parallel and top balanced them using a Riden power supply. This took ages, but gave me plenty of time to do the wiring at my own pace.
BMS was pretty much pre assembled just had to be connected up. As someone else had mentioned about the Seplos kit, the plastic cover for the fuse holder had to be cut to accommodate the connectors.
Due to the weight of the cabinet and cells I assembled the kit in situ so as not to have to move the battery too far. Even though it is on castors it is still a heavy beast.
I have fitted two heat pads (for aquariums) to the wall behind the battery controlled by an STC1000 . (Thanks to johnb2713 for this idea and other advice). I have this set to heat when temperature falls below 10° but think that the heat from the inverter will keep this corner of the garage around that temperature. The winter will tell.
Got an offer of acceptance from SP for the full 8kW export capacity and got a local electrician in to double check the AC wiring and connect to the consumer unit. I had bought a second hand Multifunction Tester on eBay and had done Insulation resistance, continuity and Zs tests anyway. But good to have a second pair of eyes look over it.
Big switch on came and there were no loud bangs and apart from an incorrect setting for the CT clamp it all seemed to work.
It has been running now for about three weeks and thankfully it appears to be working well. Due to reducing solar I schedule charging during the Octopus Intelligent 23:30 - 05:30 slot. There have been a few days where solar has charged it up and I haven't needed to do this.
Will have to play about with settings to get it working efficiently. On the advice of the chap who supplied the kit and batteries, who has built a fair few of these, I have not used the CanBus data connection from battery to inverter. Instead it uses the Victrons' voltage sense. It is set to show 100% charge when it reaches 55.2v absorption voltage. I have to research this further but it seems to be working ok and the displayed Victron SOC tracks the BMS SOC. I may at some stage connect up the CamBus but not sure what advantage this may give apart from seeing the battery data from within the Venus OS. Adding a shunt may also be an option for more accurate data. However, as I said it appears to be happy without this at the moment.
I have the battery SOC displayed on my Home Assistant dashboard and the next stage is to integrate it more fully with HA.
Commissioning documents have been sent to SP, still waiting for a reply but fingers crossed they are happy.
Cost of the 15kW kit was £2400, Inverter £1200 and all the other bits and pieces brought the total cost to £5000. This included about £500 - £700 for the MFT, power supply, battery resistance meter etc some of which will be used for other things. In fact the MFT helped me find that the garage ring circuit live conductor was broken.
I have a background in Electrical and Electronic Engineering (mainly the electronic side) and it has been a huge learning experience and now that it's pretty much done (apart from tinkering) I can concentrate on our kitchen renovation! I would say that anyone thinking about going down the DIY route should give it a go, however, be prepared for it to take a while, and there is a lot of work and research required. But its pretty satisfying and keeps the old brain working!
I had been thinking about battery storage for a while and eventually, after much research and head scratching, decided to plunge completley into the DIY route! Initially my thinking was an AC inverter and expandable battery racks so I could start small and add units as and when. Pylontech looked a good option. However then found that Seplos cabinet kits were available that you assembled and put in the EVE cells. I managed to obtain a lightly used Victron Multiplus 2 5000KVA inverter and found someone local to me who imports the kits and cells direct from China.
Before going too far down the road I started my G99 application for a total possible export capacity of 8kW. I already had a Solaredge 3.6kW PV system installed a year ago and wanted that to remain as is. Filled application forms and sent diagram, map showing connection point to the grid and had quite a few back and forth emails as my diagrams did not show G99 protection for inverter, even though this is done in the inverter and was labelled accordingly. This was all done from a campsite in France on holiday. Eventually had to call them to clarify exactly what they wanted and they required the diagram to also show the G98 protection for the already installed PV inverter. Eventually the information was acceptable and the decision would take a few months
In the meantime I picked up my kit / cells from and began the journey. The Seplos cabinet was well packaged and a lot of it had been already assembled. I had read that the components were loose in plastic bags inside the cabinet but they now have all the items in cardboard boxes.
The Inverter control unit and display from Victron was around £500 but the Venus OS can be installed on a Raspberry Pi and performs the same functions for around £200. This was duly built.
The detached concrete garage walls and roof had had 50mm insulation and overboard with plywood a few years ago. A space was cleared and fireproof cement board installed and the Inverter was stuck up on the wall.
Began the wiring and replaced the 4 way consumer unit with a 6 way and ran an additional CAT 6 cable from the meter cupboard under the stairs for the CT clamp. This entailed an additional metal conduit to be installed between the house and garage.
While the wiring was being done I stuck the cells in parallel and top balanced them using a Riden power supply. This took ages, but gave me plenty of time to do the wiring at my own pace.
BMS was pretty much pre assembled just had to be connected up. As someone else had mentioned about the Seplos kit, the plastic cover for the fuse holder had to be cut to accommodate the connectors.
Due to the weight of the cabinet and cells I assembled the kit in situ so as not to have to move the battery too far. Even though it is on castors it is still a heavy beast.
I have fitted two heat pads (for aquariums) to the wall behind the battery controlled by an STC1000 . (Thanks to johnb2713 for this idea and other advice). I have this set to heat when temperature falls below 10° but think that the heat from the inverter will keep this corner of the garage around that temperature. The winter will tell.
Got an offer of acceptance from SP for the full 8kW export capacity and got a local electrician in to double check the AC wiring and connect to the consumer unit. I had bought a second hand Multifunction Tester on eBay and had done Insulation resistance, continuity and Zs tests anyway. But good to have a second pair of eyes look over it.
Big switch on came and there were no loud bangs and apart from an incorrect setting for the CT clamp it all seemed to work.
It has been running now for about three weeks and thankfully it appears to be working well. Due to reducing solar I schedule charging during the Octopus Intelligent 23:30 - 05:30 slot. There have been a few days where solar has charged it up and I haven't needed to do this.
Will have to play about with settings to get it working efficiently. On the advice of the chap who supplied the kit and batteries, who has built a fair few of these, I have not used the CanBus data connection from battery to inverter. Instead it uses the Victrons' voltage sense. It is set to show 100% charge when it reaches 55.2v absorption voltage. I have to research this further but it seems to be working ok and the displayed Victron SOC tracks the BMS SOC. I may at some stage connect up the CamBus but not sure what advantage this may give apart from seeing the battery data from within the Venus OS. Adding a shunt may also be an option for more accurate data. However, as I said it appears to be happy without this at the moment.
I have the battery SOC displayed on my Home Assistant dashboard and the next stage is to integrate it more fully with HA.
Commissioning documents have been sent to SP, still waiting for a reply but fingers crossed they are happy.
Cost of the 15kW kit was £2400, Inverter £1200 and all the other bits and pieces brought the total cost to £5000. This included about £500 - £700 for the MFT, power supply, battery resistance meter etc some of which will be used for other things. In fact the MFT helped me find that the garage ring circuit live conductor was broken.
I have a background in Electrical and Electronic Engineering (mainly the electronic side) and it has been a huge learning experience and now that it's pretty much done (apart from tinkering) I can concentrate on our kitchen renovation! I would say that anyone thinking about going down the DIY route should give it a go, however, be prepared for it to take a while, and there is a lot of work and research required. But its pretty satisfying and keeps the old brain working!
