ok so continuing on from my introduction post as I think this is the proper place to expand on what I want to do and learn from you more experienced guys at the same time.
Ok just to quickly go over what I already have.
I have a 6 kw and a 4 kw solar edge system ofsolar Pannels. 6 of the panels are on a solar tracker I built my self and it was well worth it for the 30 to 40% extra power generated from them.
I have also just bought a victron mult 5kw with 5 kWh of byd b boxbattery storage. The idea was to use this as a base battery system and then build my own batteries with the eventual aim of having 30 kWh plus of storage.
I'll try to post some pics or at least links to pics later to show what I've done.
Right. The battery storage I have so far consists of 2 2.5 kWh byd batteries. These have their own bmu or bms for controlling the charge etc. I have them set up so that each battery has its own main cable back to the victron multi. The multi does all the charging by converting ac to dc. It also inverts the dc back to ac when battery power is required.
Mybatteries reached fully charged for the first time today at a voltage of 56.4 volts. I believe the spec on the byd battery means it can produce power to quite a low voltage and the bmu does not switch off the discharge until 47 volts I think from memory but I'll double check this.
So from what I'm told an 18650 is fully charged at 4.2 volts and fully discharged at 3.4 volts. But I have also read that fully charging to 4.2 and fully discharging to 3.4 is bad for the battery and will shorten its life.
Knowing that batteries will self ballence from the highest cell to the lowest I was thinking I could use the byd batteries bmu to monitor the two byd batteries between their charged 56.4 volts and empty 47 volts then rig in my home built batteries. The bmu controlled b box batteries should automatically keep my own built batteries in check as the current should just flow between them from highest to lowest.
Now I know that the b box batteries are fully charged at 56.4 volts so if I build 14 packs of lion cells when the byd batteries are fully charged each of my own cells should be charged to 4.02 volts and when the byd batts are discharged to 47 volts my lion cells would be at :.357 volts which is a little low so I'm pretty sure in the set up of the victron the upper and lower voltage drain and charge cutoffs are configurable so I could raise the cut off drain voltage to 47.6 volts which would stop the std lion cells from being discharged too far.
What do u think guys.
Ok just to quickly go over what I already have.
I have a 6 kw and a 4 kw solar edge system ofsolar Pannels. 6 of the panels are on a solar tracker I built my self and it was well worth it for the 30 to 40% extra power generated from them.
I have also just bought a victron mult 5kw with 5 kWh of byd b boxbattery storage. The idea was to use this as a base battery system and then build my own batteries with the eventual aim of having 30 kWh plus of storage.
I'll try to post some pics or at least links to pics later to show what I've done.
Right. The battery storage I have so far consists of 2 2.5 kWh byd batteries. These have their own bmu or bms for controlling the charge etc. I have them set up so that each battery has its own main cable back to the victron multi. The multi does all the charging by converting ac to dc. It also inverts the dc back to ac when battery power is required.
Mybatteries reached fully charged for the first time today at a voltage of 56.4 volts. I believe the spec on the byd battery means it can produce power to quite a low voltage and the bmu does not switch off the discharge until 47 volts I think from memory but I'll double check this.
So from what I'm told an 18650 is fully charged at 4.2 volts and fully discharged at 3.4 volts. But I have also read that fully charging to 4.2 and fully discharging to 3.4 is bad for the battery and will shorten its life.
Knowing that batteries will self ballence from the highest cell to the lowest I was thinking I could use the byd batteries bmu to monitor the two byd batteries between their charged 56.4 volts and empty 47 volts then rig in my home built batteries. The bmu controlled b box batteries should automatically keep my own built batteries in check as the current should just flow between them from highest to lowest.
Now I know that the b box batteries are fully charged at 56.4 volts so if I build 14 packs of lion cells when the byd batteries are fully charged each of my own cells should be charged to 4.02 volts and when the byd batts are discharged to 47 volts my lion cells would be at :.357 volts which is a little low so I'm pretty sure in the set up of the victron the upper and lower voltage drain and charge cutoffs are configurable so I could raise the cut off drain voltage to 47.6 volts which would stop the std lion cells from being discharged too far.
What do u think guys.