The journey starts.
I'm looking at a 48v system, as many of the inverts are sitting in this range, in addition the current draw is less (less loss to heat) for the same wattage compared to low voltages. For commercial system, the DC voltage is much higher for efficiency, however at 100v up it gets dangerous....at 50v you will feel it. I am basing this voltage on 14S52P (14 modules in series, with each module of 52 batteries in parallel) which will give me around 12kwh. 14S rather than 13S seems to be where members are leaning as the preferred build. It is expected for a 12wkh system to have 80% usable power (battery longevity) , so in actual real terms should have ~10kwh true available power. I have decided to go with 5000mah as they are the most cost effect for the price point for new batteries.
I have been buying:
New 186505000mahfrom DHGate ~$1.74AUD a cell.
Batteryholder Module - 13*4 52 holes for 48v 10ah li-ion battery pack from Aliexpress ~$10 a set of 2....would like to get them cheaper.
Need to get:
Copper flat bar 15mm x 3mm x 250mm;battery side bus bar. (130AMP (6Kw peak current at 48v * 130A)per module based on AWG ~ 50 degrees C)
Smaller copper rod bus bar for top of batteries...not sure on the size?
0/2 AWG Lugs and associated hookup wire.
Heat Shrink tubing to colour code bus barends.
0.5 mm tinned copper fuse wire (~35AMP burnout)
Inverter Charger or Hybrid Solar Inverter (5kw), as I have 5kw of solar.
Gas Soldering torch to solder copper bar. A soldering iron will not handle the heat loss of the bars.
14SBattery Management System (BMS)
Need to consider:
Over Temperature (fire) isolation.
Eliminate easily combustible materials around battery pack construction.
Reduce risk of module shorting. Lithium batteries have a very low internal resistance and will happily dump their load in a very short period of time; melting/fusing and generally self destructing.
With luck nailed in 12 months
I'm looking at a 48v system, as many of the inverts are sitting in this range, in addition the current draw is less (less loss to heat) for the same wattage compared to low voltages. For commercial system, the DC voltage is much higher for efficiency, however at 100v up it gets dangerous....at 50v you will feel it. I am basing this voltage on 14S52P (14 modules in series, with each module of 52 batteries in parallel) which will give me around 12kwh. 14S rather than 13S seems to be where members are leaning as the preferred build. It is expected for a 12wkh system to have 80% usable power (battery longevity) , so in actual real terms should have ~10kwh true available power. I have decided to go with 5000mah as they are the most cost effect for the price point for new batteries.
I have been buying:
New 186505000mahfrom DHGate ~$1.74AUD a cell.
Batteryholder Module - 13*4 52 holes for 48v 10ah li-ion battery pack from Aliexpress ~$10 a set of 2....would like to get them cheaper.
Need to get:
Copper flat bar 15mm x 3mm x 250mm;battery side bus bar. (130AMP (6Kw peak current at 48v * 130A)per module based on AWG ~ 50 degrees C)
Smaller copper rod bus bar for top of batteries...not sure on the size?
0/2 AWG Lugs and associated hookup wire.
Heat Shrink tubing to colour code bus barends.
0.5 mm tinned copper fuse wire (~35AMP burnout)
Inverter Charger or Hybrid Solar Inverter (5kw), as I have 5kw of solar.
Gas Soldering torch to solder copper bar. A soldering iron will not handle the heat loss of the bars.
14SBattery Management System (BMS)
Need to consider:
Over Temperature (fire) isolation.
Eliminate easily combustible materials around battery pack construction.
Reduce risk of module shorting. Lithium batteries have a very low internal resistance and will happily dump their load in a very short period of time; melting/fusing and generally self destructing.
With luck nailed in 12 months