Tātaitai battery bank
Tātaitia te kaha battery bank me te autonomy mō tētahi uta.
Whakamātau mahi 6
Ka whakakī ia mahi i ngā uara tauira. Whakakapia ērā ki ō uara.
- Size a battery bankThe bank capacity the loads need for the autonomy days.
- Size a 12 V battery for a camperThe Ah for a fridge and lights for one day.
- Size a 24 V PLC panel backupThe Ah to hold a 120 W panel for four hours.
- Size a bank for three winter daysThe Ah for three days of autonomy.
- Size a lithium bankThe Ah at 90 % depth of discharge.
- Size a bank for a cold siteThe Ah with a cold-temperature factor.
Ngā whakauru
He tauira mahi me ngā whakauru taunoa.
- Ngā utanga
- 2 rārangi
- Whakahiato pūnaha
- 48 V
- Hōhonutanga whakaputanga
- 0.5
- Pai o te inverter
- 0.9
- Tauwehe pāmahana
- 1
- Wā mana motuhake
- 1 days
Kaha hiahiatia
225.93Ah
- Pūngao i ia rā
- 4,880Wh
- Utu ia rā
- 112.96Ah
He āwhina hoahoa tēnei hua. Manatokohia ki te paerewa o nāianei.
Ngā hīkoi tātaitanga
- Hiko ia rā4,880Wh
- Utu ia rā112.96Ah
- Kaha e hiahiatia anaHua225.93Ah
Mō tēnei tātaitai
How this is calculated
The tool sizes a battery bank in ampere-hours for a set of loads. It reads no table, so it cites no clause.
- Inputs. You enter each load in watts with its hours of use. You also enter the system voltage and the depth of discharge. Then you enter the inverter efficiency, the temperature factor and the days of autonomy.
- Energy per day. For each load, it multiplies the power by the hours of use. It adds the loads.
- Charge per day. It divides the daily energy by the system voltage and by the inverter efficiency. The result is the daily charge in ampere-hours.
- Required capacity. It multiplies the daily charge by the days of autonomy and the temperature factor. It then divides by the depth of discharge.
The depth of discharge is the share of the battery you allow to be used. A lower value gives a larger bank. The temperature factor is 1 at normal temperature. A value above 1 adds capacity for a cold site.
Worked example
- A 48 V bank for two loads. The loads are 500 W for 4 h and 120 W for 24 h. The depth of discharge is 0.5 and the inverter efficiency is 0.9. The energy per day is 4,880 Wh. The charge per day is 112.96 Ah. The required capacity is 225.93 Ah.
Limits
The tool gives capacity only. It does not choose a battery chemistry, a charger or a cable. For the cable between the bank and the inverter, use the DC cable size calculator.
The result assumes the loads are the same each day. It does not model charging from solar or the grid. It does not model battery ageing or a changing discharge rate. For a home battery with an inverter and solar, use the home battery tool.
The tool uses one system voltage for the whole bank. A 24 V bank and a 48 V bank hold the same energy but give different amp-hours. Take the depth of discharge from the battery maker. It differs between chemistries.
See also: Battery bank for three days of autonomy, Off-grid battery bank at 48 V and Home batteries and AS/NZS 5139.
Pātai
He āwhina hoahoa te hua. Manatokohia ki te paerewa o nāianei.
He aha te mahi a te tātaitai pākahiko?
Ka tāpiri te taputapu i te hiko o ia uta ka uruhia e koe, i ngā wāti me ngā hāora. Ka huri i taua hiko ia rā ki ngā ampere hours i te voltage pūnaha. Kātahi ka pūrongo i te kaha pākahiko e hiahiatia ana mō ngā rā autonomy ka tonoa e koe.
Ko ēhea ngā uruhanga e tino nui ana?
Ko te rārangi uta me ngā rā autonomy e ine tika ana i te kaha. Ka wehea e te depth of discharge, ko te taunoa 0.5. Ko te efficiency o te inverter, ko te taunoa 0.9. Ka whakareatia e te temperature factor te putanga, ko te taunoa 1. Ko te voltage pūnaha e whakatau ana i ngā ampere hours.
He aha ngā mea kāore e mahia e tēnei taputapu?
Kāore e rahi i ngā taura, i te charge controller, i te puna whakawiti rānei. Kāore he tūtohi paerewa e tohua ana, nō te mea he tātaitanga tōtika te putanga. Whakamahia te taputapu Rahi Taura mō te ara DC. Ka noho ngā uruhanga ki te wāhitau o te whārangi, nō reira ka whakaputa tētahi hononga i te rahinga.
Ngā tauira mahi
- Arc flash at a 48 V home batteryClass a 48 V lithium home battery with 6 kA at its terminals by AS/NZS 5139, find its arc flash energy and PPE level, then bring it down with fuses.
- Battery backup for a PLC panel at 24 V DCSizing a 24 V DC backup bank for an 80 W PLC panel over one day of autonomy, with the daily energy, the daily charge and the bank capacity the tool returns.
- Where can a home battery go? Garage wallsA garage wall that backs onto a bedroom, with a hot water cylinder nearby. See which AS/NZS 5139 location rules fail for a home battery, then fix each one.
- Solar battery size for a family home: 25 kWh a daySize a solar battery for a home that uses 25 kWh a day with an 8 kW array. Usable and nominal kWh, the bank, the inverter, winter solar and where it can go.
- Off-grid battery bank autonomy at 48 VA bach load list of 7600 Wh per day at 48 V needs 703.7 Ah of battery for two days of autonomy at 0.5 depth of discharge, worked step by step.
- DC cable size: 48 V battery and 600 V PV arrayTwo d.c. circuits sized to AS/NZS 3008.1.1:2025, a 48 V battery-to-inverter run that current sizes and a 600 V array feed that voltage drop sizes.
Kōrero o muri
- Home batteries and AS/NZS 5139How a home solar battery is sized in kWh, what usable, nominal, depth of discharge and round-trip efficiency mean, and where AS/NZS 5139 lets one go.
- Control panels and PLC wiringSegregation of LV and ELV in a control panel, terminal and numbering practice, panel earthing, and the 24 V DC voltage drop that long instrument loops fail on.
- PV and inverter basicsHow a grid-connected PV system connects to an installation, why voltage rise sets the inverter cable, and which standards the AmpSize tools cannot quote.
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