How many days of reserve, and what that costs.
Autonomy days and critical loads
Decide which loads must survive, then how many days — most systems are sized for two days of critical load.
- How 36V LiFePO4 Batteries Handle High Current Loads
- What Is Battery Reserve Capacity and Why Does It Matter
Recharge window and generator backup
Check the array or generator can refill the bank between events, or autonomy is theoretical.
- How to Choose an Elite LiFePO4 Rechargeable 60V 200Ah Battery for OEM Needs
- How Do 24V Lithium Battery Chargers Work Safely
- Which Chargers Work For 12V, 24V, 36V, 48V Lithium
- Comparing Self-Discharge Rates: 12V LiFePO4 Batteries vs. Other Battery Types
- What Impact Do Discharge Rates Have on 24V LiFePO4 Performance
- What is the Typical Discharge Curve for 36V LiFePO4 Batteries
- Optimal Voltage Levels for a Fully Charged 12V Battery: An In-Depth Guide
- Can You Overcharge a 12V Lithium Battery
- What Voltage Indicates a Fully Discharged 48V Battery
- How Can You Tell When Your 12V Lithium Battery Is Fully Charged
Voltage & sizing questions
Short answers to the ones that come up most.
How do I choose a battery voltage?
It is set by the equipment: 12V small loads, 24V light traction, 48V storage and most traction.
How do I work out runtime?
Amp-hours times nominal voltage for watt-hours, divided by the real load, minus 10–15% losses.
Why is a 12V lithium battery 12.8V?
Four 3.2V LFP cells in series; 12V equipment accepts the range.
What does C-rate mean?
Current relative to capacity — 1C on 100Ah is 100A.
Can I series-connect different batteries?
No — same model, capacity and age, or the strings unbalance.