What does depth of discharge mean?
The depth of discharge of a battery represents the percentage of the battery that has been discharged relative to the total battery capacity.
How to Calculate Depth of Discharge and State of Charge
For example, if you have a 100Ah battery and you're only using 20Ah, your battery is 20% discharged, which means your depth of discharge is 20% and your state of charge is 80%. If you take the same 100 amp hour battery and discharge it to 70%, your DOD will be 70% and your SOC will be 30%. It is important to understand the DOD calculation because depending on your battery, the number of cycles will vary depending on your DOD.
Lithium battery cycle life and depth of discharge
The cycle life of most lead-acid batteries is significantly reduced if the discharge is below 50% DOD. LiFePO4 batteries can be continuously discharged to 100% DOD with no long-term effects. However, we recommend that you only discharge to 80% to maintain battery life.
Lithium battery capacity and discharge rate
Another great advantage of LiFePO4 batteries is that the discharge rate has little effect on the delivery capacity. This is not the case with lead-acid batteries, which can significantly reduce their capacity by as much as 50% as discharge rates increase. Lithium batteries provide 100% of their rated capacity regardless of discharge rate, while lead-acid batteries typically provide less usable energy at higher discharge rates. What does this mean to you? Ultimately, you can get more hours of power with a lithium battery.
If you still have any questions about deep cycle lithium batteries, please contact our team of lithium battery experts so we can help you get on the right track.