It can be daunting to figure out how long it will take to charge your LiFePO4 battery.
However, it’s pretty simple once you know how.
In this article, I will explain precisely how it works.
Let’s start off with a classic example of a 12V 100Ah LiFePO4 battery and a 10A battery charger.
100Ah / 10A charging current = 10 Hours
As simple as that!
Now you might ask, what if I have a 24V or 48V battery?
Good question!
Let’s use a 48V 100Ah server rack battery as an example with the same 10A charger.
100Ah/ 10A charging current = 10 hours
Did you see what happened there? Nothing changed!
Now, why is that?
If we calculate the charging power (watts), we can see that the power in the second example quadrupled because we have quadrupled the battery voltage.
Let’s calculate the charging power of these two batteries:
10A * 12V = 120W
10A * 48V = 480W
Always make sure you have the correct battery charger for your battery’s voltage.
Let’s reverse the calculations
Let’s say you are parked in a camping spot with your RV and need to recharge your battery overnight. Which Lithium charger do you need?
Let’s say your battery is 12V 280Ah, and you only have 10 hours to charge it.
280Ah / 10hours = 28Amps
To charge your 12V 280Ah battery, you need at least a 12V 28A battery charger.
In this case, I would use the 30A charger I recommended in my article about the best LiFePO4 chargers.
I guarantee this guide will save you $100s on buying the right components by having a good design and sizing.
You can get the book for a reasonable price on amazon
I’m an off-grid enthusiast. I created this website to give clear and straight-to-the-point advice about solar power. I’m also the author of the book ‘Off-grid solar power simplified‘. Read more about me on my about page, check out my Youtube channel, or send me a message.