# LFP batteries Ampere-hour comparison

#### mudell

Hi all,

I’m new here and I would like to ask a question for my better understanding of Ampere-hour ratings of LFP batteries. Would be great if someone would spare some time to help out !

Assuming I have 2 batteries each having 10kWh capacity:

Battery 1: 10kWh, 48V, 208.33Ah (low voltage)

Battery 2: 10kWh, 450V, 22.22Ah (high voltage)

My question is- does this mean that battery 1 will last around 9x longer than battery 2, due to the higher Ah rating of battery 1?

Thanks for helping !

#### ron simpson

If your load was a 1kw light bulb each battery will last 10 hours. (more or less) The two batteries have the same ability to hold power.

If you load was 20 amps, then Battery-1 will last 10hours and Battery-2 will last about 1 hour. (20a x 28V is very different than 20a x 450V in watts) The answer you are looking depends on what the load is.

Take 10 batteries. (48V 22A each) If you series the batteries (stack them up) you will have 480V at 22A. OR If you parallel the batteries they will have 48V at 220A. This like having 10 buckets of water. No matter how you rearrange the buckets you have 10 buckets.

#### mudell

Hi Ron thanks for the reply.
Why is it that if the load is a 1kw bulb, each of the batteries I mentioned will last around 10 hrs but if the load is 20A, they will last differently ?
In my question i am assuming the exact same load for both batteries.

Thanks alot once again

#### ron simpson

i am assuming the exact same load for both batteries.
1kw load at 450 volts is 2.2 amps.
1kw load at 48 volts is 20.8 amps.

First we must define what LOAD is. It could be 1kw. Or it could be 2.2A or 20.8A.
I normally think watts because that is a measurement of work or energy.
Amps is volume. Electron flow has no energy in it unless there is voltage to push the flow.
If you pulled 20 amps from the 450 volt battery, that is 9,000 watts! not 1kw.

#### mudell

Now it is more clear. Thanks Ron !

#### simon mugo

Hi all,

I’m new here and I would like to ask a question for my better understanding of Ampere-hour ratings of LFP batteries. Would be great if someone would spare some time to help out !

Assuming I have 2 batteries each having 10kWh capacity:

Battery 1: 10kWh, 48V, 208.33Ah (low voltage)

Battery 2: 10kWh, 450V, 22.22Ah (high voltage)

My question is- does this mean that battery 1 will last around 9x longer than battery 2, due to the higher Ah rating of battery 1?

Thanks for helping!
the two batteries' performances will depend on the amount of current you drain on each of them. If the current you are draining is the same, then battery one will lust at least 9 more hours than battery two ie when you use a constant current load.
the A-h is the most important characteristic in batteries and it is the one that determines how the battery efficiency will be during discharge.

#### Keonte45

No. It all depends on the load and in turn, the amount of current drained by each battery.