Author Topic: LiFePo4 battery spec?  (Read 178 times)

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Offline Superscan811

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LiFePo4 battery spec?
« on: September 09, 2020, 02:46:07 am »
Purchased then pulled apart a 100AH Li Fe Po4 battery in order to find out what cells they are using.
Can't find any information on this cell from the numbers on the tags
There are 28 batteries (4 banks of 7 cells)  which would make them around 15ah.
Any one know or have any idea what the true specs might be?

Cheers.


Offline WooferHound

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Re: LiFePo4 battery spec?
« Reply #1 on: September 09, 2020, 04:32:50 am »
What battery did they come from.
There is a Guy on YouTube that does battery Tear Downs and he may have done that battery already.
Here is an example of one of his battery disassemblys . . .

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Offline rossw

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Re: LiFePo4 battery spec?
« Reply #2 on: September 09, 2020, 05:13:36 am »
Purchased then pulled apart a 100AH Li Fe Po4 battery in order to find out what cells they are using.

There are 28 batteries (4 banks of 7 cells)  which would make them around 15ah.

Point of order!

You have one "battery", consisting of 28 "cells".
It's litterally a "battery of cells".

Offline WooferHound

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Re: LiFePo4 battery spec?
« Reply #3 on: September 09, 2020, 05:17:03 am »
Measure the Cells
The cells are named for their size
I use 18650 cells in my Solar Power , pronounced "Eighteen Six Fifty".
Named 18650 because they are 18mm in diameter and 65mm long , <<edited to correct mistake<<
Some other common sizes for Lithium batteries are . . .
20700
21700
26650
28650
32650
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Offline WooferHound

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Offline Pete

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Re: LiFePo4 battery spec?
« Reply #5 on: September 09, 2020, 06:06:12 pm »
Hi Woofer, the conversion measurements you gave seem strange.
You said that an 18650 cell measured 18mm round and 650mm long.
That is a very long cell, 650mm in your measurements is just over 2 foot long.
Maybe the 650 means 65mm.
Pete

Offline WooferHound

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Re: LiFePo4 battery spec?
« Reply #6 on: September 09, 2020, 06:17:17 pm »
Maybe the 650 means 65mm.
Pete

Haaaa . . . You are so correct , and I thought I knew what I was talking about. Shows how much I use the Metric System ?
There was a battery I found that was bigger than 42120 that had the correct amphours.
Just a quick measuring will make it easy to find.

Doesn't really matter anyway.
If you are going to make a battery, just get enough of whatever cell you can get a good price on.
If you can find new lithium batteries cheaper than a $1 an amphour then jump on it.
Start here . . .
https://batteryhookup.com/
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Offline Superscan811

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Re: LiFePo4 battery spec?
« Reply #7 on: September 09, 2020, 08:49:07 pm »
I'll measure the battery size this afternoon but I'd say they are close to the 42120...
Just working out the $ per KWH.
$400 for a 100amp hour 12.8v = $312.50 per KWH.
Not too bad for new cells here in Australia.