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cool video Alex, thanks for sharing. it's surprising that it doesn't lose any load over night, for some reason would have expected a small percent change.
 

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cool video Alex, thanks for sharing. it's surprising that it doesn't lose any load over night, for some reason would have expected a small percent change.
Me really the same. I actually expected that it will loose at least 1%, or maybe 2%. I was really surprised, that it was the same state of charge after 24 hours.

It's because they saying, as more the battery is loaded, as more fast it's loosing load.
And if it's almost empty, it's almost not loosing load anymore.


I really like that kind of surprises.. :D:D:D
 

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I ordered 46 x LFP 200 Ah cells when I built my EV but only could fit 45 cells into my enclosure . The spare cell measured 3.217 volt (from factory) with my Fluke multimeter December 2017 (summer) , a few weeks ago I checked it July 2018 , its still 3.215 volt . (winter) I have never charged it & who knows low long it was sitting in storage before delivery.

I have been told if you are going on long holidays don't fully charge your EV, the cells maintain their SOC at their nominal voltage (3.2 for LFP ) easily for 6-12 months , so long as there is no parasitic loads . This is where BMS vampire boards are not good.
 

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Lithium batteries do not self discharge. They do lose some capacity as they age which can look like a small loss unless you account for it. If you disconnect everything from a cell and store it at half charge it will be essentially unchanged when you look at it 10 years later. Capacity will be reduced by approximately 2.5%.

Of course if you have a BMS board which powers itself from the cell it is connected to you will see some loss due to powering the BMS. And since each board presents a slightly different load on each cell you also see an imbalance in the pack.

There is no mechanism in a lithium ion type cell that could cause a self discharge.

Hope that helps.
 
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