Ampster
Renewable Energy Hobbyist
They did use Amphours which to their advantage did not take into account the declining voltage during discharge of FLA.
New 280K cells not pulling full capacity
- Thread starter dimsi
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sunshine_eggo
Happy Breffast!
This was my experience. 9 cells, 263-279. Met IR and self-discharge specs. Failed to meet capacity.
IMHO, this is normal.
Very few of @cinergi 's cells made capacity...
diysolarforum.com
IMHO, this is normal.
Very few of @cinergi 's cells made capacity...
36 EVE 280 cells capacity tested
I just completed testing 36 EVE 280AH cells purchased in the Group Buy thread. Tester: https://www.aliexpress.com/item/32821857011.html Wire gauge increased to 10. Connected to cell via lugs (in other words - a high quality connection, not the alligator clip method). Amperage: 15 Temperature...
diysolarforum.com
Alkaline
Solar Wizard
Yes I have learned this, Amp hours only is not a good way even on my Luyuan Cells I got less AH than 280 but I did get 899 WH so in reality it is meeting capacity.
Also I just realized the fan tester had was set to 2.5V cut-off but I checked the cell it self and it said 2.68V so may be 1-2 AH was left ?
timselectric
If I can do it, you can do it.
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Voltage will bounce back up, after load is removed. (Rested Voltage)
Alkaline
Solar Wizard
the tester kept saying less than 2.5v but the terminals were 2.68 I think some voltage is dropping from the wires. Maybe set the tester to 2.4v?
timselectric
If I can do it, you can do it.
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Scarry
For the 5C test I used the JBD bms's metrics for tracking ah capacity and a Kisae pure sine wave inverter running resistance loads. For the 0.1C test I used the capacity tester you get from amazon, the ones that go up to 185w. I spent some time calibrating the voltage and current on the tester, but I noticed, like others, the voltage is not accurate in the low numbers.
Alkaline
Solar Wizard
no way to upgrade the wires on the zke they are 10 awg. on my fan tester I'm using 10 awg also and 24 guage for the v-sense. Results nearly the same always between 278-280 and betwen 899-902 WH.
I'm having to rerun the test on basen 280DK cells because stupid windows decided to do an update and ruin my test after a restart
The one thing we don't count on is the actual manufacturing process of the cells themselves.
The original cell manufacturer, not the distributor, as part of the initial forming and commissioning process, may actually take the cells up beyond the standard 3.65v, say to 3.8 or 4.0v *JUST ONCE* and squeeze out say 10% more capacity.
They may be basing their AH ratings on that initial higher-voltage forming process, which we don't want to do in normal every day use. In fact, DO NOT do this at home.
The original cell manufacturer, not the distributor, as part of the initial forming and commissioning process, may actually take the cells up beyond the standard 3.65v, say to 3.8 or 4.0v *JUST ONCE* and squeeze out say 10% more capacity.
They may be basing their AH ratings on that initial higher-voltage forming process, which we don't want to do in normal every day use. In fact, DO NOT do this at home.
Last edited:
sunshine_eggo
Happy Breffast!
Many cell data sheets include the discharge test parameters, and they do not include exceeding 3.65V.
Check 3.5 through 3.7:
Need new avatar - it always makes me hungry.
Part of the reason for not including that may be due to early DIY EV history.
Taking cells up to say 4.0v *only once* is part of the commissioning process for Winstons - even today. Other brands used 3.8v.
Problem is, many early users mistook that for being an ok CV in daily use, which as we know is not good!
So to avoid those end-user diy-gaffs, that first one-and-only-once commissioning voltage done at the factory is never revealed. Too many returns with plated cells.
Part of the reason for not including that may be due to early DIY EV history.
Taking cells up to say 4.0v *only once* is part of the commissioning process for Winstons - even today. Other brands used 3.8v.
Problem is, many early users mistook that for being an ok CV in daily use, which as we know is not good!
So to avoid those end-user diy-gaffs, that first one-and-only-once commissioning voltage done at the factory is never revealed. Too many returns with plated cells.
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