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EVE 280Ah - 6 months later

upnorthandpersonal

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So after running my 32 EVE cells for the past 6 months I decided to pull my weakest cell and do a capacity test. Tester used was a CBA IV, at 20A discharge (can not really do a .2C test right now). Result:

280Ah_EVE_dis.png

Ignore the bump at the 50Ah mark, I tightened the nuts better around that time - but this doesn't make a difference for the capacity test (see this video).

So my weakest cell after 6 months of pretty heavy use (do not know the exact cycle count) comes in at 274Ah. I can probably still squeeze another Ah or two extra out of it.
 
Just curious:
Are you running start Series Packs or do you have paralleled cells ?
Did you Top Balance or Bottom to Top balance prior to installation ?
The above noted Cell, is it a "Runner" ? or a Lazy ? You say "weakest" so I am assuming the Lazy one in the gang.
 
No paralleled cells: just two times 16s packs in parallel, with both packs having individual BMS (i.e., every cell is monitored).
I did a top balance before assembling the packs. The 'weakest' cell is the lazy/runner one in the bunch; it tends to get both highest and lowest first.
 
So after running my 32 EVE cells for the past 6 months I decided to pull my weakest cell and do a capacity test. Tester used was a CBA IV, at 20A discharge (can not really do a .2C test right now). Result:

Ignore the bump at the 50Ah mark, I tightened the nuts better around that time - but this doesn't make a difference for the capacity test (see this video).

So my weakest cell after 6 months of pretty heavy use (do not know the exact cycle count) comes in at 274Ah. I can probably still squeeze another Ah or two extra out of it.
That is reassuring info to have presented. (y)
 
So my weakest cell after 6 months of pretty heavy use (do not know the exact cycle count) comes in at 274Ah. I can probably still squeeze another Ah or two extra out of it.
Do you know what the capacity of that cell was when you received it?
 
I love when people take the time to revisit their purchases / experiences over time!

All these capacity tests people do are great, but when it comes to proving the claims regarding # of cycles, that's an entirely different challenge all together!

I mean, if you're paying xy% more for a battery expecting 3x cycles, then it's important to know if you're getting your $$$ worth!
 
Hi, please what is your current experience with your eve cells, its almost a year now, are they still pulling a decent capacity? Also can you estimate like how many circles you may have done? Thanks in advance for your response
 
No paralleled cells: just two times 16s packs in parallel, with both packs having individual BMS (i.e., every cell is monitored).
I did a top balance before assembling the packs. The 'weakest' cell is the lazy/runner one in the bunch; it tends to get both highest and lowest first.
I'm planning a 48v system, would you mind sharing any pics and also the BMS part numbers you have been using for this?

THX!
 
Hi, please what is your current experience with your eve cells, its almost a year now, are they still pulling a decent capacity? Also can you estimate like how many circles you may have done? Thanks in advance for your response

Well, it's only about 3 months since I posted this graph, so not much changes since then. I really don't know how many cycles I did since I did not monitor this in detail - it's not very easy to do since you usually don't do full cycles at all. The cells still hold up fine and I expect them to do so for many years to come. When I add another 32 this year, it'll probably be even longer...
 
I'm planning a 48v system, would you mind sharing any pics and also the BMS part numbers you have been using for this?

THX!

It's on the forum here in several threads, here:


A picture of the cells with my flexible bus bars is all the way at the end of that thread.

The BMS is a Heltec (JK) BMS. There are several threads on this one on this forum as well.
 
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