280 battery choices

[Maitake]

I am in the process of choosing a vendor for a 3p16s battery made from EVE280 batteries. I have been all over the map from the cheapest us stock $110 each to new cells with data sheets from Amy Wan at $165 delivered from China.

I am currently leaning towards the new cells.
Here is why.
1) I can order 48 which is the number I need, instead of padding my order to account for possible bad cells.
2) if the battery has a 10 year life, every year is a 10% loss in value. Some of the grey market cells getting delivered are 2 years old already.
3) fool around time. Project is large and complex enough already without chasing down runner/bad cells or hassling with vendors over quality.
4) quick math on the above and the difference to buy new spec sheet eve cells over the alternative is like $100-$200/year over the pack lifetime.

I have never been sad to buy quality, and have regretted cheaping out many times over the years.

Any input is welcome.

 

[Steve_S]

I have everything from Used "real ev" cells to Bulk & B Grade as well as the "properly" Matched & Batched A Cells.
Zero Issues with teh Matched cells they hum along as happy as can be and do not diverge much at either end of the Gross Voltage Curve.

I Bulk/Absorb Charge to 3.500Vpc for 45 Minutes (EndAmps set to 14A) then FLOAT at 3.475Vpc from there on. I have a Large Bank of 5 packs.
When entering float, deviation for the "Matched Pack" is on average 35 millivolts, During float the cells balance down to 10v difference (my settings). When float terminates the cells are at 3.400 +/- 10mv (it is a running live system).

Bulk Cells can be as much as 100mv difference at the start of Float. The worst pack (1st batch of Bulk) can actually get pushed to 250mv diff between cells. A Good Active Balancer does help knock that down and level it out fairly well... I have been using QNBBM-8S (I'm 24V) Active Balancers and they do work well BUT are not programmable or monitorable. I am now in process of switching all my battery packs to JKBMS with 2A Active Balancing built-in which can be programmed & actively monitored.

In summary, you DO get what you pay for. Amy Wan's prices reflect this and is NOT out of line. If you bought 100 Cells and then had them independently Matched & Tested, it would cost up to 50% of the cost of the cells, including the failures to meet spec. BY her using the Matched & Batched cells done (tested) by EVE (she purchases directly and does not use Brokers) you are getting the "real deal".

DO NOTE, that FEW offer Genuine Matched & Batched cells, some are now making "clone spreadsheets" to make them appear as properly tested. BUT if you look at "Direct from Manufacturer" Matched Cells from ANYONE, they will cost 25%+ More pending on volume, IF you can get them... Remember that a LOT of focus is towards EV's with LFP as well as Big Commercial Energy Storage Systems companies who are all transitioning to LFP Chemistry.

Hope it helps, Good Luck.