GWL/Power Group - EV & Power Solutions
You can see a lot of their products at: http://www.yttrium-power.com
Disclaimer: I have no affiliation with the company, but they have treated me in a swift and very professional manner.
They did require payment before delivery, which tends to turn on all my alarm bells.... I did quite a bit of research on them (aka googling), and they did seem genuine enough - so I went for it.
They have responded quickly to my (sometimes) stupid questions ;-)
I did recieve a discount for promoting them, so make up your own mind, but I will, and can, recommend them.
|The 68 LFP90AHA still unpacked||Apparently some transport damage.|
One damaged cell. The clear liquid is visible on the side of the cell.
According to the friendly people at GWL/Power Group the liquid is:
"...an anti-oxydizing liquid to protect the cell against degradation caused by the reaction with air (or Oxygen). The cell will continue working, but it will not last 20 years. In may get oxidized internally after some time depending on the environment. If the cell is "closed again" the cell will work fine".
|Another picures of the same cell.|
|Crack at the positive terminal.||Crack in the side by the negative terminal.|
|Same crack as on the previous picture but from another angle.||Part number of the damaged cell.|
|The neighboring cell that perhaps did the damage.||The cells below the damaged cell.|
|The cells below the damaged cell.||One of the wood boxes - no visible damage to the cells.|
|All 67 non-damaged cells ready for initial charge/discharge/charge cycle.||List of the part numbers.
The cells are made up by three different part number series. Two from 14'th October 2009 (091014) and one from the 26'th og February 2010 (100226).
|The test setup. The power supplies (only using one) are located to the left. The load on the right. And the Agilent data logger is on the top shelf.||The power supply.|
|The load (up to 3kW).||A cell attached to the charger.|
|Another cell attached to the load.||List of the Initial Open Cell Voltage (OCV), Initial Charge, First full discharge and charge cycle.
The list is work in progres and will be update when the data is ready.
The next step will be 2 steps more or less... I will pair up the cells I have measured and connect them in series.
This should give me a battery of 16V/194Ah and I will test this battery with a 0.3C (60Amp) constant current discharge/charge cycle.
From this I hope to gain two things:
The bulk charge will be 30Amp into 10 cells until the first cell reach 4.0V.
The discharge will then be done witn 30Amp until the first cell reach 2.8V and the doing the rest individually.