# CALB and Sinopoly 40/60/100Ah test results



## rwaudio (May 22, 2008)

This is a continuation of my thread CALB CA / A123 / Sinopoly testing, what would you like to see? but instead of burying the results a few pages in I thought I'd start a new one.

I have completed the first round of testing on the 40 and 60 Ah cells. Ambient temperature is a pretty consistent 22.5C (low could be 20 with a high of 25).

Lets start with the 40's

Physical dimensions and weight, are virtually the same.

Cells are hooked up as if I was installing them in my car, terminals cleaned, rings/nord locks, braided straps etc.










Both cells were discharged CC-CV at 40A to 2.5v and let sit for 1 hour or longer to stabilize.

In the following graphs the Sinopoly 40 is cell 1 and the CALB 40 is cell 2:
Charging:
























Still charging Sinopoly only as it was not full yet:
















Discharging:
















Sinopoly only, continued discharge:

















I'm not going to play battery expert here, just post my results.
There is a slight mismatch in charge/discharge capacity as you see on the graphs, there are actually 2 more sets of graphs as I lowered the charge current not believing that the CALB was already full, I got another 0.5-0.75Ah into both cells that isn't shown, I'll send them to you if you want but they don't show anything useful.
The CALB is difficult to describe, capacity is crap, but the discharge curve itself and IR look normal.
Regardless of what the CALB does or doesn't do, on it's own the results of the Sinopoly are actually quite impressive for a 40Ah cell at 1C discharge.

Later I will be testing the 40's in the car at up to 400A for short periods.


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## rwaudio (May 22, 2008)

The same testing methods went into testing the 60's, however as I learned from the 40Ah test, after the calb was full/empty I charged/discharged the Sinopoly on it's own so the capacities will add up based on the graphs shown.

Again for the 60's Sinopoly is cell 1 and CALB is cell 2.

Charging: (the PL6 drops the current in an attempt to completely charge the pack after the first cell hits CV at high current, this is at around 1.5 hours that's why the charging graph is so long)
























I would only put value on the first 1.5 hours of the IR measurement as after that the current dropped from 40A to 0.5A

Charging the Sinopoly the rest of the way by itself.
















Discharge:
















Discharge, finishing the Sinopoly on it's own:

















The results appear "normal" I've tested a lot of CALB 60's and I would consider this cell to be "average" or just a bit below average as far as capacity. If all Sinopoly 60's come in at 65Ah with a 1C discharge I have to say I'm impressed. The rest of the curves look pretty normal as well.

I believe the in car test results of the 60's will provide a good indication of how these two brands stack up in the real world.


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## rwaudio (May 22, 2008)

Again the same testing method for the 100Ah cells.

One notable difference on the Sinopoly is the significantly larger terminal contact area even though they both use M8 bolts.










100Ah Sinopoly is cell 1 and 100Ah CALB is cell 2

Charging:
























As you can see the Sinopoly didn't terminate charge, I charged it on it's own but it only took an extra 0.3Ah over the CALB, I'm happy to provide the graphs but I don't believe it's worth posting.
Discharging:

















Capacity and discharge curves are virtually identical. The results are promising, however the open circuit voltage of the cells after sitting for 12-24 hours is much higher for the Sinopoly cells which suggests a higher state of charge, in my cell testing experience this would signify a cell with higher internal impedance.

Based on this I would suspect that at high currents the Sinopoly cells will have more voltage sag than the CALB cells.


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## EVfun (Mar 14, 2010)

I want to thank you for doing these tests and publishing the results. I'm looking forward to some higher current results.  The big flat center area on both of the 60 amp hour cells looks a lot like what I see with my Thunder Sky LiFeYPO4 cells. They have about 1.5 milliohms internal resistance in the real world (5C stays above 2.8 volts until low on charge.)


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## rwaudio (May 22, 2008)

To wrap up the bench testing I ran a pair of A123 batteries through the same process. They are set up as a 2S4P pack made from 20Ah A123 gray market cells.
I had previously tested this group at 77Ah as it produced here. The cell groups are very close so the entire charge/discharge cycle went in a single run so the graphs show both charging and discharging.


























The resulting IR is due to my connection method of the cells, if using the long tab cells and a connection method I developed and was implemented by a few other people the IR of a 3-4P group results in 0.1mohm or less.


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## rwaudio (May 22, 2008)

So I only have one high power data set so far, so I wouldn't call it conclusive, however the results are exactly what I expected from the low current tests.

This was recorded with the PL6 again, but in monitor mode only.

Cell 1 is the Sinopoly 60, cell 2 is the Sinopoly 100, cell 3 is the CALB 100, cell 4 is the CALB 60. This was simply the easiest way I could connect the cells given the variance in size between all of the cells.










(1)2.972 (2)3.068	(3)3.116	(4)3.022

Above are the voltages from the graph section with the lowest voltage. As expected based on the IR calculated by the PL6, the Sinopoly 60 sagged the most, followed by the CALB 60, Sinopoly 100 and finally the CALB 100.

This was at 600 battery amps on the JLD404, SOC was 100% at the beginning of the log.

My initial real world impression of the Sinopoly's is that they aren't that far behind CALB in a power application, I will get more data at different SOC, and if possible different temperatures.


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## EVfun (Mar 14, 2010)

Wow, that is 10C on the 60 amp hour cells? I'd expect my 60 amp hour late Thunder Sky cells to drop below 2.5 volts at 600 amps. Perhaps not right off of the charger, and perhaps not if they where warm enough, but 10C is not available to me. That sag (2.97 volts) is about what I'd expect at about 220 amps. 

Don't listen to my wife... please keep up the tests... I'd like to see how they do around 50-60% SOC since that is about where I test mine. I may _have_ to buy some new cells.


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## rwaudio (May 22, 2008)

EVfun said:


> Wow, that is 10C on the 60 amp hour cells? I'd expect my 60 amp hour late Thunder Sky cells to drop below 2.5 volts at 600 amps. Perhaps not right off of the charger, and perhaps not if they where warm enough, but 10C is not available to me. That sag (2.97 volts) is about what I'd expect at about 220 amps.
> 
> Don't listen to my wife... please keep up the tests... I'd like to see how they do around 50-60% SOC since that is about where I test mine. I may _have_ to buy some new cells.


Yep, 600A on a 60 with quite impressive results for both brands. This is measuring a single cell though and not the type of voltage you would see as a pack. IE you would NOT have a voltmeter on the dash read 148.5v with a 600A load and a 50 cell pack. There will be more drop in the series connections, fuse, switch, shunt connections and any cable runs to the controller. If you were measuring a single cell in your pack under load it's fair to compare the numbers directly with what I posted above.

I will continue testing when I can, I'd like to do 50% and 20-25% as well.


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