RoughRider said:
hey guys...this cells have demonstrated their potential...
the 15Ah gave over 400A...so its a 30C cell...this is clear now...
there are no further tests necessary...
@Paul
keep your money...you dont need to make any more testing...
make some capacity-tests @10C charge and discharge and thats it...
Thanks roughrider I appreciate your support. However that cell was actually a 20Ah cell so it's wasn't at 30C, more like 20C. I'm not gonna try to pull the eyes over anyones eyes, what's the point, how long would it be before I was found out??
The 30C that I originally mentioned was a figure that I was given but had never proved and was never written in any documents. I was hoping that tests would have given the actual measured value, but now I will make best efforts to demonstrate the capabilities myself. They will not be continuous current tests due top the nature of my test equipment, but I have enough switches on my test kit to control the current to with say within 20A or so. I had left the tests on the back burner, but now I'll get some clear data for everyone to see.
My feeling is that 20C or a little more continuous discharge is achievable for both cell types and for short bursts considerably more. I will back this up with some tests within the next couple of days and give proof of shunt caliubration by comparison with the 2 current clamps I now have. I think some temperature control is necessary to achieve the very best results but that's not so easy to achieve. Soom cooling is the best I can offer for now. I'm sure there'll be a few headaches getting all these tests done, but I've never been a quitter and will not let problems either big or small stand in my way.
I bought the following test equipment today:
- 2 channel oscilloscope, 1 channel for cell voltage, 1 for shunt resistor with USB connection for data logging.
- 1000Adc stand alone current clamp to confirm current measured on shunt and give proof. A shunt can be anything you say it is.
- DMM with temperature sensing and connection to PC, to log temperature during tests.
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Also have 10pcs of A123 26650s arriving soon for direct comparison.
I'll speak with Cam Light about some test kit and try to get something arranged in the near future.
Also bought some materials for the pack assembly including cooling panels for high current applications. I'm a bit delayed with the pack termination but will be visiting a supplier on Friday which I use for Hub motors who have offered to do the necessary machining for me. The deign is almost there and will make a new post soon with some info on options and construction details.
Thanks for all your patience with this I'll do my best to get it done properly and ASAP