Recent content by docware

Battery fire is a nice vivid consequence of idiotic effort of Louis Rossman. rg12, what difference do you expect between the two batteries ? There is a safe voltage difference range for connecting the batteries. Just don´t understand why you are still active on such trials...

Calendar aging test update. Seven cells passed 200 days milestone.

Selfdischarge update. Another two cells from cycle aging test checked (Samsung 29E7, Sanyo GA), both seems to be OK. Then new cells Samsung 30Q No4 and Samsung 40T No3 checked, both have only a few full charge/discharge cycles. It is obvious that even new 30Q No4 (orange chart curve) has...

Here is selfdischarge comparison of 30Q and VTC6. I made some selfdischarge voltage drop measurements on the cells in calendar aging. Obviously at 100% SOC new 30Q has markedly higher selfdischarge than others.

30Q selfdischarge has been mentioned several times in this threat as well as in others. After cycle testing, it was obvious that remaining aprox 90 % capacity of 30Q cell could be used in some not demanding application. So flashlight was my choice. Charging the cell to 3,8 - 3,9 V only...

New update, Samsung 29E7 and LG M50T added.

Assuming the voltage is reading from Daly app. I am not sure if you have chance to recognize possible balancing from voltage reading on the cells, probably not. Even if your charger has really 58,8 V at the output, 58,1 V reading on battery at the end of charging is normal because there are...

Not sure how did you achieve to find this test. :) It is protected cell with protection circuit installed. Moreover the test is from the time, when lygte had non true 4 wire measurement. Those are reasons for the different discharge characteristics, mainly at 5A.

In fact 2,5 V cut-off happened between 37 and 38 min. However temperature logging time was set to 1 minute, the graph didn´t catch the temperature peak. Temperature was already going down at 38 min. For 0,625A peak temp corresponds to 2,5 V cut-off.

I was curious what is Panasonic 18650B real discharge characteristic. Panasonic official data list : My results - I used 5A because of specification 4,9 A max continuous discharging current :

Hillhater, Panasonic 18650A is old cell, old technology. Maybe it is only cell with such pronounced divergence. Moreover, 18650A graph doesn´t look like real measurement. Capacity at 2C isn´t so much higher in newer specification from 2012. We can see similar tendency at some cells. Compare...

You need reliable bullet-proof solution, I can reccomend Higo connectors. https://www.higoconnector.com

I can confirm the probable temperature effect on the capacity, see real measurement on Panasonic 18650B. However, the energy at 3A discharge is lower thanks to the higher voltage drop.

What I found out from 30Q and VTC6 cycling data is that the quick capacity loss at the beginning happened mainly during the first 8 cycles. DOD for both are slightly over 70%. However these are high power cells. For high capacity cells like M36 or 35E I see different picture, where initial...

You probably want to clean aging data with help of data collected from cycling ?