johnnyz
1 kW
Have not been on here in a long while...thought I would begin posting my new battery build, trying to learn on my previous build of last year.![rsz_20180427_154812.jpg rsz_20180427_154812.jpg](https://endless-sphere.com/sphere/data/attachments/132/132316-cdea8475b4ddf11702a91dedd4e36527.jpg)
I modified an Emmo Zone for performance. I replaced the motor with a QS Motor 16 inch 6000 watt V3 , which has proven to be reliable and very very fast despite pulling 18000 watts.
Controller is a Kelly / QS type that is 300 amp capable. I had it limited to 240 amps for my last battery and setup.View attachment 8
The battery was a 24s14p made from Samsung 25r cells. View attachment 7
Even though I was able to pull 230 or so amps from this, I had huge sag at full throttle and off the line. 96 or 97 volts and would sag to 84 or so...cruising at 50 kph would only sag about 2 volts.I used 2 8 gauge wires for both the positive and negative and for the busbar in the battery (for series) I used 2 10 gauge solid core wire and soldered a thin 18 gauge wire to all the cells in parallel.![rsz_20180220_141543.jpg rsz_20180220_141543.jpg](https://endless-sphere.com/sphere/data/attachments/132/132317-7e425f920f3e2bfd4dfe6e325ba42b1e.jpg)
After talking to an electrician, he thought that the pack and positive and negative cables were far to light in gauge and suggested that the battery sag was mostly due to not being thick enough. He suggested no.1 wire and on the series connection for the batteries, I have spiral Copper equal to about 5 gauge.View attachment 5
...You can the difference between the 2 8 gauge wires and the one no.1 wire.
Even though I had about 140 cycles on the old pack the cells still had 91% capacity, probably because I never fully charged the pack up and usually only let it get to about 3.5 or 3.6 volts per cell (about 86 volts) before charging again. However the actual ah's I was getting out of the pack was about 60%. I am guessing that resistance was the main culprit, and hopefully with the Samsung 30Q cells rated at 3000 mah will be much better and with the bigger wire give me much better efficiency.
While I am waiting for the 440 cells to arrive I designed and 3d printed the cell holders and am putting them together so that they fit neatly in the case..the white cardboard represents the case dimensions..![rsz_img_20190109_135146.jpg rsz_img_20190109_135146.jpg](https://endless-sphere.com/sphere/data/attachments/132/132319-ec21ff1637d2ae838c9a116cce4d713d.jpg)
![rsz_img_20190108_211458.jpg rsz_img_20190108_211458.jpg](https://endless-sphere.com/sphere/data/attachments/132/132320-9be278a315b858c6a649db4627706d72.jpg)
View attachment 1
Ive soldered the wire for the parallel group to the main series wire via small torch so I know its on there, and soldering to the cells only takes less than a sec per cell, as I have a professional soldering gun.
Top speed last year was about 120 KPH and 0-100 was about 6.7 seconds.
Much more to come as I progress....suggestions are welcome...
![rsz_20180427_154812.jpg rsz_20180427_154812.jpg](https://endless-sphere.com/sphere/data/attachments/132/132316-cdea8475b4ddf11702a91dedd4e36527.jpg)
I modified an Emmo Zone for performance. I replaced the motor with a QS Motor 16 inch 6000 watt V3 , which has proven to be reliable and very very fast despite pulling 18000 watts.
Controller is a Kelly / QS type that is 300 amp capable. I had it limited to 240 amps for my last battery and setup.View attachment 8
The battery was a 24s14p made from Samsung 25r cells. View attachment 7
Even though I was able to pull 230 or so amps from this, I had huge sag at full throttle and off the line. 96 or 97 volts and would sag to 84 or so...cruising at 50 kph would only sag about 2 volts.I used 2 8 gauge wires for both the positive and negative and for the busbar in the battery (for series) I used 2 10 gauge solid core wire and soldered a thin 18 gauge wire to all the cells in parallel.
![rsz_20180220_141543.jpg rsz_20180220_141543.jpg](https://endless-sphere.com/sphere/data/attachments/132/132317-7e425f920f3e2bfd4dfe6e325ba42b1e.jpg)
After talking to an electrician, he thought that the pack and positive and negative cables were far to light in gauge and suggested that the battery sag was mostly due to not being thick enough. He suggested no.1 wire and on the series connection for the batteries, I have spiral Copper equal to about 5 gauge.View attachment 5
![rsz_img_20190109_120021.jpg rsz_img_20190109_120021.jpg](https://endless-sphere.com/sphere/data/attachments/132/132318-2fb3a247121c4af396746eb8db1c3b65.jpg)
Even though I had about 140 cycles on the old pack the cells still had 91% capacity, probably because I never fully charged the pack up and usually only let it get to about 3.5 or 3.6 volts per cell (about 86 volts) before charging again. However the actual ah's I was getting out of the pack was about 60%. I am guessing that resistance was the main culprit, and hopefully with the Samsung 30Q cells rated at 3000 mah will be much better and with the bigger wire give me much better efficiency.
While I am waiting for the 440 cells to arrive I designed and 3d printed the cell holders and am putting them together so that they fit neatly in the case..the white cardboard represents the case dimensions..
![rsz_img_20190109_135146.jpg rsz_img_20190109_135146.jpg](https://endless-sphere.com/sphere/data/attachments/132/132319-ec21ff1637d2ae838c9a116cce4d713d.jpg)
![rsz_img_20190108_211458.jpg rsz_img_20190108_211458.jpg](https://endless-sphere.com/sphere/data/attachments/132/132320-9be278a315b858c6a649db4627706d72.jpg)
View attachment 1
Ive soldered the wire for the parallel group to the main series wire via small torch so I know its on there, and soldering to the cells only takes less than a sec per cell, as I have a professional soldering gun.
Top speed last year was about 120 KPH and 0-100 was about 6.7 seconds.
Much more to come as I progress....suggestions are welcome...