Endless Sphere

You can also just run higher voltage on the same setup (same controller and same motor). Acceleration will remain the same, but top speed would increase. For ballpark estimate, go from 36V to 48V and you speed increases to 133% of the original top speed (around 32 km/h). I have a small folding 36V e...

Nice !

Saw this on youtube !! Nice!



Shunt mod at 30:00.

Matador

Thanks for the advice Fechter ! Will do. I did balance charge it for 12 hours the last time I fully charged it and then discharged it to 51.6V. Will rebalance everything when summer comes. I check bulk voltage every month too.

Matador

Since we're in the subject and I hear you guys have a lot of experience with BMS. Do you think this BMS is likely to be on that drains cells unequally (example the last 3 cells groups closer to the negative ) ? or should it be alright. I'm currently storing it at 51.6 (avraging 3.68V per cell) Here'...

How many watts of thermal energy does a 3000mah 18650 generate at 1,2,5 and 10C? We need to know the DC internal resistance of the cell you are using to answer this question. To make things even more complicated, DCIR can vary with state of charge... such as in this example for a good old Sony VTC4...

I am researching 18650 cell cooling, one source said that tab cooling prolongs cell life by reaching into all the layers of the battery, is it the same for cylindrical batteries? How many watts of thermal energy does a 3000mah 18650 generate at 1,2,5 and 10C? I found a couple of fun videos of X-ray...

If someone could make this exact 4 wire leads tester with silver plated solid copper terminal and no solder joints, that would be awesome !

I have plans to try and fit as much as possible into one of these. Any one reckon it would be possible to do 14s6p? Failing that maybe 15s5p? I don't need any BMS, or switch or USB, etc. and I'm not afraid to cut away some of the inside of the case if necessary. Cheers Hailong might be too small th...

2.8V is not dramatic, so as long as they do not ever reach below 2.5V, you're good. Learn about your VTC4 cells. CHECK THE DATASHEET which has all the specifications: Specification_US18650VTC4.pdf On that datasheet, you will see that the manufacturer (Sony), specify it's okay to discharge as low as ...

Both. Charge, then discharge. What you want is discharge capacity. Charge capacity is not reliable because all the cells from different packs are not necessarly in the same state of charge (some cells may be 52% charges, some 23%, some 97%). So some will need less charge time to become full. But onc...

Dude, just use 1000 mA (C/2)... It's much faster to test each cells. 500 mA (C/4) will take twice as long and 200 mA (C/10) will take 5 times as long. In any case, the capacity you'll get on your eBike will be slightly different from that you test, whatever the setting, because you'll very likely dr...

Thank me later:
https://endless-sphere.com/forums/viewtopic.php?t=86777

Matador

Bump

I also love these homemade aluminium box...
14S10P, so you'll never have any sort of range anxiety before you butt can't take it anymore:



Matador

I need a TIG welder... that is the solution to all my problems...