The best option for electric-longboard if you have spot welding/soldering skill - high-current 18650 cells. They are long-lasting, hold high current (at 3P+), and the thickness is only 18mm.
18650 cells that are suitable for creating a battery:
- LG: he2, he4, hg2
- Samsung: 25r, 30q
- Sony: vtc5, vtc6
and any other original ones.
If you've decided to design a battery from individual cells, you should think how you're gonna charge it. The most common option is to install BMS on the battery + charger.
There are two possibilities to install BMS:
The advantages of installing BMS only on the charge
- only on the charge: in this case, the discharge of the battery will bypass the BMS
- on charge and discharge: with this connection, the charge and discharge of the battery will be via BMS
: saving space and money, because BMS with low current (5-15A) will suit you. They are cheaper and more compact than their high-current (60A+) counterparts. The advantages of installing BMS on a charge and a discharge
: reinsurance. But it's ambiguous. Since the discharge voltage control is in the ESC itself (and the VESC has settings for current limiting), it reduces the need to control the discharge through the BMS.
Make sure that the BMS you selected has a cell balancing function. This is usually indicated in the BMS description or specifications.