no_ordinary_guy
New member
- Joined
- Feb 5, 2020
- Messages
- 4
hi!
im in the working of making a new power pack, upgrading the old pack from 13s to 16s to be able to keep a target speed that is the limit of my "ev-vespa" the limit is 45km/hr but have a hard time even driving 30 uphill. that aside.
the pack it self is a 16s and between 12-14 pr cell.
got around 500 cells mostly from electric bicyle.
the current draw from the factory is 33amp at nominal voltage 48V. at 12 cell row. giving a draw of 2.75A each cell on average.
the target is about 30-33amp at 60V nominal. so we are talking about 2.75amp draw pr cell at worst. and at best. 2.14amp on average.
most cells is about 2200mah each. so we are little over 1c of discharge. would there be any problems mixing cells from mostly samsung, sanyoand some unnamed brand that don't have any cell type writen on them.
sanyo: UR18650ZYT25A
samsung: N18650k P030
samsung: ICR18650-22F
to name a few
a guy that works with powerpacks for bicycle saids i should never mix brands and last 3-4 letters/numbers like T25A and P030 should never be mixed in the same cell in parallel.
what are you guys thoughts?
i test all cells for heat, capacity and internal resistance.
what i figured. if i mix the cells so every row has as close as possible of capacity using the tools this forum got. and don't go above 2.5A each cells. i should be pretty safe. and also check the data on the cells to make sure they are testet at this draw. or should i get another tester to see how the cell would react to this load?
im in the working of making a new power pack, upgrading the old pack from 13s to 16s to be able to keep a target speed that is the limit of my "ev-vespa" the limit is 45km/hr but have a hard time even driving 30 uphill. that aside.
the pack it self is a 16s and between 12-14 pr cell.
got around 500 cells mostly from electric bicyle.
the current draw from the factory is 33amp at nominal voltage 48V. at 12 cell row. giving a draw of 2.75A each cell on average.
the target is about 30-33amp at 60V nominal. so we are talking about 2.75amp draw pr cell at worst. and at best. 2.14amp on average.
most cells is about 2200mah each. so we are little over 1c of discharge. would there be any problems mixing cells from mostly samsung, sanyoand some unnamed brand that don't have any cell type writen on them.
sanyo: UR18650ZYT25A
samsung: N18650k P030
samsung: ICR18650-22F
to name a few
a guy that works with powerpacks for bicycle saids i should never mix brands and last 3-4 letters/numbers like T25A and P030 should never be mixed in the same cell in parallel.
what are you guys thoughts?
i test all cells for heat, capacity and internal resistance.
what i figured. if i mix the cells so every row has as close as possible of capacity using the tools this forum got. and don't go above 2.5A each cells. i should be pretty safe. and also check the data on the cells to make sure they are testet at this draw. or should i get another tester to see how the cell would react to this load?