A random google for the cell name they give finds sales sites like this
Liitokala Lii-50e Imr 21700 5000mah 3.7v 40a High Capacity Protected Flat Top Rechargeable Li-ion Battery+diy - Buy Liitokala Lii-50e 21700 5000mah Rechargeable Battery 3.7v 5c Discharge High Power Batteries For High-power Appliances,21700 Battery,21700 5000mah Product on Alibaba.com
www.alibaba.com
with around $3/cell in bulk.
If the 30Ah pack is 6p 14s (typical 52v) that's 6x14 cells, or 84 cells. Let's say they get the cells cheaper in bulk, so it's only $3 each, that's still $252 for the cells...couldn't sell that for only $250. Even if they paid only $2/cell, that's still $168. Let's say they use a garbage BMS for $10, and only another $20 for the interconnects and cell holders and wires, solder, connectors, etc., and use slave labor for building them, so it only costs them $200 in materials to build it (which I think is too low, I expect it actually costs more than they're selling it for, if it were really made of brand new good cells and other quality materials.
BTW, the attached image from their ad claims an explosion-proof enclosure, which it fairly clearly is not. :lol:
And I'd almost bet that hte pics they show aren't even theirs (not an uncommon practice).
Note their "battery size and weight" listing doesnt' actually give the weight, only the outside (?) dimensions.
They only give one set of limits for all versions of the pack, so they probably all use the same BMS, which either means the higher capacity packs are being limited below their actual ability, or the lower capacity packs are being allowed to be pushed beyond their capability.
Specs and info from their ad:
Product Details:
Brand: Aleaivy
Model: 52V E-Bike Battery
Cell: LiitoKala 21700 5000mAh 3C
Category:Li-ion Battery
Voltage : Peak - 58.8V, working - 52V
Capacity: 15Ah/20Ah/25Ah/30Ah/35Ah/40Ah
Power: 150W-2000W
Cut-off voltage: 49V
Max. discharging current: 60amp
Max Continuous Discharging Amperage: 30Amps
Rated Discharging Amperage: 30 Amps
Charging Current: <5 Amps
Charging Voltage: 42Volts
Battery Size and Weight:
52V 14S3P 15Ah Size:310X65X72mm
52V 14S4P 20Ah Size:310X85X72mm
52V 14S5P 25Ah Size:310X110X72mm
52V 14S6P 30Ah Size:310X130X72mm
52V 14S7P 35Ah Size:310X150X72mm
52V 14S8P 40Ah Size:310X170X72mm
View attachment Aleaivy-52V-ebike-Battery-30Ah-40Ah-21700-Lithium-Li-ion-Battery-Pack-for-1500W-2000W-Electri...webp