I am looking to build some starter batteries (72V) for myself and a friend on a budget. The cheapest options I have found right now for high power output are the EVE 20P overstock from Battery Hookup at $0.79 per cell (EVE ICR18650 20P 3.6V 2000mAh 30A High Rate 18650 Li-ion Cells - Overstock!) and the EV West Samsung 20R modules at $0.50 per cell (Samsung INR 13S 54 Volt Lithium Ion Battery 20R Scooter and eBike Battery Modules, discussed in EV West Too Good to be True? 50¢ per cell, new and Great deal on battery pack).
The reason for not getting some newer, higher capacity cells is that this is the cheapest way I could find to get adequate discharge current. Target pack output is about 80A discharge for a solid 5kw. With the common 21700's that have about 2C discharge, I would have to make a 40AH pack to get enough discharge current. I don't need the size or the cost of a 40AH pack.
Question: Is there a good reason to get the EVE 20P's over the Samsung 20R's given that the EVEs are more expensive? For the same price, I can get a lot more of the Samsung, and the specs are practically the same.
The main difference I can think of, besides pack teardown annoyance with the Samsungs, is that the Samsung packs are probably much older. However, I don't know how much of an impact this has on the final pack.
Of course, if anyone knows of a comparable deal on HIGH CURRENT 21700s, I'd be glad to hear it! The problem has been I need at least 4C discharge.
(FYI, it is true that I have been very interested in pouch/prismatics such as those from Greentec because of the value; however, for maximum flexibility (pack size), simplicity, and reliability, plus the fact that I need to get a spot welder anyway for something else, I've decided I should probably just go with the tried-and-tested cylindrical cell method.)
The reason for not getting some newer, higher capacity cells is that this is the cheapest way I could find to get adequate discharge current. Target pack output is about 80A discharge for a solid 5kw. With the common 21700's that have about 2C discharge, I would have to make a 40AH pack to get enough discharge current. I don't need the size or the cost of a 40AH pack.
Question: Is there a good reason to get the EVE 20P's over the Samsung 20R's given that the EVEs are more expensive? For the same price, I can get a lot more of the Samsung, and the specs are practically the same.
The main difference I can think of, besides pack teardown annoyance with the Samsungs, is that the Samsung packs are probably much older. However, I don't know how much of an impact this has on the final pack.
Of course, if anyone knows of a comparable deal on HIGH CURRENT 21700s, I'd be glad to hear it! The problem has been I need at least 4C discharge.
(FYI, it is true that I have been very interested in pouch/prismatics such as those from Greentec because of the value; however, for maximum flexibility (pack size), simplicity, and reliability, plus the fact that I need to get a spot welder anyway for something else, I've decided I should probably just go with the tried-and-tested cylindrical cell method.)
