m@Robertson
Well-known member
The actual link was easy to find:Maybe M@ can tell us how this one looks.

48V Ebike Battery 21700 sam/sung/LG Cell 52V 36v Triangle 20AH 25AH Capacity 1500W 1000W Bafang motor Super Powerful 21700 akku - AliExpress 18
Smarter Shopping, Better Living! Aliexpress.com
Samsung/LG 21700 cells which means one or the other. What they are saying in the specs doesn't add up. They list "Peak current" as 80a, which is quite a lot. But then they also list "Max constant discharge current" as only 30a. Thats mighty unusual. An 80a peak BMS is a premium performer. Thats a high performance number. Continuous limit underneath an 80a peak should be around 60a. But they say its waaaaaay down at 30a. That ain't right. One number or the other is bogus. Probably the peak current but who knows when you catch them BS'ing like that?
Also they say the charge cycles are 1600 and we know that is flat out BS. You can fudge battery cycling test methodology to get a number of 1600 but its not an industry standard measure when you do that by any means. 1600 cycles would be achievable (roughly) with a 30% Depth of Discharge, so you charge only to 80% and drain it down only to 50%. That should get you about 1500-1600 cycles. Its total crap to be selling a battery and pretending that it has special "extended cycle life" cells when there is no such thing. So if they are lying about this what else did they put over on you thats not so obvious?

As far as I am concerned everything on AliExpress looks bad. It is a venue where the seller is effectively unaccountable for quality. Pretty much just as bad as Amazon. I buy lots of stuff on Ali, as well as Amazon, but never batteries. The seller can say anything they want. I have seen buyers who were told to ship a battery back to China at their expense for an evaluation, only to be told by the seller (who was UPP) that the pack is fine and then shipped it back to them.
I have also personally bought a pack where I specified Samsung 25R cells, but thats not what was actually provided inside. Counterfeits are commonplace.
- UPP (Unit Pack Power) is loved by many for their low prices but their quality was so horrific they were banned from sale by the UK government, and the US CPSC recommended a stop-use and disposal for anyone who owned one. CPSC also noted UPP refused to do a recall.
- EM3EV is a source in China with a well-deserved good reputation. I don't buy from them personally but they are the standout.
- I do my battery buying these days from Bicycle Motorworks in Pennsylvania. USA built. A 52v 20ah battery costs $664, which is not expensive for a safe, well built battery pack. Puts the $220 battery prices in perspective.