Just ordered HITHIUM 280Ah from Amy and I couldn't help myself to test them.
The cells arrived 50 days after placing the order (I'm UK based).
The cells arrived ultra flat in shape Hmmm….actually concave :) - which is great.
A quick look at the sticker: 280Ah and 0.21mOhm (ok ,we'll see… ;) ). Blue foil round each cell - traditionally, glued on the sides, down the cells. No damages etc.
So, a quick look and on the bench. Tester show Voltage 3.26V and ……0.18/0.19 mOhm internal resistance. No shit, definitely lower than the manufacturer declares (tester been calibrated and done it twice to be sure). Well, now we know a bit about the number of cycles, it will be higher than given in the catalogue (due to real lower internal resistance). And the catalog says it's ESS class (Energy Storage System). So solar class, not class A (Automotive / for vehicles). I think: well, I won't be powering Tesla with this bank :) They are supposed to be used as an energy storage in a PV installation, not as an HSEV. So for me it sounds.
A quick look at the final bill - yeah zthey are much cheaper than EVE. So, quickly connected to the tester and charged to full (3.65v). After charging, it's time for the “resting stage”. So they got a few hours of “rest”. Discharge setting to 2.50v, 40A discharge current and off we goooooo .., During this phase I checked the amount of energy drawn in relation to the voltage several times. Halfway through the test I knew what would happen. And after a few more hours I had the result - and ….it happened :)
The cell discharged to 2.69v and showed not 280Ah as the manufacturer stated but almost 300Ah (!!!) THREE HUNDRED …. or more precisely between 297 and 301Ah (tested on 2 of 4 cells so far).
Well, I thought: this will cause a stir! Especially since from 2.69v to the very bottom, there was still a little bit of energy left in them.
After the discharge phase and a momentary rest, I charged the cells again to 3.26v and harnessed them to the 4s system. Fully charged by the solar moot charge controller and GO ! Up to 190A of discharge current, the cells did not show any major changes (and I remember when I tested other cells ages ago from different supplier /different products and with loads of 0.5c the voltage on the cells dropped below 3v within a few minutes!). But these here , however, work lightly, without getting out of breath even under massive loads. A few hard tests and the cell temperature was normal (difference of 1°C). BMS, on the other hand, was heating up and sweated :) The voltage on the cells did not drop below 3.1v (!) To sum up: in my opinion, a cheap one with a good perspective and excellent capacity. Based on the internal resistance, you can already predict the number of cycles (roughly ) with normal use (up to 0.5c). For this money? I don't know if it makes sense to compare them with, for example, EVE V2 …. which have similar resistance and lower capacity and cost 60-70% more. Ok, you can install EVE in your car/quad or anything else with a high, momentary demand for energy. But it is supposed to store energy from solar panels and give it back when I need it. And it will be used only for this purpose.
I know that many people have been waiting for this test. I know that many people would be willing to buy such, if someone tested them before buying.
So the cells have been tested. They simply behave very well.
Cells ordered from DOCAN POWER. Purchased not on Alibaba but directly from this company's agent - AMY.
The long-awaited by some people from the groups - REPT 280Ah flew for the next test.
As usual, any constructive comments are very welcome :)
Edit: someone will say - if it's so good, I'll buy it from another seller on Ali (cheaper or more expensive). Of course, go ahead - it's your money and do whatever YOU want with it. . I just want to make sure that in two months someone doesn't scribble under my post that they bought “the same thing but from different supplier” and the cells don't keep their parameters. I'm not responsible for the test results of other sources, ( I've tested several of them apart from DOCAN). Each supplier represents a “little” ;) different level of quality. Please keep that in mind. Oh, and I'm not saying that DOCAN has the best stuff in the world. I just tested them and ……it comes out what comes out. So in my opinion ? Yeah DOCAN IS ! Thank you :)