LG HG2 Batteries and an Interesting Experiment

The third type of battery sent to me by one of my regular readers. I originally planned a thoroughly routine review, since what could I possibly say about such well-known batteries as the LG HG2? But, quite unexpectedly, an ordinary review of ordinary batteries turned into an interesting experiment. As always, more after the jump.


I won't include the datasheet; it's easy to find by searching the blog, and anyone who uses batteries from this manufacturer probably knows it well already.
Roman sent me 4 of these batteries. From what I gathered in our conversation, he bought them at Gearbest quite a while ago—probably back when the store only sold its own products and was one of the places I recommended for buying genuine items. I should know: I bought quite a few batteries there myself, precisely because they were genuine.
The link in the title goes to the Nkon store, but I have also linked before to a decent store on AliExpress, where there's a pretty good chance of getting genuine batteries.


Time moves on, and unfortunately things are different now. But let's not dwell on the sad stuff and get on with the review.
So, four batteries—the usual “chocolate bars.”


Inspection showed that although all the batteries were made in mid-2017, one of them came from a different batch. For that reason, I used batteries from different batches for the tests that followed.
As far as I know, LG's production runs are not very large, so the batteries' “sameness” can serve as an indirect indication of whether they're genuine. But if they were bought from the same place and out of the same box, they're probably from the same batch anyway.
They look completely genuine, though in this case I had no doubts about that to begin with.


Dimensions and weight.


Later, though, it turned out that the difference between the batteries was much more significant. The battery from the “other” batch was completely discharged. The person who sent them to me doesn't remember exactly what happened, since they had just been sitting around after his test. But I'll hazard a guess: three were charged, and the fourth was simply forgotten.
So one battery ended up sitting discharged after testing. I can't say for sure, since it's impossible to reconstruct what happened, but that seems very likely. And that's what prompted this little experiment: comparing the characteristics of batteries made and bought at the same time, but stored in a discharged and a charged state.
Even at the initial stage, during my “conditioning” cycle, you can see that at a 1 A charging current, the first battery is only at 3.16 V, while the second has already entered CV mode.
At the same time, the first battery delivered more capacity than the second at a 0.5 A discharge current.

From here on, the first battery was stored discharged, and the second charged.


Charging went pretty much as usual: 2 hours 7 minutes at 0.5C and 1 hour 20 minutes at 1C.


Discharge of the first battery at 0.2C, 0.5C, 1C, 2C, 10, 15 and 20 A.


Temperature at discharge currents of 10, 15 and 20 A, discharged to 2.5 V in a single run.


The second battery, with exactly the same test conditions.


The temperatures are pretty much the same, with differences within the measurement error.


Now for the most interesting part: a comparison graph at 0.2C, 10 and 20 A. The first, discharged battery is shown in blue, and the second in red.
In every test, the first battery clearly has more capacity. In all the tests, though, capacity is about 120–150 mAh lower than that of the new batteries I showed in a recent review.


However, the batteries have different internal resistance.
Results as received, after “conditioning,” and after all the tests. The resistance changes, but it's clear in every case that the battery that arrived charged has higher resistance. The results for the other two batteries from the same batch are almost identical to the one shown below. In other words, three of the four were charged and have similar internal resistance; the fourth was discharged, and its results are different.


I won't draw any conclusions or claim that batteries are better stored discharged; I simply don't have enough data for that. Ideally, I'd run this experiment myself: take two batteries, measure their characteristics, discharge one, put it away for a couple of years, and then test it again. But I think we all understand that few people would actually conduct experiments like these.

I’d also like to hear what you think: could this difference in results be due to the batteries having been stored in different conditions, coming from different production batches, or self-discharge?
That’s all from me. I hope you found the information interesting.