Batteries

[stevoknevo]

Mine have "SAMSUNG 30Q/20A/3000MAH" on the wrappers. Are they not real 30Qs?

I should have said "as stated by Samsung themselves" and ommitted the wrap part - my apologies for the confusion.

It depends where you got your 30q from as I know Fogstar now have the capacity/amp limit printed on their cells - in the header on their site they rate them as a 3000mAh/20a cell but in the blurb below they state a 19a limit with a link to Mooch's site - if you read Mooch's findings he clearly states they are capable of 20a continuous provided they don't exceed 75°C but are correctly specc'd by Samsung at 15a continuous. If Fogstar's 30q are labelled the same way as the 25r that I have from them, then it will state 3000mAh/20a on the wrap as ultimately that is what they are capable of, but, and I quote Mooch, "At higher current levels the voltage sag and power loss in the cell are huge. Do not exceed 20A.
I am giving this cell a continuous current rating of 15A (about 45W using 3.7V) and a temperature-limited rating of 20A (about 60W if using 3.7V) as long as the cell is never allowed to reach 75°C."

I'm surprised you are finding major drop off in the 30q capacity after so few charges? Mooch did a shootout of 30q v Sony VTC6 v LG somethings? - all 3000mAh cells; he 'abusively' tested them by discharging to 2.5v and charging at 4a to 4.2v to replicate circa 200 cycles, the 30q stood up to this the best, and lost less of it's capacity compared to the others.

 

[nwhornet]

Fogstar 30q are marked 20A/3000MAH on the battery. Never had a problem with them in dual/triple cell mods but if you're using them in a single above 50w then you are pushing them (100w in dual & 150w triple) & they will likely sag quicker. Also how do you know the batteries are only holding 2000MAH as a charger only show what it puts in not total capacity as it doesn't know what MAH it was when you put it on charge.

 

[Dozwold]

Also how do you know the batteries are only holding 2000MAH as a charger only show what it puts in not total capacity as it doesn't know what MAH it was when you put it on charge.

You can’t... unless you buy the X Star Dragon battery charger that allows you to completely deplete the battery then charge it. It’s a slow process but that can tell you full storage. However even though it my show you 2000 mah put in, it still doesn’t actually mean the battery is perfect and as good as news, as it could be depleting faster than it used to and no real usable tests for that outside of a lab.. so, I just buy new batteries yearly and make sure I charge them on 1amp rather than 2amp fast charging which helps the longevity.

 

[nwhornet]

You can’t... unless you buy the X Star Dragon battery charger that allows you to completely deplete the battery then charge it. It’s a slow process but that can tell you full storage. However even though it my show you 2000 mah put in, it still doesn’t actually mean the battery is perfect and as good as news, as it could be depleting faster than it used to and no real usable tests for that outside of a lab.. so, I just buy new batteries yearly and make sure I charge them on 1amp rather than 2amp fast charging which helps the longevity.

The question was aimed at @Andy S as he stated his batteries were only holding 2000mah.

 

[Ben fogstar]

The markings under the wrap are normal - they are internal Samsung codes and i'd be worried if they didn't have them. The only way to date a Samsung 30Q is by using the codes beneath the wrap, they differ from most Samsung cells as usually the date/batch code is printed directly onto the wrap. They look perfectly fine to me.

They could be old, lower grade and therefore not be performing adequately. It all depends how long the shop has had them for, how long their supplier had them for before that and also how they were stored.

Lower grade cells are invisible to the end user. One of the industry secrets is that only we as retailers that buy in bulk will ever see the grade of cells as the grade is stamped on the outer boxes. So while we could be cheaper, we'd be offering an inferior product and we're not prepared to do that. We get the best date and the highest grade and we do pay a little extra for that.

We've always pitched our Samsung 30Q as our customer base is primarily vaping. It's very much an on for 5 seconds and then off for 5 seconds. We found that at 20A, with this cycle - the cells will get nowhere near the 75C that mooch recommends their limit up to. However, if we recommending these cells for a battery pack that was a constant discharge down to 2.5V - the rating would be 15A, as that what Samsung actually had in mind while writing their spec sheet.

 

[oldhippydude]

, as it could be depleting faster than it used to and no real usable tests for that outside of a lab..

You can check the voltage when you take the cell off the charger and test the voltage some time later and see how much the voltage has dropped.

Over a few days or a week older cells will drop noticeably compared to new ones.

I have cells of different ages that look the same .
Using this method I can easily tell the older from newer cells and decide which ones are due for retirement.
I use a multimeter but a mod would give you the same info