[Sold out] 8 Purple Samsung ICR18650-28A $10 shipped

All packs dated April 2011 all cells with 3.7v . :bigsmile:

Well, using the screw driver to pry the pack didn't really touch the pcb, even though it kind of looks like it did. Just slightly inserted the screwdriver where shown and twist :)

Dremel I am guessing? Nice job btw, but I had to take my apart in the house (I use the built in computer nook area in our apartment for my workshop), with the wife and baby asleep, lol.

Good show, blfdemigod!

moT, how did you peel back the battery “cover”?

Ya nice work on that tut. That’s pretty much how I finally was able to get mine out. So they are on my i4 charging right now. :wink:

Ran the three sides around its corners on bench grinder till it started exposing gap most way around. Then went a couple shallow passes on the round side opposite the connector to give it a bend point.

Awsome Job blfdemigod with hand tools.

My first thought was hack saw it slightly in the middle and snap it in half then decided it be better to spew plastic filings all over the garage floor using the bench grinder.

Maybe I should take the pack to my dentist ?! :bigsmile:

What cells could be in here?
6 cells - 4400 mAh

and THX to moT and blfdemigod for their nice pics

They call it a battery for a Dell, not an original, authentic Dell. So it probably has junky “UltraFire” type cells in it.

thank you for the guide demi god… i would have never been able to open this thing without it

it seems i nicked the wrapping of EVERY battery… beginners luck!

i covered any gouges with elec tape for now… i guess ill invest in some wrappers from illuminationsupply soon to rewrap the cells

charging them all up now

how do you guys remove the 4 burrs that are left at each pole? or do you leave them there?

i guess i just worry about a small piece of metal becoming dislodged and causing a short.

That would have 2 banks of 3 cells in series. so 4400mAh/2 = 2200mAh cells

Based on the description I’d agree 100% with dchomak, it is a cheap aftermarket replacement and will have inferior cells. But, not all aftermarket replacements use cheap cells. It the states we have brands like Denaq or Maxcapacity that are quality replacements using high quality cells. Check out this interesting video of a battery factory tour. At one part they speak of a Polish branded pack using panasonics…

No problem, I was like wow this pack is impossible to open compared to all the other packs I ever opened. For the metal burrs on the end, I used my dremel and slowly sanded them down, then used my hft stick polish and the dremel cotton buffer disc and made it nice and shiny! Better than brand new looking!

What’s the capacity of this 4.35v battery when charged with 4.2v charger?
Is this equation not applicable?

2800 mAh * (4.2/4.35) = 2703 mAh — only 100 mAh less

No, look to this site for the reviews: Test of Samsung ICR18650-28A 2800mAh (Purple)

Essentially they are really approximately 2600mAh, and when charged to 4.2, approximately 2400mAh.

No. The battery isn’t flat at 0V and the discharge curve isn’t linear.

Look at some of HKJ’s battery reviews, he actually shows the amount of current (and also energy) batteries put out when discharged at different rates. For 4.35V batteries, he shows that information for the battery charged to 4.35V as well as for the same battery charged to 4.2V.

Thanks B42, GregY.

According to the linked page, this is not 2800 mAh but
2600 mAh w/ 4.3v, and 2400 mAh w/ 4.2v.

Under ’Test with 4.2 volt charging”:
When only charging to 4.2 volt the battery looses about 220mAh in capacity.

[EDIT]
HKJ
09/20/2012

Test / Review: Samsung ICR18650-28A 2800mAh (Purple)

Just finished capacity results on the first 2 batteries.Both charged to 4.16 volts with the i4 charger. I used the LittoKala Engineer 260 for discharge capacity and internal resistance and results are very good.
Battery 1 IR = 53 and 2380 MAH
Battery 2 IR = 51 and 2409 MAH

I’m not sure how accurate the IR numbers are from this LittoKala battery tester,but brand new panasonic cells are in the same range as these batteries.My conclusion is that these batteries are slightly better than the Panasonic CGR18650CG that I got last week.They measured 2210 MAH and in the low fifties IR values.I do have some very old sony laptop pulls that are supposed to be 2250 MA and only measure 1100 MA and the IR values are over 100.

moT -> GENIUS w/ that bench grinder suggestion!

I’m really glad I happened to read ur post b4 opening my pack w/ hand tools. After reading ur post I went to my grinder & ~15 minutes later (probably took that long b/c I kept checking to not grind too deep into the pack) the pack opened up like a can of sardines! My fingers especially thank you (probably my last pack was a real boar to open w/ hand tools.) I didn’t open up the pack any further after getting the plastic shell open. I’ll save that for tomorrow when I’m fresh and alert.

Anyhow, great call on using a grinder. :slight_smile: I’m definitely going to use these method for opening pretty much ALL future packs.