I guess the self-balancing is fine when new - it’s when the resistance levels of the cells vary that it would possibly become a problem -> try not to bang my batteries around.
I had an old 5 cell Makita pack go bad with less than 10 charges (one cell reportedly will self drain and then the pack will not recharge you don’t regularly recharge them). Perhaps the balance updates help avoid the non-recharge problem? Anyway, took it by one of their factory shops where they can read recharge info on their packs - they did a free exchange with a 10 cell - happily I now know it has the star and new wiring - thanks for that info! Will be interesting to compare old and new 10 cell packs as they age.
I just read through this thread and wanted to say that I have some Sony US18650GR 18650 laptop pulls (N.O.S. HP 9 cell Pack) that seem to discharge down to about 4.1V after I charge them up to 4.2V. I just noticed this behavior a week ago. I wonder how much capacity I'm losing with them self-discharging down to 4.1V. I did a capacity test (from 4.2V) on my new OPUS and got about 2600mAH on two of them. Interesting that others are seeing the same behavior on similar Sony's.
Nice of you to join the thread Garry.
I must point out though that the Sony’s we’re talking about are drill pack IMR’s
wight you asked me earlier how I handled rummaging through the recycle bins and I gave you my answer. However, a couple of days ago I got caught off guard. While I was poking around in one at HD, I heard one of the girls behind the returns desk ask me what I was doing.
I looked up and dead panned “I’m looking for an old sandwich or something, I haven’t eaten in a couple of days!” She looked at me and laughed and said “Oh there was a half in there earlier, but I already ate it” We both laughed and I went back to my business. :bigsmile:
I pulled out these 2 brand new Ryobi packs, thrown in the bin by HD. I haven’t taken the 10 cell pack apart yet, but it reads 17.65V or an average of 3.53V per cell. The 5 cell pack had 1 dead cell, the other 4 at 3.61V. I don’t know if it was just a bad cell, or that channel on the BMS leaks. I see either all the time.
2 days ago at Lowes I found an unopened 8 pack of Duracell AAA’s. The date on the pack was 2012 and they are 7 year cells. The only thing I can think of is that someone thought that date was an expiration date, like on food. Got them just in time, yesterday 2 of my remotes needed new cells’
That is Lowes parking stripe in the background, shot this outside in the lot.
I recently came up with a lion Makita battery pack while diving in a Home Depot recycle bin. While researching the Sony 18650v batteries inside I came upon some good reading on these "konion" Sony IMR cells and their rumored self balancing properties. I don't understand it fully so I will just suggest any interested parties google search "konion self balancing" and read what the folks at endless-sphere.com have to say on the subject.
The Best Buy near me has elaborate recycling bins, with a rubber flap “valve” and a sloped baffle, and its right by the front door 6 feet from the loss-control guy. I need to find some places with more accessible bins. I haven’t seen any at Home Depot, and they aren’t listed on the county’s list of battery recycling locations.
A friend of mine, not a member here, but into flashlights none the less sent me these pics of a 40V Kobalt battery pack that HE found in the Lowes recycle bin. It was only half full with only 10 cells. The cell info is scribbled onto a piece of paper on the desk. The pack claims to be 2.0AH, that would mean those are 2000mAh cells. He claims there is also a 4AH version of this pack, so that one would be full with 20 cells.
This pack, like the one I found appears to be brand new
Walk in like you own the joint and help yourself. My Best Buy is set up identical to yours. The absolute worst thing that can happen is you will be asked to leave. Who cares what anyone thinks or cares, you are a battery junkie and have to get a fix…… NO Guts NO Glory NO Batteries!
I found the ultimate item in the recycle pile today… a small metal box that ENDLESSLY chants Hare Krishna mantras… 6 different ones, selectable by a button.
It has a line cord coming out that has round pins on it… probably 240V. Digging out my plug adapter I verified that it does not work on 117V. Opening it up revealed a power supply with center tapped transformer, two diodes, and a capacitor. Voltage out was 2.2V. I replaced the two diode/center tap connection with a full bridge connection. Yipee!
hare kṛṣṇa hare kṛṣṇa
kṛṣṇa kṛṣṇa hare hare
hare rāma hare rāma
rāma rāma hare hare
hare kṛṣṇa hare kṛṣṇa
kṛṣṇa kṛṣṇa hare hare
hare rāma hare rāma
rāma rāma hare hare
hare kṛṣṇa hare kṛṣṇa
kṛṣṇa kṛṣṇa hare hare
hare rāma hare rāma
rāma rāma hare hare
hare kṛṣṇa hare kṛṣṇa
kṛṣṇa kṛṣṇa hare hare
hare rāma hare rāma
rāma rāma hare hare