Search found 120 matches

by Dak77
Oct 19 2020 2:06am
Forum: Battery Technology
Topic: Absolute best 18650 (cycle life, DCIR)
Replies: 21
Views: 675

Re: Absolute best 18650 (cycle life, DCIR)

For 1C loads, MJ1 are normally among the best you can buy for cycle life. For anything over 4A per cell continuous, the HG2 is going to last longer . And yes in either case, .2C charge rate is your best bet if possible. Yeah, then the hg2 is better for me, for only a small loss in capacity. The qui...
by Dak77
Oct 18 2020 11:28pm
Forum: Battery Technology
Topic: Absolute best 18650 (cycle life, DCIR)
Replies: 21
Views: 675

Re: Absolute best 18650 (cycle life, DCIR)

Over the last two years, I've built equivalent packs from both mj1 and hg2 cells. The mj1 pack had a little more capacity at first, but has not held up over time. It's fading fast after only 100 cycles. But the hg2 pack is older and still going like new. I thought the mj1's we're supposed to have a...
by Dak77
Oct 18 2020 11:16pm
Forum: Battery Technology
Topic: M29&M36 in stock as of 10/18/2020
Replies: 0
Views: 283

M29&M36 in stock as of 10/18/2020

18650 - bulkbattery.com LG M36 and M29 @ awesome prices in bulk right now for US customers . They're often out of stock so just thought I'd give a heads up. These are 2 of the best ebike batteries available for moderate amp loads, depending on your application.
by Dak77
Oct 05 2020 1:22am
Forum: Battery Technology
Topic: bunk? 30Q/141 cycle test
Replies: 19
Views: 876

Re: bunk? 30Q/141 cycle test

It just seems odd that a rip off operation wouldn't follow the usual format of Samsung SDI labeling, but would bother to print under the wrapper at all.
by Dak77
Oct 05 2020 1:02am
Forum: Battery Technology
Topic: Deciphering new Samsung 18650 date codes
Replies: 12
Views: 337

Re: Deciphering new Samsung 18650 date codes

R3E1 ....
possibly Revision 3
A=2015 B=2016 C=2017 D=2018 E=2019 F=2020
1= month 1 (January) etc ? just a guess
by Dak77
Oct 05 2020 12:54am
Forum: Battery Technology
Topic: Deciphering new Samsung 18650 date codes
Replies: 12
Views: 337

Re: Deciphering new Samsung 18650 date codes

I still haven't found the "key" for reading recent 30q date codes or where they're even at, but the listings @ https://liionwholesale.com are labeled the same way as yours. Samsung is making it a pain to see info customers shouldn't have to dig for. That said, I wouldn't assume they're fak...
by Dak77
Oct 04 2020 1:55am
Forum: Battery Technology
Topic: Deciphering new Samsung 18650 date codes
Replies: 12
Views: 337

Re: Deciphering new Samsung 18650 date codes

under the wrapper maybe now?
by Dak77
Sep 23 2020 2:44pm
Forum: Battery Technology
Topic: Not quite a Satiator, but $89 delivered!
Replies: 8
Views: 487

Re: Not quite a Satiator, but $89 delivered!

If this is the same company that made the VW , Audi, etc early oxygen sensors (Lambda Probes) , they are probably high quality, no doubt.
by Dak77
Jul 30 2020 4:31pm
Forum: Battery Technology
Topic: 40T, neodymium magnets, plasti dip cycle test
Replies: 109
Views: 5695

Re: 40T, neodymium magnets, plasti dip cycle test

I like it. It's giving me some ideas on future builds. I need to get a printer now. Not having to worry about tension due to using those magnets instead of spring type contacts opens up some cool possibilities concerning enclosure design. I could see a pvc tray with a 2 tiered relief for cell then a...
by Dak77
Jul 06 2020 6:57pm
Forum: Battery Technology
Topic: 40T, neodymium magnets, plasti dip cycle test
Replies: 109
Views: 5695

Re: 40T, neodymium magnets, plasti dip cycle test

Were there any signs of the plasti dip breaking down around the stress areas?
by Dak77
Jul 06 2020 5:17am
Forum: Battery Technology
Topic: 40T cycle test
Replies: 26
Views: 1658

Re: 40T cycle test

nice. Not too shabby for such a high amp cell
by Dak77
Jun 25 2020 4:28pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 483
Views: 54314

Re: Li-ion cells cycle ageing

Let me remind LG HG2 No2 : LG HG2 No2, production date November 2017. Purchased fom nkon in September 2018. Cell stored at aprox 25 – 40 % SOC, 15° - 20°C. In December 2018 capacity 2 909 mAh at 3 A discharge, measured at ZKETECH EBC-A10H. In September 2019 : 2836 mAh at 1A, 2804 mAh at 3 A, measur...
by Dak77
Jun 22 2020 12:36am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 483
Views: 54314

Re: Li-ion cells cycle ageing

If there's one thing I learned in the barrage of data I've seen over the past year or so here, it's what NOT to buy. That alone has saved me a lot of time and money. Huge thank you ! to everyone involved .
by Dak77
Jun 22 2020 12:16am
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 483
Views: 54314

Re: Li-ion cells cycle ageing

I'm sure he's going to continue testing cells in the future anyway. Very probably not, cells testing became boring. Vegetable growing is much more interesting and enjoyable. :) 1.jpg 3.jpg Comparing cells tested at different times, by different people with different equipment is impossible. Wrong, ...
by Dak77
Jun 18 2020 8:35pm
Forum: Battery Technology
Topic: 40T, neodymium magnets, plasti dip cycle test
Replies: 109
Views: 5695

Re: 40T, neodymium magnets, plasti dip cycle test

Since you're into the more obscure cell testing, another future consideration , maybe a Queen Battery qb26800 . If that thing has even decent cycle life , it would be very interesting. I saw that battery here, Thunderheart did it but something turned me off of it? probably because they wouldn't sel...
by Dak77
Jun 18 2020 1:40pm
Forum: Battery Technology
Topic: 40T, neodymium magnets, plasti dip cycle test
Replies: 109
Views: 5695

Re: 40T, neodymium magnets, plasti dip cycle test

Since you're into the more obscure cell testing, another future consideration , maybe a Queen Battery qb26800 . If that thing has even decent cycle life , it would be very interesting.
by Dak77
Jun 18 2020 1:35pm
Forum: Battery Technology
Topic: 40T, neodymium magnets, plasti dip cycle test
Replies: 109
Views: 5695

Re: 40T, neodymium magnets, plasti dip cycle test

I like the work you're doing . Would have never given magnets a serious thought until now. thanks, the 40T cycle test im doing in the other thread is using 3/8x1/8x1/8 ring magnets to see if they last. ive got a molicel p42a coming and im going to use these new magnets with the slug tape on that cy...
by Dak77
Jun 16 2020 7:34pm
Forum: Battery Technology
Topic: 40T, neodymium magnets, plasti dip cycle test
Replies: 109
Views: 5695

Re: 40T, neodymium magnets, plasti dip cycle test

I like the work you're doing . Would have never given magnets a serious thought until now.
by Dak77
Apr 29 2020 5:56pm
Forum: Battery Technology
Topic: Li-ion cells cycle ageing
Replies: 483
Views: 54314

Re: Li-ion cells cycle ageing

If there's a website or forum with this type of in- depth cycle testing by equally competent observers, I haven't seen it yet. There's Mooch and Thunderheart with their load/capacity/temperature/resistance measurements, but it seems you are of the very few (possibly the only ones in the world) doing...
by Dak77
Apr 25 2020 11:01pm
Forum: Battery Technology
Topic: Queen Battery QB26800 6800mAh 20A - the big guy!
Replies: 30
Views: 4502

Re: Queen Battery QB26800 6800mAh 20A - the big guy!

Being better than something known to be grossly overpriced, of very poor quality or known to be fraudulent, is not a high bar is it. I'm not saying they may not be fantastic for people that are on a budget and don't need much power density. Whether they actually are or not, remains to be seen, when...
by Dak77
Apr 25 2020 7:26pm
Forum: Battery Technology
Topic: Queen Battery QB26800 6800mAh 20A - the big guy!
Replies: 30
Views: 4502

Re: Queen Battery QB26800 6800mAh 20A - the big guy!

john61ct wrote:
Apr 25 2020 3:12pm
Well longevity is one data point that really needs member testing.

But 1C rates likely don't inspire too many among those circles?
For the kW+ riders, probably not. For the run of the mill 500w-750w bikes , they'd make a good replacement for those stupid priced 13-15ah sh*t bricks .
by Dak77
Apr 25 2020 2:35pm
Forum: Battery Technology
Topic: Queen Battery QB26800 6800mAh 20A - the big guy!
Replies: 30
Views: 4502

Re: Queen Battery QB26800 6800mAh 20A - the big guy!

I got the data sheet on this cell, it shows different stats, its 20mohm not 10mohm. 6.8a/ 1c charge/discharge 500x is 80% capacity not 90%. at 3.4a/0.5c charge/discharge 500x is 90% capacity. still a cheap battery though http://queenbattery.com.cn/our-products/684-qb26800-li-ion-battery-cell-qb-268...
by Dak77
Apr 24 2020 2:24am
Forum: Items Wanted
Topic: Tektro Electric Brake Levers with Integrated Bell
Replies: 7
Views: 1573

Re: Tektro Electric Brake Levers with Integrated Bell

did you still need this? i ran across a couple, would need to dig them out and post pics. I recently bought a radrunner to haul my little girl around on and I am wanting to scrap these mechanical disks for some Deore hydraulics . Am I correct in assuming the yellow 3 pin connectors coming from thes...
by Dak77
Apr 22 2020 4:11pm
Forum: Battery Technology
Topic: How long is it safe to use an ebike battery?
Replies: 21
Views: 887

Re: How long is it safe to use an ebike battery?

I'm more asking than stating , but wouldn't testing internal resistance be the clear way of knowing if a battery is still safe? If it's still within a certain percentage range of original DCIR , it hasn't "decayed" to an unsafe point , correct?