Search found 211 matches

by DVDRW
Apr 01 2019 5:30pm
Forum: Battery Technology
Topic: mass life cycle testing
Replies: 33
Views: 1610

Re: mass life cycle testing

Exciting thread. 8) I'm planning to do about the same. But DIY arduino tester controlled via PC software. Data logging to dropbox. Software will look something like this: https://i.imgur.com/ouj2zjL.png Cells waiting: Heter Lifepo4 LG ABB41865 LG GBMG11865 MG1 LG ICR18650-HE2 LG MJ1 Panasonic 18650P...
by DVDRW
Sep 01 2018 12:22am
Forum: Battery Technology
Topic: Good batteries for rebuilding laptop battery pack
Replies: 6
Views: 388

Re: Good batteries for rebuilding laptop battery pack

Replaced the Dell vostro cells voltage still above 2v without disconnecting. Laptop shows not above 7% but still works full capacity charge/discharge 0-100%. NCR18650A cells. So yeah very sneaky chips they are.

Other option are directly powering laptop to AC side with DIY battery and own BMS or smth.
by DVDRW
Jul 13 2018 1:53am
Forum: Battery Technology
Topic: Lightweight lithium battery for car
Replies: 16
Views: 948

Re: Lightweight lithium battery for car

How you implement LVC for car battery? Latching solenoid exist?
by DVDRW
Jul 13 2018 1:31am
Forum: Battery Technology
Topic: Spot welder doesn't work with 0.15mm pure nickel
Replies: 15
Views: 1471

Re: Spot welder doesn't work with 0.15mm pure nickel

I have 787A+ Sometimes If i switch on the welder it welds very poorly. Strangely sometimes when i switch it off and on again then suddenly all welds doing ok. Max is 0.15 pure nickel or barely 0.2mm ni-plated steel. I use multiple layer 0.1mm pure nickel just to be sure. And solder extra copper stri...
by DVDRW
Jul 12 2018 7:42am
Forum: Battery Technology
Topic: Highest capacity 18650 cells
Replies: 68
Views: 5274

Re: Highest capacity 18650 cells

~95% us use about 10 different cells max i think.
I have ~20 different cells waiting for cycle testing over 2 years now. Start testing when i retire from work.
So first test is like aging test running now :)
by DVDRW
Jul 12 2018 5:53am
Forum: Battery Technology
Topic: Highest capacity 18650 cells
Replies: 68
Views: 5274

Re: Highest capacity 18650 cells

LG INR18650-M36 has 3600mAh label just for getting your attention. 3500mAh 35E etc have still bigger capacity in test results and are lighter in weight too! Fake 4K TVs and now THIS, cmon LG :evil: Cycle life is the most important parameter i think but strangely we still have so less information abo...
by DVDRW
Apr 19 2018 2:29am
Forum: Battery Technology
Topic: Cycle Life tests or experience with Panasonic NCR18650GA vs LG MJ1 vs Samsung INR18650-35E
Replies: 26
Views: 3401

Re: Cycle Life tests or experience with Panasonic NCR18650GA vs LG MJ1 vs Samsung INR18650-35E

What you are talking about? PF is 2.3€/qty and you have to buy 540pcs to get this price 29E is 2.14€/qty if you buy 200pcs. Shipping to Europe is always about 15€ even if you buy thousands of them. Tumich sells 29E ~2.10€/pcs inc shipping. Little bit cheaper but buying from Nkon store should be more...
by DVDRW
Mar 10 2018 12:15am
Forum: Items Wanted
Topic: BMS without cell monitoring
Replies: 1
Views: 290

BMS without cell monitoring

Is there any compact BMS that does not have cell level monitoring? Need only monitoring entire pack voltage and LVC/HVC protection. Quality new 18650 never get out of balance (over 2 years already). Cheap cell level BMS-es tends to be Battery Murdering System. If cells not connected it cant be bad f...
by DVDRW
Dec 23 2017 1:15pm
Forum: Battery Technology
Topic: If you are building packs today, which cells to choose?
Replies: 82
Views: 10587

Re: If you are building packs today, which cells to choose?

29E has this very rare LiNiCoO2 chemistry that never seen in 18650 cells. Very curious to know what cells wins cycle test. :)
by DVDRW
Dec 22 2017 1:35pm
Forum: Battery Technology
Topic: If you are building packs today, which cells to choose?
Replies: 82
Views: 10587

Re: If you are building packs today, which cells to choose?

Interesting, have to test this.
But you cant go wrong with 25R cells?
2.35€ @ nkon :)
by DVDRW
Dec 22 2017 10:46am
Forum: Battery Technology
Topic: If you are building packs today, which cells to choose?
Replies: 82
Views: 10587

Re: If you are building packs today, which cells to choose?

Very good 35E price (3.1€) right now from nkon
https://eu.nkon.nl/rechargeable/18650-s ... 0-35e.html
Very curios about cycle life vs PF cell.
In electric car, cycle life matters 7x more!
by DVDRW
Dec 22 2017 4:00am
Forum: Battery Technology
Topic: Homemade Battery Packs
Replies: 1613
Views: 404211

Re: Homemade Battery Packs

by DVDRW
Dec 14 2017 2:00am
Forum: Battery Technology
Topic: 18650 spot welding -how to- ULTIMATE REPOSITORY
Replies: 735
Views: 138936

Re: 18650 spot welding -how to- ULTIMATE REPOSITORY

Pure nickel strip confirmed!
Worlds cheapest?
Image
by DVDRW
Dec 09 2017 11:14am
Forum: Battery Technology
Topic: The 3500mAh heavyweight division: Sanyo NCR18650GA vs Panasonic NCR18650GA vs LG MJ1 vs Samsung INR18650-35E
Replies: 29
Views: 6781

Re: The 3500mAh heavyweight division: Sanyo NCR18650GA vs Panasonic NCR18650GA vs LG MJ1 vs Samsung INR18650-35E

To see cycle test for them is my ultimate dream :o
So then I can decide which goes to my future i-miev 40kWh battery extener.
by DVDRW
Nov 12 2017 12:29pm
Forum: Battery Technology
Topic: 2 wire high voltage battery voltmeters and more
Replies: 2
Views: 403

Re: 2 wire high voltage battery voltmeters and more

Very nice stuff. Ordered BABY brother and Mac Daddy's little brother yesterday. Usually these similiar 100V 10A models require external power and price is higher too ~9$ But if you still need separate external power, Im using these work great 40-320V DC input: 12V https://www.ebay.com/itm/1919815850...
by DVDRW
Nov 07 2017 2:19pm
Forum: Battery Technology
Topic: Homemade Battery Packs
Replies: 1613
Views: 404211

Re: Homemade Battery Packs

Check voltages every 5th charging or so at first. If they get out of balance then add BMS.
My panasonic 18650PF packs 22S18P 14S12P using every day over a year without BMS and still perfectly in balance.
Checking voltages every three months now.
by DVDRW
Sep 25 2017 4:01am
Forum: Battery Technology
Topic: problems with cheap DC DC boost supplies for charging?
Replies: 1
Views: 331

Re: problems with cheap DC DC boost supplies for charging?

Mine has problems too. Current is not constant. Decreases when charging battery. Maybe because im using it to 92.4V (22S) output
~55V Offgrid 14S input.
by DVDRW
Sep 23 2017 3:22pm
Forum: Battery Technology
Topic: dc dc cnverters, 12-80V -- where??
Replies: 9
Views: 785

Re: dc dc cnverters, 12-80V -- where??

There is also fake LM2596HV-s araound (blow up at ~50V), so be careful.
https://www.youtube.com/watch?v=JLwJb4MVbls
by DVDRW
Sep 22 2017 12:18pm
Forum: Battery Technology
Topic: dc dc cnverters, 12-80V -- where??
Replies: 9
Views: 785

Re: dc dc cnverters, 12-80V -- where??

http://www.ebay.com/itm/172860794791
72v and up is for AC adapters territory.
by DVDRW
Sep 20 2017 7:20am
Forum: Battery Technology
Topic: reasonably priced 0-60V power supply? ~10A or more
Replies: 1
Views: 260

Re: reasonably priced 0-60V power supply? ~10A or more

It's all about mass market.
Only cheap way = DIY
by DVDRW
Sep 16 2017 10:13am
Forum: E-Bike General Discussion
Topic: 48V vs 72V
Replies: 25
Views: 2975

Re: 48V vs 72V

Motor: Magic pie2 (internal controller) Battery: 16S Lifepo4 (52V) Speed tailwind: ~45km/h Power: ~1000W Upgrade to external Lyen 12fet controller Added 3-speed switch so no no jerky at slow rides. Battery: 22S Lion (79V) Speed without wind 60km/h Speed tailwind 74km/h :mrgreen: Power: 2700W (Progra...
by DVDRW
Sep 14 2017 4:00am
Forum: Battery Technology
Topic: Anybody have experience with Sun-Ebike.com?
Replies: 4
Views: 566

Re: Anybody have experience with Sun-Ebike.com?

Lifepo4 is twice heavier, twice volume than INR. So only good for home energy storage.