Recent content by derek10

fenix-store
  1. D

    Test/Review of Samsung ICR18650-26J 2600mAh (Pink)

    Thank you for the reviews What does the M mean after 26J? and SDIEM - SDI? I have a Camelion Powerbank which uses a 26H, similar to the one you reviewed but also has the M and SDIEM like your 26J. Is that another model? Thanks
  2. D

    Why do flat batteries use the case as positive instead of negative

    All Li-ion prismatic cells (not LiPo, those seems to use two separate pins and the metallic envelope is isolated) that I saw are so. The small pin at center is negative and the whole case is positive :S
  3. D

    Why do flat batteries use the case as positive instead of negative

    For example most 18650 use the case as negative and the positive as an isolated pin, but some flat batteries are reversed - the metal case is positive and a isolated pin as negative. Why is that? Thank you
  4. D

    Tesla's gigafactory dropping 18650's and going with 20700 - per Elon Musk

    Also many powerbanks. Mine all have Samsung 18650 cells
  5. D

    Tesla's gigafactory dropping 18650's and going with 20700 - per Elon Musk

    I read that cylindrical cells last longer than prisms and pouch cells.
  6. D

    How long do 18650s last if always charged at 4.20v?

    Mine is not as customizable (only the 80% option, no way to change the max charging nor set a minimum threshold to start charging) but when I expect not to use the battery anytime soon, I discharge it to 40% or sometimes less and take out of the netbook and use it only on mains, to keep it away...
  7. D

    Question about storing batteries

    Thanks :) I am talking more about regular Li-Ion batteries, I currently don't have any LiFePO4 powered device :) But if the batteries are new and you monitor them on a regular basis to avoid overdischarge, will storing them below 40% further extends their shelf life? or is 40% just the best...
  8. D

    How long do 18650s last if always charged at 4.20v?

    I have a 6 year old Samsung netbook, which have a function to charge up to 80%, and almost never discharge to 0 and when not in use or plugged in, I store the battery charged from 30-40%, and it's still as good as new, lasting as always (4-5 hours more or less).The battery reports 21% wear...
  9. D

    Question about storing batteries

    Hi I always read to store batteries to 40% (~3.8V) when they are about to be stored for a long time to reduce permanent capacity loss while avoiding overdischarging (less than 3V) due to self-discharge. I saw a test here which can't remember the author nor link in CPF that tested an...
  10. D

    Test/Review of Charger Xiamen Nanfu HG-1412W

    Thank you HKJ very useful like all your contributions as well as your website :)
  11. D

    Test/Review of Charger Xiamen Nanfu HG-1412W

    Would current would go down to 0 sooner or later even if the charger doesn't terminate the charge? or there will always flow current (maybe due to self-discharge?) How does this damage or a Li-ion battery (not counting the applied overvoltage)? Thank you :)
  12. D

    3.8V (4.35V) batteries

    It turns out that there are Li-ion batteries rated up to 4.4V max voltage LOL Next stop: 4.5V
  13. D

    3.8V (4.35V) batteries

    Many thanks for your replies, so seems that 4.35 cells would last as long as 4.2 ones when charged up to their max rated voltage. However, I saw here http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries this graph. I don't know if the cell used there is a 4.2V...
  14. D

    3.8V (4.35V) batteries

    Do 3.8V (4.35V) batteries last as long as regular 3.7V (4.2V) ones? i.e are they prepared to be charged at that voltage? I read that charging a battery to 4.35V will short its lifespan. Many thanks
  15. D

    NiMH battery doing a weird thing

    Thank you, maybe, although I've never saw saw that failure mode (voltage drop then up again:thinking:) always simply losing capacity or IR increase. Nah I think buying a new flashlight would be more cheap because that battery seems to be proprietary... but it seems to be easily replaced,
See more

Latest posts

Top