Lithium Ion Batteries - 18650

chillybags on 22/06/2016 - 21:54

Does anyone have much experience with Li-ion batteries? I plan to use the batteries in a trustfire torch i got on ebay. It came with some ultrafire blue batteries and a charger. Read plenty of bad things about the ultrafires definitely going to stay away from them where possible but may use them until some better quality batteries arrive from online. I will carefully monitor the voltage and charging of these batterys (seems the majority of issues are when charging these batteries).

I pulled out some old panasonic CGR18650 HG batteries from an old rechargable portable dvd player. The played would have been bought in around 2006 batteries last charger around 2010 probably. Check and they are still holding 3.8V on them which according to the threads i've read they should still be alright as long as they are above at least 3.0V. Reckon i could use these batteries?

In the next couple of weeks i will definitely be looking to get some new panasonic NCR's and a good quality nitecore charger.

Electrical & Electronics

Comments

  • [Deactivated] on 22/06/2016 - 22:03

    They will be fine to use. I have used batteries pulled from laptops. They function, but are pretty worn out so capacity is about 1/2 what it should be.

    • chillybags on 22/06/2016 - 22:19

      I tested the amps on the battery. Starts at around 5.5A but looses currently quite quickly. Drops by a couple mA per second. Doesnt seem normal that should be pretty constant yeh?

      • elusive on 22/06/2016 - 23:27

        Please don't test batteries like that - when you hook up an ammeter across a battery, that's basically a dead short. Bad for the ammeter, very bad for the battery.

        • chillybags on 22/06/2016 - 23:28

          Oh really, didnt know that. Will not do it again.

        • elusive on 22/06/2016 - 23:34
          +2

          @chillybags: The trick is you need to put the ammeter in series with a load. What you can do is put the battery in the torch with the end cap off and use the ammeter to bridge the connection between the battery and the tube (where the end cap attaches). That will measure actual current draw of the torch (which will be lower than the dead short scenario).

          Do note that Ah rating (capacity) is different from A (current). Capacity is a measure of current over a period of time - one Ah (Amp-hour) is equal to one Amp for one hour. However, the actual runtime of a battery depends on other factors - e.g. if you draw a higher current then the battery will heat up more from its internal resistance and will lose some energy as heat. You can look up discharge curves at different currents.

          Generally Li-ion can maintain a fairly high drain without wasting much.

  • scrimshaw on 22/06/2016 - 22:27
    +1

    2 years ago I bought some 2x unprotected LG cells from Fasttech for about $11 USD shipped. 3000mah capacity (I didn't test) and it works nicely in my DIY powerbank.

    I also bought some cheap UltraCrapFire ones on eBay and I used them in a Cree bike lamp (also 2 years ago). They haven't exploded so far…

    I also had a Nitecore i2 charger but I then upgraded to an Xtar VC2 as it was capable of doing 4 batteries at once. It's priced reasonably and you can get it pretty cheap on Gearbest.

    Remember if you're using li-ions in a flashlight you need to buy ones with protection circuit. For making DIY powerbank you need unprotected ones.

    • chillybags on 22/06/2016 - 22:31

      Yeh i was probably going to pick some up from fasttech will upgrade the shipping hopefully they arrive by the 18th july which is when i really need them by!

      Also im not sure if my cells are protected or not. How do i determine if they are?

      • elusive on 22/06/2016 - 23:43

        Protected cells usually have a circuit board on one end, with a distinctive circular indent in the wrapping maybe 3mm from the end.

        But if you pulled it out of an assembled appliance then the cells are unlikely to be individually protected.

        Protected cells are most critical if you have a torch that takes multiple cells. If your torch only takes a single cell, protected is still better, but less of an issue than multi-cell.

  • elusive on 22/06/2016 - 23:40

    Bad batteries are dangerous, yes. The LG batteries you pulled sound like they should be fine. If you want a cheap option, these Samsung ones off FastTech are decent. (5% off with BLF or CPF codes)

    However, good batteries with bad chargers are also dangerous. A good battery that's overcharged can become a fire or possibly explosion hazard. So make sure you get a good charger, too - and never ever use a "timer" or trickle charger with Li-ion.

    (Timer and trickle chargers are just generally crap, but the consequences of overcharging Li-ion are worse than NiMH/NiCad. More energy = bigger boom.)

    • chillybags on 22/06/2016 - 23:59

      Yep thanks for all the help, much appreciated! Deffs not worth the risk and cheers for the 5% discount too!

  • drogba on 23/06/2016 - 21:05

    I just picked up an OPUS BT C3100 charger to go with my new Nitecore EC11 torch and nitecore 18650 battery. I picked it up for about $40AUD delivered to Perth form gearbest. I was going to post the deal here on Ozbargain but apparently the store is banned. Not sure why though because I had a good experience, only took a week to arrive.

    I'm a bit of a noob with lithium batteries and such but from what I gathered its probably one of the top chargers out there.

    They are still 50% off if your interested..

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