Rechargeable batteries for flashlight

Discussion in 'General Electronics Chat' started by electronewb, Jul 8, 2013.

  1. electronewb

    Thread Starter Member

    Apr 24, 2012
    260
    3
    I bought this flashlight a few days ago. Either you can power it from the power supply or you can put "rechargeable batteries" in it. The problem is what kind of batteries!! I called the company and they don't know. And the manual has about 3 lines and doesn't mention the type of rechargeable batteries needed.

    The best results I got so far is with rechargeable Alkaline batteries. I drained them to around .4V and was able to recharge them with the flashlight to 1.1V but at 1.1V that's around %20 less power than with the power supply or non-rechargeable alkaline batteries. How come I cannot recharge them to 1.5V? I've attached some pix (the black strips on the flashlight is just grip tape since the case is very slippery).
     
  2. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    Rechargeable alkaline batteries are a scam. They don't recharge to anywhere near full capacity.


    Use NI-CD or NI-MH. Even though the cell voltage is lower, the light will probably be brighter because lower internal cell impedance (so less wasted voltage drop). You will likely need to add a series resistor to limit current from the wall wart.
     
  3. crutschow

    Expert

    Mar 14, 2008
    12,977
    3,220
    Recharageable alkaline batteries do not like a deep discharge as noted here. The work best if only partially discharged.

    Typically NiMH recharageable batteries are used in flashlights.
     
  4. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    Yeah, I worked at NSC back when they trotted them out around 1994. They wanted us to do some charge IC's pro bono because they would be a "big seller". Took me five seconds to smell the scam. They can only be recharged fully as long as you don't discharge them..... seriously the stupidest product concept I had seen up to that time. They died a quick death in the marketplace but some company has trotted them back out again as a "green" solution. You can always shear the sheep as long as a product has a green leaf on the label.

    here's why the concept of "rechargeable" alkaline is bogus:


    http://batteryuniversity.com/learn/article/will_the_reusable_alkaline_battery_have_a_future
     
  5. electronewb

    Thread Starter Member

    Apr 24, 2012
    260
    3
    Second test I put 3 Enloop batteries I had to look online for what type of batteries they are since it doesn't say on the packages they are NiMh batteries the think is I found them in a drawer and probably haven't use them in over 3 years!!
     
  6. electronewb

    Thread Starter Member

    Apr 24, 2012
    260
    3
    Would that power supply charge any type of batteries?
     
Loading...