Some battery charging consideration

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    • February 5, 2003 at 2:36 am #10863
      Efarel
      Participant
      • Posts: 76

      Hi,

      last night I built a simple stand off charger with 4 AA batteries and the clip from a spare controller.
      I’m not a big fun of the battery2battery charging but I had no time to build a proper charger (it will be my next project !).
      By the way, I charged a car for 5 minutes and the battery inside (standard 60mah) was not even warm.
      The car sprinted on my circuit for a very looong time, I had 28 minutes of driving time !!
      28 minutes of driving time, ie no slow car ranting on the straight but good old driving time !! After 25 minutes of speeding I was tired and a sort of nausea was coming up !! Too much time !
      Tonight I’ll charge it for 3 minutes and I expect 15 minutes of driving time.
      A note… with the antenna mod http://www.geocities.com/bitcharitaly/micro_topi_modificati.jpg and the more serious charging I can control better, a lot better, my little car. It is more responsive in steering and the reaction time was minimized.
      I’m now going to build a simple no timer NiCd charger with a LM317 as regulator. Stay tuned !
      Efarel

    • February 5, 2003 at 5:10 am #41708
      z-beam
      Participant
      • Posts: 2265

      it will work man but dont expect your bats to last long. pick up some NiMh cells ( 1/3 aaa) for your bit, theyre rated at 120mah

    • February 5, 2003 at 7:06 am #41709
      Efarel
      Participant
      • Posts: 76

      hmmm
      imho i tink that a better charging/decharging routine is better for the battery.

      Ok, we are ultra rapid charging those little battery at 45 seconds so we’ll charge/decharge it more time then with a single longer charge.
      Less frequent but longer charging cicles will preserve the battery more than a lot of 45 sec charging.
      Btw how many minutes do you drive with a standard battery and a standard 45sec charge ?

      Efarel

    • February 5, 2003 at 3:00 pm #41695
      PandaBear
      Participant
      • Posts: 1866

      How cold is your surrounding ambient temperature?

      imho The battery is probably too small to retain much heat, you’ll not be able to notice much heating effect. Tiny batteries also have more surface area vs volume compared to a larger cell, so has better heat transfer.

      If its overcharged it’ll just vent its electrolyte silently and doubt you’ll see any trace of that.

    • February 6, 2003 at 5:35 pm #41670
      ph2t
      Participant
      • Posts: 2088

      hey efarel, that charger idea using an LM317 is great! I take it you are going to use it in constant current mode. Couple this with a 555 timer circuit and you will have a pretty could charger. You could then mod it for selectable voltages (for all the dual, triple cell mods out there…..).

      keep up the good work!

      ph2t.

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