[Elecraft] OT Battery question

[Don Brown]

Hi

All fast chargers will cause the batteries to get quite warm, but not so hot that it is uncomfortable to touch the batteries. There are some chargers that overdo it. The so called 1 hour chargers are the ones that are the problem. This is just a little too fast for a AA cell. I have tried a lot of chargers but the Maha 401 is the best I have found for AA and AAA cells. This charger has slots for 4 cells AA or AAA in any combination. Each slot is independent so the charge is monitored on each cell rather than several in series. It has a fast mode that will charge a set of 2000 mA hr cells in about 100 minutes or a slow mode that will charge them in about 4-5 hours. When the charge is complete the charger switches to a trickle mode of 50 ma per cell to top them off. This charger seems to put the most power back into the batteries without overheating the batteries. It uses a delta V pulsed charging algorithm. It cost about $35 and comes with a set of 2000 ma batteries or you can buy it alone for about $25. There is also a 12 volt cable for the car.

For larger battery packs the best I have found is the Maha 777+ This charger will handle battery packs of just about any size or any voltage up to about 16 volts automatically. It has an innovative connector that allows it to connect to just about any configuration on the pack and it will determine the proper charge voltage and polarity. It can cycle a pack and will display the mA Hr input to the battery on a digital display. It will also charge LiOn type batteries as well as NiCad and NiMh batteries.

Don Brown


  ----- Original Message ----- 
  From: Vic Rosenthal<mailto:vic at rakefet.com> 
  To: Elecraft<mailto:elecraft at mailman.qth.net> 
  Sent: Thursday, May 20, 2004 4:53 PM
  Subject: [Elecraft] OT Battery question


  I have a battery charger for NIMH aa cells.  I charge NIMH aa cells in 
  it, as you are supposed to do.  The cells get very hot (too hot to touch 
  for more than a few seconds) when charging, and the charging process 
  takes only a few minutes.

  My feeling is: this can't be good.  Should I look for a slower, more 
  gentle, charger (recommendations?)  Or is this the way NIMH cells are 
  supposed to work?

  -- 
  73,
  Vic, K2VCO
  Fresno CA
  http://www.qsl.net/k2vco<http://www.qsl.net/k2vco>


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