[NSRCA-discussion] Changing list behavior. Chargers..?

[Rex LESHER]

Del
I am assuming you are talking Lipos here....   I would have to say no, not really.   I've studied a lot of chargers and came to the conclusion that there is a lot available out there, but are mostly site specific.  The best combination for automatic and safety I've come across so far is the TP 1010c / TP 210V, charger/balancer combo.  If used in tandem during a charge, the charger listens to the data presented by the balancer and charges according prescribed parameters.  If there is anything that gets outside the parameter limits, the charger will shut down and issue an error code for you to read.  It will not charge any more until the error is dealt with. 
This also means that you have to be there to do something to correct the problem.  For instance, if your 5s 4p battery pack is nearly at full charge and you want to top it off, you just plug it in to the charger, along with the balancer, and set the cell count/ charge rate, and press start.  What happens, is the charger will start the initial charge, read the battery voltage and stop the charge.  It issues an error saying wrong cell count.  It wants to make sure you set the cell count correctly in the first place.  You read the error, say something about the "stupid thing" and just press start again.  The charger now knows that you knew what you were doing and starts charging, but reduces the charge rate automatically and continues to do so until the charge is completed.
Pretty simple, but you still have to be there to make sure it all goes according to plan.  The other problem is with cell balancing.  Sometimes during a charge, a balancer will give an over voltage error on one or more cells and stop the charge.  You have to either lower the charge rate or let the balancer bleed the high cell(s), then continue the charge.  
I believe that the safest way to charge is when you have the balancer active during charge.  If a cell becomes over charged during the process, and the charge continues, the cell is damaged at the very least.   Once the cell is damaged, anything could happen, including fire.  Without a balancer connected during charge, and the ability of the balancer to feed info to the charger, the charger has no way of knowing what individual cells are doing.  
I've seen lots of adertisements that leads you to believe that the item is the neatest thing since sliced bread.  You have to realize that to make money in marketing these days, you have to get in on the ground floor.  This is part of the problem.  Suppliers sometimes don't know really any more than the people using the product.  One such advertisement I read said that the charger will reduce the charge rate in heat generated in direct sunlight.  Gee, that's great, except for one thing, if you want to see a really nice explosion, just charge your big Lipo out there in direct sunlight at 100 degrees.  The battery pack will get so hot, you couldn't even pick it up.  You don't want to let your Lipos get over 150 degrees.  Anything higher than 170, and look out for the impending burst...  
I am sorry to say that we have to seperate the wheat from the chaf...  You have to know what you need and why.  This will all get easier as time goes on.  There's a lot guys out there now, using and testing many different configurations of electric flight products.
As the season goes on, we'll see an abundance of information presented.  It's still early in the game.
I hope this helped....

Rex Lesher

  ----- Original Message ----- 
  From: Del K. Rykert<mailto:drykert2 at rochester.rr.com> 
  To: NSRCA Mailing List<mailto:nsrca-discussion at lists.nsrca.org> 
  Sent: Monday, March 27, 2006 10:42 AM
  Subject: Re: [NSRCA-discussion] Changing list behavior. Chargers..?


  I am going to ask something stupid to some but..  Is there a charger out 
  there yet that lets you plug into your pack and forget about them? It can 
  read the charge of the pack and how much charge it needs to bring it back to 
  full charge..  Only adjustment parameter being how fast you want them to get 
  to full charge?

  ----- Original Message ----- 
  From: "Joe Lachowski" <jlachow at hotmail.com<mailto:jlachow at hotmail.com>>
  To: <nsrca-discussion at lists.nsrca.org<mailto:nsrca-discussion at lists.nsrca.org>>
  Sent: Monday, March 27, 2006 11:01 AM
  Subject: Re: [NSRCA-discussion] Changing list behavior.


  > Jim you forgot the only pain in the butt<G>"Babysitting the batteries 
  > while
  > they are being charged when you get home for the next day"
  >
  >

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