Lithium or Not ?

[Henderson,Eric]

Thanks Jim.
-----Original Message-----
From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On Behalf Of JOddino
Sent: Friday, September 05, 2003 12:30 PM
To: discussion at nsrca.org
Subject: Re: Lithium or Not ?


The charger is a very important part of the system. One thing to take note of in Troy's message is the charger has an Ammeter.  The meter tells you a lot about the state of charge and the charging process.  You will get to know that after so many flights the charger will start at so many amps.  You will know that after x minutes the current should drop to y amps.  If it is doing this you can walk away with a reasonable knowledge that everything is working like it should.  When you come back and the current is down to less than 50 mA you can be assured it is charged.  
Of course the very expensive chargers with digital readouts will give you the same info and more will allow the same level of confidence that the charge process is going well.
For example if you used the 3 cell transmitter charger on your 2 cell airborne pack you wouldn't see the current start to fall and you would know something was wrong and you wouldn't walk away without fixing it.
I'm hearing about more and more horror stories and so far I think the chargers have been the culprit.  Anyone got any better info?
Jim

----- Original Message ----- 
From: Henderson,Eric <mailto:Eric.Henderson at gartner.com>  
To: discussion at nsrca.org 
Sent: Thursday, September 04, 2003 1:15 PM
Subject: RE: Lithium or Not ?

I would add that we get focussed on the battery and not the charger. All batteries will do something nasty if seriously overcharged.
 
I pay a lot of attention to what Jim O. tells me. If the charger will not prevent an overcharge then you have high risk situation. Jim has written about this before.
 
Regards,
 
Eric.
 
 
-----Original Message-----
From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On Behalf Of Troy Newman
Sent: Sunday, August 31, 2003 6:49 PM
To: discussion at nsrca.org
Subject: Re: Lithium or Not ?


Li-ion packs.
 
Bob, and Lance.....
I have been running these 2000mah packs since February. They are a 2 cell pack. Central sells them for $35 a pack and they have a $50 charger....Here is the kicker. The charger is plug in and forget. It can't harm the batteries even if left on charge for 3 months. Its basically a voltage regulator setup where it puts out 8.4V and when the pack reaches 8.4V its done....The nice thing is the charger has a Amp meter on it so when the battery is empty it might take 1-1.3amps but as it charges the current flow goes to zero. Once the pack is charged up the current flow is zero and no juice is going to the battery. You're not waiting for a light to turn color or go out...You can see what is actually going into the battery.
 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.f3a.us/pipermail/nsrca-discussion/attachments/20030905/a6e04fae/attachment.html