Li-ion chargers

[Troy Newman]

Yep been using the NMP Charger and Batts since Feb 03. They are great. The
Charger can't over charge the batts as the voltage reaches the 8.4V limit
and no current flows. Piece of cake. Dummy proof. I love the batteries as
they are light and carry great power. I was getting 8-10 flights on a charge
and they charge up in about 3hrs....In fact I rarely charge over a weekend
of flying. No need...I put 6-7 flights on a model in the weekend and its
still got room for 3-4 more flights. Makes practice nice also...I can fly
back to back as many as I want in a day....

There were times this spring I was flying 8 flights per model in a day with
2 different models. Batteries were a no brainer!

Another nice thing they are very predictable. I can tell when my servo pots
start to get worn...the plane uses more volts per flight.....I'm drawing
about 185-200ma per flight...that is a full 13-14mins on a DZ usually a P
and an F sequence. Hydemount, DZ, all JR digitals....it takes about 0.10
volts per flight....Starts at 8.4V and after 3-4 flights it hits 8V then 3-4
more it hits 7.6 then 3-4 more it hits 7.2.....I'm using just a 500ma load
and a digital volt meter.....I stop flying down just below 7.2V

I have a motor mount problem this year...came loose...I noticed something
wrong on my battery drain...started looking for a problem and wham there it
was....I fixed it and my drain went back to normal.

This comes with spending lots of time with your model and knowing how it
functions and how it reacts to all kinds of different situations.

TN

----- Original Message ----- 
From: "Henderson,Eric" <Eric.Henderson at gartner.com>
To: <discussion at nsrca.org>
Sent: Wednesday, November 19, 2003 12:02 AM
Subject: Li-ion chargers


Although I am very happy with my cigar-lighter type chargers for my 2000 mAh
2-cell Li-ons, I need some reassurance that they were all working the same.

I purchased an NMP charger from Central Hobbies, (Jim Oddino is the designer
I think). It has an nice analog meter that goes down to zero when the pack
is fully charged.

I took some fully charged Li-ion packs, from different chargers, and tried
to charge them with the NMP. What I saw was that the NMP charger shows a
small amount of charge still goes in, then it goes to zero showing a fully
charged pack. Only for about a minute. I concluded that the car chargers
were doing just fine.

LED's work just fine but you can't beat a good old meter when you want to
know.

Regards,

Eric.

Paid up member of ARA - Anal Retentives Anonymous :-)
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