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Old Jan 04, 2003, 07:42 PM
Registered User
Thousand Oaks, California, USA
Joined Jan 2003
15 Posts
First post... totally confused about charging!

I've searched the archives, and read many posts... but I still can't figure out this whole battery/charging system!

I've got a new Zagi-X with the KR-1700AU battery (I've got two of them). My charger is a PF-12 Park Flyer plugged into an A/C outlet (charge at home - fly at the field).

I charged the first battery at 800 mA for 90 minutes. I charged the second battery at 1200 mA for 90 minutes. Which is correct? Should I charge them both at 1700 mA? I want long battery life, and good run times.

Also, should I completely drain the batteries before re-charging (hook them up to a small bulb and let them drain)? Would this help?

Thanks in advance!
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Old Jan 04, 2003, 07:52 PM
Senior Moment Member
Virginia Beach, Va.
Joined Jan 2002
1,233 Posts
Welcome to the EZone!! Confused? You'll fit right in here.

Yep, charge them at 1700 mA. That's called 1/C, or 1 times the cell capacity.

They usually perform better after a few charges.

No need to discharge them down, just charge, fly, charge, fly.....

Have fun..............


Jimmy
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Old Jan 04, 2003, 08:33 PM
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Hi Jimmy, let's not mislead the new chap. You said it right: "1 times cell capacity" but 1/C means 1 divided by cell capacity. It should be 1C.

Regards,

Hank
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Old Jan 04, 2003, 09:16 PM
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Thousand Oaks, California, USA
Joined Jan 2003
15 Posts
OK. Thanks for the quick replies.

In idiot/novice/layman terms that means turn the dial to 1700 mA and push the start button? So, my unit will charge for 90 minutes, then trickle (1/10) for another 90 minutes. Do I need to pull the battery after 60 minutes?

What if I want to plug it in and walk away? My guess would say ~1200 mA @ 90 minutes is the same as 1700 mA @ 60 minutes.

Sorry for another lame follow-up question.

(BTW - I flew gas models about 15 years ago then put them in storage one day - never to fly them again. About two months ago, I saw some guy flying a Zagi at a park. It was quiet, clean, and he was not at an 'airfield' for RC. I was blown away at how far electric planes have come! I asked for one for X-Mas (and Santa delivered). It flew for the first time on Wednesday, and it's not going away anytime soon.)
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Old Jan 04, 2003, 11:24 PM
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We'd need to know what your charger can do. Who makes/sells the unit you have. Is it a peak charger? Is the charge current selectable? etc.

Hank
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Old Jan 05, 2003, 12:29 AM
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Thousand Oaks, California, USA
Joined Jan 2003
15 Posts
It is a PF-12 Park Flyer AC/DC Peak Charger by WattAge
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Old Jan 05, 2003, 12:49 AM
Registered User
Pittsburgh, PA
Joined Jan 2002
1,271 Posts
You seem to have the basics done OK (you've said: ~1200maH x 90 min same as 1700mah x 60 min? and pull after 1 hour?). Just have a little confidence You shouldn'y need any trickle charges, be careful to not leave them totally unattended, and notice how hot they get (heat shortens batt life).
Go for it
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Old Jan 05, 2003, 01:01 AM
soft yummy goodness.
freq's Avatar
North Jersey, USA
Joined Oct 2001
735 Posts
Welcome to Ezone! For an excellent primer on charging and things related, see the following:

www.rcbatteryclinic.com/

- chris
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Old Jan 05, 2003, 06:29 AM
Senior Moment Member
Virginia Beach, Va.
Joined Jan 2002
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You're right Hank, that was a critical typo. But at least I didn't type 1700 amps for a charge rate.

Jimmy
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Old Jan 07, 2003, 03:01 PM
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washington state
Joined Dec 2002
185 Posts
Just my $.02 worth.

I was always led to believe that any new pack
should be slow charged the first time, and a new pack just soldered togather MUST be slow charged to equalize
the cells. Also a pack that has been fast charged a few times
should be slow charged once in a while.

Now a question. Does this hold true for the new current
state-of-the-art batteries being sold today ?

I'm new to park / slow flying, but I started flying electric
around 1994. Electric-Cub, PT-Electra, Electra Streak,
Spectra Glider. If you think 6 or 7 AA cells are heavy
try 12 sub-c cells. A lot of the cells I fly with today I started
out with in 1994.

This is great group you have here, your never to old to learn
something new (and I know cause I'm old) somedays anyway.

OldMan
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Old Jan 07, 2003, 07:43 PM
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Virginia Beach, Va.
Joined Jan 2002
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oldman,

You're absolutely right, it's pretty well established practice to give them that initial first slow charge. And again from time to time just to keep the entire team pulling together. I just failed to mention it.

See, told you I was pretty confused.

Jimmy
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Old Jan 08, 2003, 10:48 AM
Space Coast USA
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Space Coast
Joined Oct 2000
21,019 Posts
1. Slow charge all new packs at 0.1C for 16 hrs. Use as is.
2. After initial slow charge and a normal discharge cycle, charge at 1C.

C= cell capacity in mah/1000

C = 1700mah battery/1000 = 1.7A

Set charger to deliver 1.7A

A fully discharged battery will take about 1 hr to charge.

hoppy
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