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Fast charging a Futaba 8FG?

Old 06-03-2011, 06:58 PM
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green river rc
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Default Fast charging a Futaba 8FG?

Can I safely fast charge my 8FG. What's so "special" about the supplied wall wart charger?
Old 06-03-2011, 07:45 PM
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Charlie P.
 
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Default RE: Fast charging a Futaba 8FG?

Yes you can.  Nothing special about the stock charger except that it is a little beefier (170 mAh & 150 mAh) than the older Futaba 100 mAh & 70 mAh wall warts.
Old 06-04-2011, 07:32 AM
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Zor
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Default RE: Fast charging a Futaba 8FG?


Addressed to all readers,

Some facts and figures concerning a wall charger supplied with a Spektrum DX7.

Markings on the charger ____
Input 120V 60 Hz 5 VA
Output TX DC 11.6 V 110 ma
Output RX DC 5.8 V 110 ma

I measured my line voltage at 127 V AC (We have 60 Hz here).
I read the shorted output of TX at 300 ma.
I read the shorted output of RX at 242 ma.

Note that the output voltage quoted on the charger for both TX and RX is just about the maximum voltage expected from the fully charged battery packs.

What ever the amount of charge in the batteries when they are being connected to the charger will deliver some charging current that is unknown unless measured (we do not know the amount of charge already in the batteries) .

That current will not be 110 ma.

As the charge is going on the charging current will keep diminishing as the battery packs increase in voltage. That charging current will become very small as the battery packs reach full charge.
This also explain that we can leave the battery packs on charge all night and will not damage the batteries.

I hope this post is helpfull to some reader(s).
These chargers are the least expensive and the most convenient for not damaging our battery packs.

Zor
Old 06-04-2011, 09:22 AM
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Zor
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Default RE: Fast charging a Futaba 8FG?


ORIGINAL: green river rc

Can I safely fast charge my 8FG. What's so "special" about the supplied wall wart charger?
green river rc,

Yes you can ___if you are careful about over-charging which may damagw the battery pack(s).

A voltage measurement with a known accurate voltmeter while charging is not an indication of a fully charged battery.

The output current shown on a charger is not the charging current.
It is a rating not to be exceeded from the charger on a long run.

I would not say there is anything "special" about a wall wart charger.
Its advantage is that its maximum output voltage is the typical voltage of a fully charged battery pack and using it for a long time charge ends up with a known fully charged pack.

The obvious reason why these chargers are supplied with a new Tx and Rx.

Zor

Edited 05 June 2011 at about 15:30 EDT to change "lont" to "long".

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