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Old Apr 04, 2012, 02:35 PM
Stop scaring my donkey!
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Quote:
Originally Posted by Gerry__ View Post
Peak detection uses voltage. That's what the 'peak' is, a peak in voltage. Really, manually changing the DX8 is very easy.

But if you are saying you are unable to gauge the amount of time you should charge the DX8 for based on the voltage, then you need to change to another Tx, this one is too advanced for you.
Gerry, you've hit the nail on the head!

Now, if that guy would just stop chasing me I'd get my DX-8 fully charged! (I don't think I really like Florida.)

Everything was so simple when I was a kid: we walked 10 miles to school, in the snow, rain, and mud, and it was uphill both ways.
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Old Apr 04, 2012, 02:38 PM
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It's not quite dead yet!

Monty Python-Bring out your dead! (1 min 55 sec)
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Old Apr 04, 2012, 02:41 PM
Stop scaring my donkey!
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Fetchez la vache!

http://www.youtube.com/watch?v=7FJVAcvVcPQ
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Old Apr 04, 2012, 02:46 PM
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Originally Posted by Gerry__ View Post
But if you are saying you are unable to gauge the amount of time you should charge the DX8 for based on the voltage
Well, that is the rub...YOU CAN'T. If the battery indicator reads 4.8v (0.3V) , the battery may be at 80% or 20%. There is no way to know, thus you have no idea how long it will take to fully charge the battery.
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Old Apr 04, 2012, 02:55 PM
Bye Bye VP Aug 2010 - Aug 2012
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Originally Posted by grumpy42 View Post
Well, that is the rub...YOU CAN'T. If the battery indicator reads 4.8v, the battery may be at 80% or 20%. There is no way to know, thus you have no idea how long it will take to fully charge the battery.
You don't look at the battery indicator then? In truth the discharge curve isn't as flat as you say it is. The Tx battery indicator uses voltage to gauge capacity and is accurate enough for the user to work out how long to put it on charge.

It really is very simple, but maybe you should change to another brand?
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Old Apr 04, 2012, 03:03 PM
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It's quiet scary that there are some people on here that have little knowledge of how different chemistry of batteries truly work, but then again they do say a little knowledge can be dangerous!
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Old Apr 04, 2012, 03:06 PM
Bye Bye VP Aug 2010 - Aug 2012
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Originally Posted by topgearuk View Post
It's quiet scary that there are some people on here that have little knowledge of how different chemistry of batteries truly work, but then again they do say a little knowledge can be dangerous!
What these people are saying is that they want to plug in and forget. Better stay away from lipo technology then!
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Old Apr 04, 2012, 03:08 PM
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You don't look at the battery indicator then? In truth the discharge curve isn't as flat as you say it is. The Tx battery indicator uses voltage to gauge capacity and is accurate enough for the user to work out how long to put it on charge.
Wrong. The battery indicator just tells you the voltage of the battery. It gives virtually no indication of "intermediate" charge state. The NiMH discharge curve is rather flat and it will remain at the same voltage (as displayed on the DX8) for 80% of the time.

You simply cannot tell how long to charge the DX8 base solely on the displayed voltage (unless the battery is either charged or depleted).
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Old Apr 04, 2012, 03:14 PM
Bye Bye VP Aug 2010 - Aug 2012
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Originally Posted by grumpy42 View Post
Wrong. The battery indicator just tells you the voltage of the battery. It gives virtually no indication of "intermediate" charge state. The NiMH discharge curve is rather flat and it will remain at the same voltage (as displayed on the DX8) for 80% of the time.

You simply cannot tell how long to charge the DX8 base solely on the displayed voltage (unless the battery is either charged or depleted).
On my DX8, the voltage and battery indicator goes down with use, it is not a flat curve.
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Old Apr 04, 2012, 03:17 PM
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Now that IS funny!

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Originally Posted by topgearuk View Post
It's not quite dead yet!

And that...

http://www.youtube.com/watch?v=grbSQ6O6kbs
And that...

Quote:
Originally Posted by JohnathanSwift View Post
And that too!

Quote:
Originally Posted by Gerry__ View Post
What these people are saying is that they want to plug in and forget. Better stay away from lipo technology then!
+1000

I read the manual when I got my DX8 and amazingly... no problems with charging the battery. But I have to give full disclosure and make a confession.

I monitor my batteries when charging - method, interval and intensity depends on battery type.


JC
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Old Apr 04, 2012, 03:19 PM
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Originally Posted by grumpy42 View Post
You simply cannot tell how long to charge the DX8 base solely on the displayed voltage (unless the battery is either charged or depleted).
I missed where it is supposed to do that.

Therefore the manual and design must be defective.

JC
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Old Apr 04, 2012, 03:24 PM
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Quote:
Originally Posted by Gerry__ View Post
On my DX8, the voltage and battery indicator goes down with use,
You do know that the "battery indicator" is just a graphical representation of the voltage and not an indication of capacity.

Quote:
Originally Posted by Gerry__ View Post
it is not a flat curve.


It is mostly flat for about 80% of the time. As the battery nears depletion, the voltage will fall off rather quickly. When the battery is freshly charged, the voltage will fall off rather quickly and then remain at around the same voltage for most of the time.

Quote:
Originally Posted by JC Spohr View Post
I missed where it is supposed to do that.

Therefore the manual and design must be defective.

JC
My comment was referring to Gerry's erroneous assertion. It was not an attack on the DX8.
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Old Apr 04, 2012, 03:25 PM
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+1000.
So, then, by implication, you agree that an Aurora 9, a JR X9303 or whatever can also get hosed by the user.

School must be out, eh?[/QUOTE]

Don't know about JR, never owned one, although my dad has and they are good radios as far as his experience.

An A9 can be left overnight(and then some) on the supplied wall charger. Done it many times. It charges at less than 1/10 C (80 mA charge for a 1300 mA battery).
The charger light goes dim/out when its done.

Simple process for a simpleton like ME! LOL.

I've never heard of any A9 users smoking their battery pack with the stock charger(although I'm sure there are some), but there are plenty of cases with the DX8. In some cases it doesn't just destroy the battery but melts/burns the radio case as well. For a company so concerned about liability in this litigious society, thats a little contradiction.
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Old Apr 04, 2012, 03:35 PM
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To add a little bit:
The DX8 uses vey little current - so - the readout is fine for it's purpose IF used as intended
also and this has to do with NIMH-
The present generation, needs to "form" -call it breaking in if you will-
use low current stock setup is fine - and first time around - IF the batt read say 4.8 - check it at about 5 hours -then at the recommended 12.
It will get a bit warm NOT hot!!!!
afer it is down again to say 4.6- recharge for 12 hrs- -it again should be a bit warm
The meter on the tx will likely read a bit higher second time around
Beause the amp demand is low the absolute state of charge vs voltage read is not worth worrying about .
If it were a A123 battery - different ballgame - those are really flat curve types and require a different approach.
If you are a long time user of nimh in old PCM radios - the Dx8 setup will seem strange as those old types needed charging for every flying session.
In this case - the drain (power used) is far lower and the batteries are better and have typically more capacity An old X347 had a 600 ma pack!
As for the horror stories - I guess some guys can bust an anvil with a rubber mallet . Seen this over n over ---
There are quite a few DX8's here - only one had a "hot battery problem and he was charging it after every flying session, even tho it may have had one flight - a quick review - and all was well.
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Old Apr 04, 2012, 03:35 PM
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Quote:
Originally Posted by Gerry__ View Post
What these people are saying is that they want to plug in and forget. Better stay away from lipo technology then!
Thats what EVERY rational person wants. Its available with other transmitters.

If a company invented a battery technology that could be "set and forget"(without fear of fire or ruin) on a charger and had the same energy density(and price point) of Lipos, don't you think EVERYONE would jump on the bandwagon? Of course they would.

All except you Gerry. You're content with your 1970's charger and gas pumps that don't shut off by themselves! LOL. Get real.

Actually, my 1970's Kraft sets could be left on their chargers almost indefinately, so that was a bad example.
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