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Old May 14, 2011, 09:05 AM
Air, Ground & Water
freechip's Avatar
Canada, ON, Rockland
Joined Aug 2008
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Its been said before that the charge rate is the same and so it would take almost forever to charge the lipo.

I gave up after several hours charging mine and simply put in on my regular charger. The amount of time its going to need to be recharged I don't mind doing it this way BUT the mod above is looking interesting.

Looks almost factory built.
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Old May 14, 2011, 09:05 AM
Silicon/poker/chocolate chips
Chip Geek's Avatar
Austin, TX
Joined Sep 2008
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Quote:
Originally Posted by cayars View Post
Does it charge Lipos at a faster rate then NiMH or at the same rate?
Post 6130 says same rate, 200mA.
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Old May 14, 2011, 09:09 AM
AndyKunz's Avatar
Illinois
Joined Sep 2001
22,367 Posts
Quote:
Originally Posted by cayars View Post
Does it charge Lipos at a faster rate then NiMH or at the same rate?
200mA max.

With a LiPo charger (pretty much ANY good LiPo charger), the start of charge is current-limited to a max value. We use 200mA for ours. Once the current draw drops below that limit, the charger goes into constant-voltage mode (8.4V for 2S) and remains there until fully charged. In this mode, the current drops slowly to 0.

It's because of this slow dropping to 0 that the LiPo mode is charging for a longer time. You don't need to wait until the light goes out, as this long duration is only putting the last few percent into the pack.

Andy
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Old May 14, 2011, 10:50 AM
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cayars's Avatar
Bridgeton, NJ
Joined Mar 2009
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Anyone find a good 2 cell Lipo battery that fits the transmitter well? Wouldn't mind having a couple of them.
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Old May 14, 2011, 10:55 AM
Air, Ground & Water
freechip's Avatar
Canada, ON, Rockland
Joined Aug 2008
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Quote:
Originally Posted by cayars View Post
Anyone find a good 2 cell Lipo battery that fits the transmitter well? ....
You mean OTHER then this one? http://www.horizonhobby.com/Products...D=SPMB4000LPTX
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Old May 14, 2011, 10:57 AM
AndyKunz's Avatar
Illinois
Joined Sep 2001
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Originally Posted by cayars View Post
Anyone find a good 2 cell Lipo battery that fits the transmitter well? Wouldn't mind having a couple of them.
Don't go just by fit!

Our battery pack includes safety and balancing circuitry inside it. It's not just a 2S LiPo!

Andy
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Old May 14, 2011, 11:18 AM
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akschu's Avatar
USA, AK, Houston
Joined Aug 2005
789 Posts
Quote:
Originally Posted by AndyKunz View Post
Schu,

Sorry you don't like our built-in charger. It's not about to change.

The charger takes 12V bulk power, unregulated, and provides a 200mA max charge rate (which is a 1/10 C trickler for the stock 2000mAh NiMH pack). What you're asking for is not a charger; you need a direct connection to the cells, and you came up with a solution that meets your needs. I have to compliment you on your resourcefulness. You did a nice, clean modification.

Andy
Andy,

I am also an engineer for a living so I can usually come up with a decent solution to problems like this.

Anyway, what I'm asking for is either a direct connection *or* a charger that doesn't suck. The built in charger is a decent enough idea, and I would even tolerate the insanely slow charge rate, but I won't charge a battery inside of a device without peak detection nor will I trust my aircraft to a battery that is routinely abused.

Anyway, you didn't answer my first question, are there changes to later run DX8s that address the issues with dsm2 RXs? I have a AR6200 in a $1500 airplane that has been dead reliable with my X9303, now I have the DX8 and I want to trust it. Not because I hope it will work, or nothing bad has happened yet, but because of engineering fact that there was a problem, and it has been fixed.

Thanks,
schu
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Old May 14, 2011, 11:19 AM
Air, Ground & Water
freechip's Avatar
Canada, ON, Rockland
Joined Aug 2008
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Its a safe, balancing 4000mah 2s Lipo that last so long I lost count.
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Last edited by freechip; May 14, 2011 at 11:41 AM.
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Old May 14, 2011, 11:23 AM
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akschu's Avatar
USA, AK, Houston
Joined Aug 2005
789 Posts
Huh? I'm not picking up what you are laying down.
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Old May 14, 2011, 11:26 AM
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akschu's Avatar
USA, AK, Houston
Joined Aug 2005
789 Posts
For those that don't want to use a lipo in their TX (I'm one of them) nor do they want to modify the radio like I did, here is a workable solution:

Charge the battery for 8 hours or so (I wouldn't do the full 10) then get a outlet timer deal for christmas lights or whatever and set it to run for 30 minutes a day. Leave the tx plugged into the charger.

It will keep the batteries topped off with minimal abuse so your tx will always be ready to go.

schu
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Old May 14, 2011, 11:31 AM
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Harry H's Avatar
Los Angeles
Joined Oct 2010
1,518 Posts
Quote:
Originally Posted by akschu View Post
For those that don't want to use a lipo in their TX (I'm one of them) nor do they want to modify the radio like I did, here is a workable solution:

Charge the battery for 8 hours or so (I wouldn't do the full 10) then get a outlet timer deal for christmas lights or whatever and set it to run for 30 minutes a day. Leave the tx plugged into the charger.

It will keep the batteries topped off with minimal abuse so your tx will always be ready to go.

schu
That's what I have been doing. Works fine but it would be nice if the "worlds most advanced 8 ch radio" had a better internal charger that would shut off. Or, just have the lipo standard.

Harry
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Old May 14, 2011, 12:40 PM
Registered User
Dallas, TX
Joined Jan 2010
753 Posts
Quote:
Originally Posted by cayars View Post
Does it charge Lipos at a faster rate then NiMH or at the same rate?
Here you go ...

Quote:
Originally Posted by AndyKunz View Post
Still 200mA max. The first time I charged my DX8 pack it was 40 hours before the light went out. I've charged that radio 3 times now.

Andy
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Old May 14, 2011, 01:14 PM
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Joined Jan 2011
745 Posts
I simply can find no fault with the stock 2000ma NIMH setup - I have one DX8 using ENELOOPs (latest permutation) and the other using std cells - either will fly an entire weekend -
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Old May 14, 2011, 01:31 PM
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Vienna, Austria
Joined Oct 2010
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Quote:
Originally Posted by akschu View Post
Anyway, you didn't answer my first question, are there changes to later run DX8s that address the issues with dsm2 RXs? I have a AR6200 in a $1500 airplane that has been dead reliable with my X9303, now I have the DX8 and I want to trust it. Not because I hope it will work, or nothing bad has happened yet, but because of engineering fact that there was a problem, and it has been fixed.

Thanks,
schu
Dont fly it with your DX8. It seems that Spektrum is on the "don't say anything" policy on this issue. I exchanged all my heli RXs with DSM-X RXs so I can fly without worrying. Either Spektrum solves this issue or they have to exchange my DSM2 RXs with DSMX-ones.
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Old May 14, 2011, 02:51 PM
AndyKunz's Avatar
Illinois
Joined Sep 2001
22,367 Posts
Quote:
Originally Posted by akschu View Post
Anyway, you didn't answer my first question, are there changes to later run DX8s that address the issues with dsm2 RXs?
The only differences between the batches at the factory that I have any knowledge of are that they are shipping with 2.01. The only reason I know that is because I prepared the files. I'm not very close to the production side of things, so asking a question about a production thing in a totally separate area (RF) is way outside my sandbox.

Andy
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