quick question lipo or nimh for a transmitter?

nickypoo · 07-31-2012, 04:27 PM

about to head to the hobby shop....

should i get a stock 9.6v nimh (i think 9.6) or a 3 cell transmitter lipo?

will the higher voltage damage my dx7? i just got it brand new from my boss. its an old dx7 but i got it new in the box never used

Dajavu*Xion · 07-31-2012, 04:58 PM

Good question and i look forward to the responces..All i know is that i have run both and only change i can tell is that the lipo last a heck of alot longer bettween charge ups.

Maypole · 07-31-2012, 05:14 PM

I've run both on my DX8 and prefer the lipos. By a large margin. Longer between charges as mentioned and surplus power for the vibe/tone timer alert I use.

tukkus · 07-31-2012, 06:35 PM

If the DX7 isnt made for lipos you can buy a Tx lipo pack and solder 2 diodes together on the battery so the Tx will only see 11.2v fully charged.

I have been doing that for over a year on my JR 9303 2.4 Tx with no problems. You have to take the battery pack out to charge but that is a minor inconvience.

The packs are pretty cheap, roughly $20-25 and the best part for me is that they charge quickly.

hANDYman · 07-31-2012, 07:29 PM

Quote:

Originally Posted by Blueram

Good question and i look forward to the responces..All i know is that i have run both and only change i can tell is that the lipo last a heck of alot longer bettween charge ups.

Quote:

Originally Posted by Maypole

I've run both on my DX8 and prefer the lipos. By a large margin. Longer between charges as mentioned and surplus power for the vibe/tone timer alert I use.

I've been wondering about LiPo's in a TX also... I just got a DX8 which can take a LiPo. So what am I missing here? A LiPo will last longer in the TX between charges, but I thought that you weren't supposed to leave LiPo's charged. It's supposed to be bad for them. What am I missing?

tukkus · 07-31-2012, 08:25 PM

Quote:

Originally Posted by hANDYman

I've been wondering about LiPo's in a TX also... I just got a DX8 which can take a LiPo. So what am I missing here? A LiPo will last longer in the TX between charges, but I thought that you weren't supposed to leave LiPo's charged. It's supposed to be bad for them. What am I missing?

To get a long life out of your lipos the best option is to always keep them at storage voltage but you'll still get years of use out of them by using them like you would normally do in a TX.

pinguin · 07-31-2012, 09:06 PM

If your Tx use 9.6v NiCad battery, you can use LiFe battery. The voltage close to 9.6v NiCad batt.

desertstalker · 07-31-2012, 09:14 PM

Quote:

Originally Posted by hANDYman

but I thought that you weren't supposed to leave LiPo's charged. It's supposed to be bad for them. What am I missing?

2 things:
Leaving a LiPo charged increases its internal resistance, this is bad when you are trying to suck 50A from it, not an issue when you only need 100mA.
LiPo's designed for low discharge rates (TXs phones laptops etc.) are damaged much more slowly by being kept full, compared to the high-C LiPos used for flight packs. So the damage will be slower.

You will get several years out of a TX LiPo, or longer, especially if you dont mind that it only holds half what it did when new (for the DX8 that would put it around the same place as the stock NiMH pack at ~2Ah).

hANDYman · 07-31-2012, 09:42 PM

Cool... good info, thanks guys. I may have to look into getting one.

TheBum · 07-31-2012, 10:29 PM

I use Eneloop NiMH packs in my DX7 and X9303. You can use the stock charger and they hold their charge a lot (months) longer than regular NiMH.

RCTada · 07-31-2012, 10:41 PM

Quote:

Originally Posted by TheBum

I use Eneloop NiMH packs in my DX7 and X9303. You can use the stock charger and they hold their charge a lot (months) longer than regular NiMH.

I use eneloops as well for my DX7SE. All 8 of em!

Sent from my DROID BIONIC using Tapatalk 2

backburner1955 · 07-31-2012, 11:58 PM

Quote:

Originally Posted by pinguin

If your Tx use 9.6v NiCad battery, you can use LiFe battery. The voltage close to 9.6v NiCad batt.

I use a Hyperion 3S LiFe Pack and get 4x the life per charge as the NiMh pack that came with it, plus no modifications to avoid overvoltage damage.

TheBum · 08-01-2012, 12:07 AM

Quote:

Originally Posted by backburner1955

I use a Hyperion 3S LiFe Pack and get 4x the life per charge as the NiMh pack that came with it, plus no modifications to avoid overvoltage damage.

Are you saying you can actually use the stock charger? I tried to do that, believing Hyperion's claim that it was safe, and I ended up with two puffed packs: the one I bought and the warranty replacement.

jperkosk · 08-01-2012, 12:17 AM

My understanding from reading FMA multi-chemistry charger manual is that LiFe charging is pretty much governed by the same rules as for LiPos, so nope, no trickle chargers.

TheBum · 08-01-2012, 07:47 AM

Quote:

Originally Posted by jperkosk

My understanding from reading FMA multi-chemistry charger manual is that LiFe charging is pretty much governed by the same rules as for LiPos, so nope, no trickle chargers.

Hyperion advertises the following:

Quote:

The pack includes Safety PCM circuits to allow charging inside Transmitter, using standard wall NiMH charger.

In my experience, those circuits aren't as safe as they say.

nickypoo · 08-01-2012, 10:39 AM

What is a life pack? They are safer for the tx? Stronger than a nimh?

What about these eneloops? You put them in a 8 AA harness that fits in the stock battery tray?

TheBum · 08-01-2012, 10:49 AM

Quote:

Originally Posted by nickypoo

What is a life pack? They are safer for the tx? Stronger than a nimh?

It's a lithium battery of a different formulation than lipos. The full name is LiFePO4 (lithium iron phosphate). The main advantages are their flat voltage discharge curve and nominal 3.3V/cell output, making them especially attractive as a receiver pack for LV servo setups without a regulator. The same goes for transmitter packs because there's less "excess" voltage vs. lipos when used in place of NiMH. They also tend to be less volatile than lipos.

Quote:

What about these eneloops? You put them in a 8 AA harness that fits in the stock battery tray?

You can do that or get premade packs (or get tabbed cells and solder and shrink wrap your own pack). I have a Radio Shack 8-cell battery holder with AA Eneloop cells in my DX7. In my X9303, I have a premade pack I bought here:

http://store.batteriesamerica.com/sa...eadytouse.aspx

nickypoo · 08-01-2012, 11:01 AM

Life or Sanyo?

TheBum · 08-01-2012, 11:18 AM

Quote:

Originally Posted by nickypoo

Life or Sanyo?

My link is to Sanyo packs. I don't trust lithium of any sort in transmitters anymore.

lotus7 · 08-01-2012, 11:23 AM

MMV.
I have been using the same lipo in my DX7 since end 2007. I never discharge more than 3,8V and never charge inside the tx . Same goes for my 2 sons

07-31-2012, 04:27 PM	#1
nickypoo Registered Users Join Date: Jun 2012 Location: Los Angeles, California	quick question lipo or nimh for a transmitter? about to head to the hobby shop.... should i get a stock 9.6v nimh (i think 9.6) or a 3 cell transmitter lipo? will the higher voltage damage my dx7? i just got it brand new from my boss. its an old dx7 but i got it new in the box never used

07-31-2012, 05:14 PM	#3
Maypole Registered Users Join Date: Feb 2011 Location: Austin, TX	I've run both on my DX8 and prefer the lipos. By a large margin. Longer between charges as mentioned and surplus power for the vibe/tone timer alert I use. __________________ Nano CP X, mCP X BL, 130 X (Love the little ones)T-REX 500 Efl Pro DFC Phoenix Sim, DX8, Gibson Les Paul, AMA #987871 I really think this "Internet" thing is going to catch on. You can quote me on that.

07-31-2012, 09:42 PM	#9
hANDYman Registered Users Join Date: Nov 2010 Location: Burnaby, British Columbia	Cool... good info, thanks guys. I may have to look into getting one. __________________ Dx8 / Dx7 (modded) mCPX (brushless) / FBL 450 PRO (beastX) / FBL 550E V2 (3GX) TH Edge 540 / 3DHS Extra 300 SHP / Radian Pro RealFlight 6 / iCharger 306B

07-31-2012, 10:29 PM	#10
TheBum HF Support My HF Map location Join Date: Jul 2007 Location: McKinney, TX, USA, North America, Earth, Solar System, Milky Way, Universe	I use Eneloop NiMH packs in my DX7 and X9303. You can use the stock charger and they hold their charge a lot (months) longer than regular NiMH. __________________ Alan (just call me "Bum"; no need to be so formal) HeliFreak Support Nankin Hobby Field Rep, Compass Support Team Helis: Compass Atom 500 (V-Bar), Compass Atom 6HV (V-Bar), Blade 130X, Blade mCPX Experience is something you obtain only after you need it. I wouldn't mind social media so much if it didn't involve people.

08-01-2012, 12:17 AM	#14
jperkosk Registered Users My HF Map location Join Date: Dec 2009 Location: San Luis Potosí, México	My understanding from reading FMA multi-chemistry charger manual is that LiFe charging is pretty much governed by the same rules as for LiPos, so nope, no trickle chargers. __________________ Jerry Trex 700N Pro fbl, 600N Pro x 2, 450SE v1, 250 v2 fbl, Compass 6HV fbl, Blade 450x, 400, 300x, 130x, mCPx, 120SR, mQx, mSR, Rotor Concepts HPQ1, Walkera CB180Q, CB100, Novus FP, CP, Esky Hunter, Big Lama.

07-31-2012, 04:58 PM	#2
Dajavu*Xion Join Date: May 2012 Location: las vegas	Good question and i look forward to the responces..All i know is that i have run both and only change i can tell is that the lipo last a heck of alot longer bettween charge ups.

07-31-2012, 06:35 PM	#4
tukkus Registered Users My HF Map location Join Date: Jan 2007 Location: MA. USA	If the DX7 isnt made for lipos you can buy a Tx lipo pack and solder 2 diodes together on the battery so the Tx will only see 11.2v fully charged. I have been doing that for over a year on my JR 9303 2.4 Tx with no problems. You have to take the battery pack out to charge but that is a minor inconvience. The packs are pretty cheap, roughly $20-25 and the best part for me is that they charge quickly.

07-31-2012, 09:06 PM	#7
pinguin Registered Users Join Date: Apr 2009 Location: Indonesia	If your Tx use 9.6v NiCad battery, you can use LiFe battery. The voltage close to 9.6v NiCad batt.

08-01-2012, 10:39 AM	#16
nickypoo Registered Users Thread Starter Join Date: Jun 2012 Location: Los Angeles, California	What is a life pack? They are safer for the tx? Stronger than a nimh? What about these eneloops? You put them in a 8 AA harness that fits in the stock battery tray?

08-01-2012, 11:01 AM	#18
nickypoo Registered Users Thread Starter Join Date: Jun 2012 Location: Los Angeles, California	Life or Sanyo?

08-01-2012, 11:23 AM	#20
lotus7 Registered Users My HF Map location Join Date: Aug 2007 Location: Cape Town , South Africa	MMV. I have been using the same lipo in my DX7 since end 2007. I never discharge more than 3,8V and never charge inside the tx . Same goes for my 2 sons __________________ *Lotus7* Compass 6HV Compass 600E

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