waditup1

Hello Folks.
I have just bought the new Dx7.I love the the radio but the AAcells don't seem to last as well I would like . I want to replace them with a lipo. Specktrum sells one for about $70.00.
I think that is too high.I know somebody has got to be offering a cheaper one.
I know some out there has the answer and would to share.
Thankyou for your time and advice
Waditup

Goldenduff

I wouldn't use a lipo- you have to remove to charge/balance, supervise during charging due to fire hazard if you accidentally leave Tx on you will ruin battery and some radios protect this by turning off once a voltage is reached (weather you are in the air or not!!!)

John C

Look at the HobbyKing website. They have specialized LoPos for Tx use that must be charged at 1C and are 3S, 2600 mah capacity. I put one in my JR 9303 and love it. If you have a voltage display, you can watch it slowly lose voltage and recharge when convenient. I've found at 11V showing, I have used 1/2 of the battery capacity. I've read that 10V is a good lower cutoff for this setup, but I need to recharge so seldom that I typically recharge at 11V. The battery is purported to no need a storage charge, but can be left at full charge with no ill effects. I got mine this spring, and no issues. It has the appropriate plugs to balance charge already installed. Yea, you've got to take the back off your Tx and pull out the wires to charge, but no big deal.


John C

countilaw

I would have and have gone with the nimh. If you do try to use the lipo, you should put a voltage regulator in your Tx. There are several other places to get lipos right here in the states. Before you spend your money with HK, check their customer ratings. They have low prices, but no customer service and remember, you pay for what you get.

I recommend the Sanyo batteries.

Frank

waditup1

Thanks for the advice..
Waditup

Bozarth

My Feedback: (15)

I have been using the Dualsky TXB18003-9c 3 cell lipo in my DX7 for the past 4 years and LOVE it. No big deal to pull it out and change it. I also use them on my Futaba 9CAPs. Best thing since sliced bread!

Kurt

fizzwater2

My Feedback: (61)

Is this a dx7 or the new dx7s

Bozarth

My Feedback: (15)

I have the DX7 - I bought it years ago when the DX7 first came out (following the release of their DX6).

Kurt

PLANE JIM

My Feedback: (109)

I have a DX7 that I have been using for four years-installed lipo 2 years ago with no problems and no regulator. I charged the battery out of transmitter and and balance. I only have to charge once every 4 months or so. I use this transmitter seldom. But the lipo's were the way to go.

Bozarth

My Feedback: (15)

Exactly the same for me.

Kurt

dirtybird

My Feedback: (5)

If you put a lipo in your transmitter you have to:
1. Remove it to charge it
2. Watch the battery while it is charging.
3. Never let the voltage get to a certain level.
4. You need a special charger.
5. If you forget to turn off your transmitter you will ruin the battery and possibly ruin you transmitter.
6. Never store your transmitter in your trunk if it a hot day. In the summer my garage can get to 140 degrees. I have to take all my lipos out and store them in the refrig.
7. For some transmitters you need a regulator.

Why anyone wants to put up with all of that just so he has to charge it a few less times is beyond me.
Eneloops will hold 75% of their charge for three years, you can charge them with your charger and there is no chance of fire.

Goldenduff

I couldn't agree more! In a post not long ago a guy lost an expensive plane because the Tx had a low voltage cut off and despite plenty of power in the lipo it shut off......needless to say plane was a right off!

Bozarth

My Feedback: (15)

1. Remove it to charge it - NOT TOO DIFFICULT.
2. Watch the battery while it is charging. NOT TO DIFFICULT, Especially if I'm in my shop charging a bunch of my other lipos
3. Never let the voltage get to a certain level. Hasn't been a problem in over 4 years and I haven't worried about it one time.
4. You need a special charger. Most people considering lipos for a TX probably have a charger
5. If you forget to turn off your transmitter you will ruin the battery and possibly ruin you transmitter. I turn my transmitters off after each flight. Hasn't been an issue.
6. Never store your transmitter in your trunk if it a hot day. In the summer my garage can get to 140 degrees. I have to take all my lipos out and store them in the refrig. I wouldn't store anything in a trunk, regardless of what temp. it was.
7. For some transmitters you need a regulator. I have used lipos in 8UAPs, 9CAPs, and DX7's without the need for a regulator.

Lipos in a TX are a fine option.

Kurt

dirtybird

My Feedback: (5)

Its still beyond me why you want to do it.

Bozarth

My Feedback: (15)

It is to enjoy the advancements in technology.

Kurt

Goldenduff

Hello- eneloops are an advancement. Also dirty bird you didn't address the issue someone had that their Tx shut down because it though the voltage of the battery was too low.

pilotpete2

The newer generation radios are being designed to use Lipos and/or LiFe. Futaba, Hitec, Airtronics, JR and Spektrum are all going this route.
I put a 2500mAh GeForce 2S lipo (specifically made for the 8/12FG) from Value Hobby in my 8FG, price is 1/3rd that of a replacement Nimh. I set my low voltage warning a little higher than Futaba suggests and if I were to put it in the radio case turned on, the radio would shut off at 5.5V, so the battery would not be run dead flat. I get up to 10 hours of run time on a charge without hitting LVW. Charging the battery at the field during lunch or coffee break is more convenient than having to remember to bring the radio in the house and put it on the overnite charger.
If you fly lipo powered models and use a good quality balancing charger.
The only risk putting a lipo in a transmitter is that you may forget and plug in the stock charger. I put a little square piece of vinyl electrical tape over the charge port as a reminder that I have the lipo in use. The other issue so often mentioned is the danger of running the Lipo dead by leaving the Tx turned on. Sorry, but that's how you render a damaged Lipo safe for disposal. I personally have ruined more than one Lipo by losing a plane for a month or so, or having it held hostage by a large tree for an extended time. Never have I seen a battery puff when slowly discharged to zero, and when discharged to zero a Lipo poses absolutely no fire risk at all. There's a big difference between over discharging a Lipo under a light load in a radio and running one hard at over 10C in an airplane to too low a voltage.
Pete

dirtybird

My Feedback: (5)

There is a big difference between Lipo and Life. Life takes care of most of my objections.
I sure will not buy a transmitter if its designed for Lipo's.

Flypaper 2

Used a HK lipo in my DX7 for yrs with no problems. Even killed it twice by leaving it on over night. Brought it back with no problems. Took it out when I sold the trans. when I bought the DX8. That was one of the first DX8s that came out and had the problems. Had to send it in for a replacement and bought another DX7 to use in the meantime and put the lipo in it from the first trans. They sent me a new DX8 that has been flawless since other than the nimh only lasted about 3 months before it took a dump. Promptly put a lipo in it from HK and has been working fine since. Lasts more than 2 months between charges with hard use.

Gord.

opjose

Only having to charge your battery once a month or more.

I charge every two or three weeks to be safe but it sure is nice not having to obcess about it before going flying.

The LiPo packs from HK are cheap enough that I usually take a fully charged spare out too, though I've never used it.

dirtybird

My Feedback: (5)

I bought a Multiplex radio in 2007 and converted it to 2.4ghz immediately.
It came with a NIMH battery that I found I needed to charge about once every six weeks.
I don't fly a lot but I do a lot of testing. Converting it to 2.4 reduced the load on the battery.
It still has the battery it came with. I still have to charge it about once every six weeks.