DX6i batteries

[highflyer50]

what is the best batteries to use with the DX6i Tx right now I;m using

energizer rechargeable 2400 mah and they seem to not last on full

charge it shows 6v on the DX6i and drops to 5.1 after 1st flight

thanks

[geoff2474]

Mar 21, 2011 5:54:52 GMT 1 @highflyer50 said:

what is the best batteries to use with the DX6i Tx right now I;m using

energizer rechargeable 2400 mah and they seem to not last on full

charge it shows 6v on the DX6i and drops to 5.1 after 1st flight

thanks

Hi
I use Duracell Rechargeable 2450mah. They last very well. I use them on the sim as well and an hour of use only drops them by about .8volt.
Are you sure you are getting plenty of charge into the batteries, Nimh can be difficult to bulk charge successfully. Also are you sure you have not got a duff cell, that would degrade the whole pack.

Geoff

[ginginho]

I use Uniross long life rechargables (bit like Eneloops), 2000mAh IIRC. They last for ages and rarely need to recharge. Geoff may have touched on you problem, not fully charged or a dud.

[highflyer50]

I just checked the batteries I see 2 of them are 2500amh and other

2 are 2450amh I bought them at same time I take it that is not good

? the charger I got off ebay for 9 bucks that charges 8 at a time but

takes 8 hours to charge so what would be a good charger to get ?

thanks

[flydiver]

Alkaline AA = 1.5v fresh
NiMh AA = 1.4v fresh but RAPIDLY drop to ~ 1.2v. Then they hang in there a good while. What you are seeing is normal for NiMh. As long as the voltage stabilizes in the 4.8-5.2 range (1.2v x 4 = 4.8v) and hangs in well for a flying session you are good. You can turn it on a just leave it until you get the low voltage alarm and find out how long it will really go. You'll probably be surprised.

The alkalines have a linear discharge, start out higher, but drop below a decent NiMh in not too long and just keep going. That said I DO keep a spare set of alkaline with me. The way NiMh drop at the end of their charge (~1v/cell) you do not want to push your luck when you get low voltage alarm.

Do some reading here-it's well worth it.
www.powerstream.com/NiMH.htm

High capacity (cheap non-brand name) AA are sometimes poor quality and have high self-discharge. Non LSD (long slow discharge) NiMh cells will lose about 10% of their charge within 24 hours and then slow down to ~ 1-2%/day. That is normal NiMh behavior.
Cheap NiXX chargers are ...... cheap, same as cheap lipo chargers. Slow overnight chargers can be just fine as long as you understand how they work vs. faster peak chargers. Both have their place. If you don't know the difference it'll frustrate you.

If you want to step up get some Sanyo Eneloop low self discharge. These are about the best AA out there.
www.thomasdistributing.com/Sanyo-Eneloop_c_1020.html?frontpage=1
Sometimes Costco sells a large bunch + charger (medium slow timed charger) for $25.

If you want true step up in a charger try this one-but it'll cost you:
www.thomasdistributing.com/Maha-MH-C9000-Advanced-Battery-Charger_p_2558.html
That's actually a re-branded La Crosse Technology BC-9009 AlphaPower Battery Charger
www.amazon.com/Crosse-Technology-BC-9009-AlphaPower-Battery/dp/B00077AA5Q

The Accucel AC-6 charger that everyone likes for lipos does a pretty good job on NiXX too once you figure it out. NOT as easy to use as above dedicated chargers. It is less expensive and you need to make up a cell holder (Radio Shack or electronics store) AND have a power source so not too portable. But it will do all your batteries.

People think NiXX batteries should be easy to take care of. They are WAY harder to take care of PROPERLY than lipo, they just aren't as dangerous or as easy to permanently screw up.

[highflyer50]

thank you very much another thing learned today yeah I also have the

AC-6 charger but don't want to mess with that I seen one on amazon

a powerex MH-C800s eight cell smart charger for $47.95 and powerex

2700amh NiMH batteries for $ 11.75 thinking on getting it unless there

is a better one but don't want to spend alot for $$ on it

[flydiver]

I suggest you take the time to learn the AC-6. It'll give you a lot of info about your batteries.
But if you don't want to the powerex is an EXCELLENT charger. I have the AAA > D bigger model. It doesn't give you charging info but it does a great job. A good 'no brainer' charger.

DO NOT get high capacity NiMh. It's mostly pure marketing BS. The higher the mA, the WORSE the self-discharge. I've got ~ 20 of those in my 'to recycle' bin right now. Learned that the hard way. Garbage. Sound great on paper but lead to serious disappointment. Think of them as a larger bucket but with a corresponding large leak. If you charge them and use them RIGHT NOW, they work OK. You are better off with a smaller bucket and a tiny tiny leak.

Just suck it up and get the Eneloops. They don't seem as good (2000mA) but the functional reality is they are a LOT better. They WORK.
If you left those 2700 sit in your TX for 3 months without use they would be almost dead. The Eneloops would have something like 90% of their charge left.

ALL rechargeables WILL act as I described above: start at 1.4v > drop fairly rapidly to 1.2v > hang in there pretty well until 1v and then DROP like a rock.
ALL OF THEM.

What you have now may be working fine. Don't compare alkaline to NiMh. They don't work the same. 4.8v on your DX6i is just fine. Won't hurt a thing, won't cut your range, won't die in the next 10 minutes, so you may need to just re-think how to look at it.

For example - I use an 8-cell TX. At absolutely FULL/WARM charge it will read 12v. Let it cool down and it RAPIDLY drops to 11.4v. Use it for an hour and it's in the mid-10v range and stays there for a LONG time. Then it slowly starts dropping to the low 10's, then the high 9's. Low voltage alarm is 9v and the nasty drop-off isn't until ~ 8v so I have a LOT of lattitude.

[highflyer50]

ok will learn the AC-6 good to know about the high mah good thing was going to get 4 sets will try the lower mah thanks

[Dillzio]

assuming that the DX6 uses 8 AA batteries like most transmitters, running off 12v, you can adapt it to run off an old 3S lipo.

I have an old lipo that I got for my original cub, and it works just fine in my transmitter (the HobbyKing T6A). The transmitter also changes to an orange, then red light when the batteries get low (under 10v), so you also get a nice little indicator warning you when your lipos are getting too low. I've even accidentally completely discharged the battery a couple of times, and it's still going strong. Since the current draw from the transmitter is so low, the 3S handles it no problems, no puffing or anything like that despite the crappy quality of the lipo, and the crap job I've done of taking care of it.

[flydiver]

It's a 4-cell TX. There is no lipo option.

[ginginho]

Mar 22, 2011 6:24:56 GMT 1 flydiver said:

It's a 4-cell TX. There is no lipo option.

Indeed. In the UK there have been some calls for people to convert from individual cells to a 4 cell pack with a proper connector as there have been concerns that the battery cover can come adrift and the cells drop out leaving the flier with no control. Personally I think this is a bit OTT, I checked the cover on mine and it's a good tight connection. I put a piece of tape over it anyway so that there's no way it can come off on it's own. Agree about the high mA Nihm's. Other battery manufacturers make LSD cells other than Sanyo's Eneloops, so you are not tied to trying to source this particular type. I believe the technology was invented by Sanyo, hence these are the de facto brand.
Some background info and performance tests of various makes (for a different application, camera kit) can be found here.
P.S. I use Uniross' in my 6i as a store in the UK was selling them at 50% off and I'd had enough of eating through Duracells. More luck than judgement that I have the winner of the tests!

[flydiver]

That's a good link. Having paved the way by Eneloops there are now a bunch of LSD batteries coming out. It's not to hard to performance test them. The REAL test will be longevity, performance over time.

I indicated earlier that I did buy some high capacity NiMh a couple years back. Many of them are garbage now. I also have some med. cap (~1500mA) that are YEARS old and still work just fine. I have some NiCads (only about 600-700mA) that are almost a decade old and still work.

There are some truly GOOD NiMh (finally!) but there is also so complete garbage that continues to give the chemistry a bad name. Combine that with crap chargers and woeful ignorance about proper care and it's a wonder folks even bother.

[john66]

Just noticed HK sell these, I have no idea on their performance though.......

www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10456

John

[flydiver]

I have some I got less than a month ago to try out, essentially replacing the ones I'm moaning about. Initial impression is decent. Like I said, really won't know for a couple years. Capacity seems about correct (this is hard to measure accurately in NiMh). Since there is little correlation between capacity and voltage in NiMh you can't just let them sit and check the voltage once in awhile. You have to do a capacity test (discharge > charge) effectively resetting the LSD clock.

I can tell you the price is cheap but the shipping takes a nasty bite out of the saving making them less of a bargain than they first appear. You'd maybe save $2-3 on 4 cells.

For a mission critical device like your TX I still suggest going with a known good product with a proven track record----Eneloop.

[john66]

See what you mean about the shipping!

John