vertical grimmace

My Feedback: (1)

I am getting ready to build several .15 sized models and am wondering what the batteries of choice are these days? I have been flying bigger models and using 2600 mah A125 packs. They are way too big for what I am doing. Maybe a small Life pack? Just curious where things are at now a days for the smaller planes, and the modern battery technology.

Tee Bee

Lots of guys are running 2S lipos with voltage regulators for their small planes. I'm still using NiMH packs from Radical RC for my small glow stuff. I still find them reliable if they are form charged from time to time as recommended on their web site.

vertical grimmace

My Feedback: (1)

How about something like this? http://www3.towerhobbies.com/cgi-bin...&I=LXDVBZ&P=ML

Pond Skipper

2.6oz / 73g is a bit over kill weight wise however 1,300mah is for sure over kill.
you only need 500 -700 tops for 4 servos suitable for a .15 size plane. Should yield
at least 5 flights with plenty of power to spare.

As a example I have used 460 mah (charged) for a .010 size plane getting 5 flights per session
was enough flying for me and left 210 mah in the pack.

fizzwater2

My Feedback: (61)

Quite a few people I know have been having good success with these 700 mah LiFePO4 packs

https://hobbyking.com/en_us/zippy-fl...iver-pack.html

vertical grimmace

My Feedback: (1)

Dang, that Zippy battery is small! That may be the way to go. Thanks.

vertical grimmace

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Another question. Has anyone ever tried to use a servo lead as an on off switch for the RX? Kind of like those deans arming connectors guys use when powering up their electric motor systems. This thought just occurred to me that it may be a viable solution for the RX switch, a common failure point.

Also, since I will be placing an order with HK most likely, what are some servo preferences? No problems with these small batteries and digital servos?

MJD

My Feedback: (1)

Yes you can make servo lead shorting plug switches, they work fine. Throw a female connector in series with the +ve lead, using the outside pins so orientation doesn't matter, and make a shorting plug from a male connector or spare lead.

I use little twin pin sets of these to make tiny shorting plugs that work and feel like they'd take about 275 gees to come apart. The female connector side is all you need.



I use the 700mAh ZIppy in several aircraft now, and with small servos use a 3A or 5A (forget, small and cheap) HK regulator as I did in the Mini Contender/.15. I've yet to drain the battery any significant amount in one flying day, and it holds charge for ages, esp. compared to NiCd/NiMH. I feel so much more confident with these than I ever did with NiMH.. I know others like them but I tossed all my small NiMH packs, they're the one thing I've ever used that I completely mistrust after several bad experiences (even if it is my fault, that's not the issue really).

vertical grimmace

My Feedback: (1)

Yeah, I was thinking something like the Bind plug used in the Hitech RX. Just a male plug with a jumper wire.

Especially with the advent of 2.4, Nimh are especially bad. I have lost many planes because of them. The new battery chemistries are so much better.

MJD

My Feedback: (1)

No doubt they work, of course, but my impression was that they were always threatening some kind of mischief and I just did not enjoy having battery systems that gave me trouble with any sense of regularity. Had there been - or had I found - a good commercial charger with C/10 rates well below 100mA and automatic lotion dispenser for cranky NiMH cells, then maybe I wouldn't be so jaded.

While LiPo and LiFe batteries have their own issues to watch for.. the fact that the industry offers a wealth affordable chargers with effective battery management for the small packs, and that the signs of trouble are pretty easy to ID, they are working just dandy for me. I remember now - in the Mini Contender, it's a Zippy 700 LIFe but it's a Novak 3A regulator that has a tiny switch. Those are likely dried up now, and the equivalent would be 1/4 - 1/3 the price at HK anyhow.

The last time I used a NiCd battery pack, was in fact when I needed over a pound of noseweight in something so in went a big 5 cell pack. I still am happy to use NiCd if and when needed, they seem to behave for me. But I am now officially spoiled for lithium based Rx packs.

Those little PC board connectors can handle all the current you'll ever need on a small model. Unless it's in the motor circuit.

Rubbernecker

My Feedback: (22)

+ 1 on these for small planes. We have gone over-board on batteries. Years ago, 4 servos and a 500 mah pack was all that was ever used and it did fine. Now I know digital servos pull more, but for most small applications, small battery packs are fine.


John

tewitt1949

I use small nicad battarys from radicalrc.com They are the size of 4 AAA battarys. never had a problem

H5606

Wondering of any feedback on Eneloop batteries - a form of NiMH that a couple people I know around here swear by - saying they hold a charge over an extended period when compared to most NiCad/NiMHs.

I'm thinking about putting together a pack of 5 AAA (6V) for Spektrum receivers to try out for 1/2A - I'm sure still not as light as LiPo w/regulator or LiFe equipped - but more user friendly(?) ... or not?

BTW, Tower also has a tiny 200 MAh LiFe pack that I haven't heard anything about or tried yet; historically speaking, it seemed short order that my 250 MAh rated NiCads never gave more than half that 250 when cycled...

vertical grimmace

My Feedback: (1)

I have a number of Eneloop packs. I can't remember if I had any issues, but I had decided long ago to move on from the Nimh chemistry. I have been very happy with my A123's, but was looking for something smaller for a .15-.25 sized plane. The size I wanted has been out of stock everywhere, so I went with 1000 mah, Turnigy 6.6 volt Life packs from Hobby king. They were like $5, and still very small for the amount of capacity.

MJD

My Feedback: (1)

What I'd say in support of over-sized but still light lithium battery Rx packs, is the very low self-discharge rate and the predictability which gives me far more peace of mind than I ever experienced before when accumulating Rx pack time over a weekend or event. And so far nothing to ruin the honeymoon.

An alternate to the Zippy 700 LiFe could be say a 500mAh 2S LiPo (36g) with a compact 5A BEC at 11-12g for a hair under 50 grams, about equal to two AA NiCD cells plus solder and harness. But the Zippy 700 rocks for smaller aircraft.

DaveP

I use Eneloop cells on all my glow-powered planes - much better than NiCads or older NiMH, hold their charge for months and never had one go bad. I run FrSky gear, and 4 cells is plenty. AAA on my .049 to .15 planes, AA cells on larger. I've also bought a couple of HobbyKing low-self-discharge NiMH packs, but have only a year or 2 experience with them - okay so far.

My Eneloops on glow planes outlive the LiPos on my electrics and are much more user-friendly, so I see no reason to switch.

-Dave Plumpe

MJD

My Feedback: (1)

In the end a system that works well and that you're happy and comfortable with is the best one. I have a few Eneloops and was about to dive into using those when - due to being behind the times - I realized the lithium options out there and headed straight in that direction.

MJD

My Feedback: (1)

The Zippy 700 LiFe's show up in stock now at the global HK warehouse.

41g, 700mAh, 6.6v, $6.00.

13g x 4 + harness so maybe 55g, 900+ mAh, 4.8V, $15.00 (Eneloop AAA)

Both pretty good choices, similar capacity/weight, both very inexpensive. 20 years ago, how much did a 225mAh Nicad pack cost?