Receiver batt question
 

My LT-40 is my primary glow bird right now. But, I'm about to throw my .25 cub on the line. As such, I am looking at what receiver batt to buy. I came across this one at the LHS:

[link]http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXNRH6&P=ML[/link]

I've been using the 4.8v 600mah NR-4J battery in the LT-40 and have been getting between 5 and 7 fights on it running 5 servos and a Futaba Receiver. What I am thinking of doing is taking the battery out of the LT-40 and putting it into the cub, which only runs 4 servos, and buying the above battery to put back into the LT-40.

1. Is there any electrical weirdness I am overlooking here? (NiCAD vs. NMHi) Is this a direct replacement battery for the NR-4J?

2. With 600mah vs. 2000mah, I should be able to get 10-12 flights right? (I'll never do that many in a day anyway)

3. And most importantly, is there a cheaper place to get this batt? The LHS is a buck or so more than the tower price.

4. Can I charge this with the regular wall charger that I've been using that came with my Tx (Futaba 7C)?

Thanks!

RE: Receiver batt question
 

That battery will work just fine. Just make sure your charger will be able to charge a NiMh battery. It should say so on the charger.

RE: Receiver batt question
 

Here is one that I use- it's plenty big.

[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXMUG9&P=7]Duratrax 5 cell NiMh battery[/link]

RE: Receiver batt question
 

Geoff,
 That battery pack is a "C" cell pack and is going to add a lot of extra weight to the plane.

Byris,
Yes, you can charge a higher capacity battery with a wall wart charger. Howver, it's going to take longer to charge than the 10 hours you can charge your smaller battery in. It could take a couple days to fully charge a battery that big with that charger. I usually advise people to pick up a good charger when they start moving up to bigger batteries than what came with the plane. In this day and age it's a good bet you're going to need a good charger sooner than later. With all the changes in batteries it's well worth the money. Even if you never move past the Ni-mhs in planes it's still worth the money as you can use the charge-discharges to condition new batteries, as well as using discharge to monitor battery packs to find out when they start going bad. With a better charger you'll be able to go back to charging the bigger battery in 10 hours.

Byris,
I sent you a PM a few days ago, but it's showing that you didn't read it. Quick question. I noticed you are with the Imperial club there in Lakeland. Will you be working Florida Jets or Top Gun with the club???

Ken

RE: Receiver batt question
 

True, it is a bit on the heavy side, I guess I forget that not everyone has a 1/4 scale Super Cub that will haul half-of-a-house around!!!

RE: Receiver batt question
 

bryris,

Check this reference out:

http://www.radicalrc.com/nimhfaq.html

The battery you show will take over 33 hours with your wall charger.

RE: Receiver batt question
 

Eh, not that much... only about 2oz or so on a .40 trainer.

He's only talking about 4.8v 2000mAh packs.

Here's a direct comparison:

Hydrimax 700mAh 4.8v - 2oz [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXPYL6&P=ML]Click me 700mAh[/link]

Hydrimax 2000mAh 4.8v 4.3oz [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXNRH6&P=ML]Click me 2000mAh[/link]

The LT 40 is not going to notice the difference at all.

RE: Receiver batt question
 

Yeah, ya know, with Electrics being somewhat in the forefront (fuel availability and cost for glows and so on), and the way we have to be very careful about weight on electrics, it's easy to consider an ounce (28.xxx grams/ounce) it's easy to fall into what some small changes in batteries cost us in performance. Our glows are able to deal with small changes in weight, however, always within reason.

CGr.

RE: Receiver batt question
 

Any good website for JR radio's battery pack size from 1500 Nimh to 2400 nimh not necessarily made by JR by any generic company with JR connector for TX along with the TX and RX nimh charger for JR, does anybody have any idea or any good online website?


Mody

RE: Receiver batt question
 

http://www.radicalrc.com/shop/?shop=...340&cat=19

RE: Receiver batt question
 

It seems in the case of a receiver batt, the 600mah batt will be fine. I can get one for cheap at servocity. I don't see a benefit of charging for 22 hours - I'll never fly 10-12 flights on a charge. I rarely have less than two planes at the field. With 4 or 5 good flights on a receiver batt over two planes, that is plenty of flying - plus I am flying my electric a lot these days with lipo batts that are constantly revolving through the field charger.

RE: Receiver batt question
 

One advantage of the 600 mAh NiCd battery is that they last a really long time. I have some that are 10 years old and still have good capacities and good self-discharge rates. My experience with higher capacity AA cells (both NiCd and NiMH) is that they don't last nearly as long. More like 3 or 4 years.

RE: Receiver batt question
 

I hate to throw this into the mix but you can also get a lighter weight lipo battery if you already have a charger for it for all the mAh you want (say 1000mAh 11.1 volt just for fun) and run it through a capacitor/regulator to drop the voltage for your 4.8-6 volt rx..Rog

RE: Receiver batt question
 

A cheaper place to get those batteries is a store named Dahanbay on e-bay. Great batteries at great prices I buy all my stuff from there. Tower is a little pricey on batteries.

http://stores.ebay.com/DaHanBay?_rdc=1

Hope this helps

RE: Receiver batt question
 

Thanks RCKen,

I have used Nicad mostly and I have been using Nimh as well. I'm getting a good price on ebay for Li-Po that is having JR's connector as I'm using JR XF421EX. I'm still unable to find the charger for Li-Po battery pack for JR's Transmitter. Haven't found any good wall charger for Li-Po, as I know that Nicad and Nimh don't work with Li-Po.

Mody

RE: Receiver batt question
 

Here is what I found

http://cgi.ebay.com/ws/eBayISAPI.dll...id=p2759.l1259

I'm still unable to find out the wall charger for Li-po battery packs with JR connectors.

RE: Receiver batt question
 

And you more than likely won't find any. Li-po batteries require a better charger than a wall charger where you simply plug the battery in and forget it. Li-po batteries can burst and catch fire if they are properly cared for and charged correctly. You'll need to find a charger that is designed for charging Lithium batteries, preferably one that can balance charge the battery.

Ken

RE: Receiver batt question
 

Kens right you wont find a plug in wall charger for a lipo,,there are a few cheap 12 volt chargers, but even they are usually for specific sized lipo's that come with the plane/batt/charger cheapo stuff....Rog

RE: Receiver batt question
 

Well,

I did my own research, yes, Li-po's are too much to maintain and balancing is another issue, I found the charger of it, but unlike wall chargers it's nothing like any charger, it needs a 12 to 15 volt input, and li-pos are not supposed to be charged more than 1amp, so it's so much for me, so I have decided to goto nimh, I ready so many things about nicd as well, some say nicad is better, some say nimh is better, I think performance wise nimh is more better, rectify me if I'm wrong

RE: Receiver batt question
 

I like the NIMH better than the NICAD because of capacity. One thing to be aware of is they self discharge at double the rate of NICAD. So a fresh charge is a good thing before flying if it's been a while since your last flight. LIPO's are great but like you not for me. Just seems like a lot of cost for batteries and charger for a receiver battery. But my setups are simple. If my models were as intricate as many I would probably look into it.

RE: Receiver batt question
 

On a good overnight charge on nimh 2700 mah battery pack for TX, how many flights would it give easily or I would say, how long the charge is gonna stay and drainage would be 270mah?

Mody

RE: Receiver batt question
 

These are my favorite type of batteries. The 5 cell 2/3 A size NiMH. Normally I get plenty of flights in a day without recharge. They have much greater current available than AA size batteries to keep high draw servos happy and at the same time hold the voltage up for the ever more critical spread spectrum receivers. The weight is slightly less than a AA size. They do have less overall capacity than some AA batteries and NiMH do have more self discharge than NiCd so charge them the day of use. Wall wart chargers won’t satisfactory charge the 5 cell 2/3 A size NiCd.

http://www3.towerhobbies.com/cgi-bin...?&I=LXTYW4&P=7


The H9 Double Vision charger. I have used them for years and love it. It quickly charges my TX, RX and Ni starter AT THE SAME TIME! When it’s done it goes into trickle charge. It automatically does NiMH or NiCd. Nice charge indicators at a glance. If it stop’s a charge before full, your pack may be no good so you may want to test the pack to be sure. This may have saved a few planes. (new packs may false peak, just restart, but bad packs refuse keep charging and quickly shut off).

Just don’t reverse the supply power clips, the diode protection is worthless and you WILL kill the charger.
http://www.hangar-9.com/Products/Def...?ProdID=HAN114

RE: Receiver batt question
 

Thanks,

I think I'm gonna buy me 2600 nimh battery pack, and going to buy the JR's TX charger that would do it all. Thanks for the info.

Mody

RE: Receiver batt question
 

This is the only JR charger that will charge that pack for you fully.
http://www.jrradios.com/Products/Tec...ProdID=JRPC223

From depleted to full would take about 16 hours, but most of the time you most likely would not need to do this other than the fist time so over night will do....unless you left your TX on. This "wont do it all" as it only charges the TX. It is also dumb, as it can not tell you state of charge. It is inexpensive. Other JR combo RX/TX chargers don't have current needed to fully charge that large of mah battery nor are they for NiMH (not including the JR 12X only NiMH system).

With a good charge a 2600 NiMH TX pack will give you more flying time than most would care for before needing a charge. Just remember that NiMH self discharge quickly so a few days after a charge is too long, charge the night before and if you forgot, you'd wish you had a quick charger because now your out of time.

RE: Receiver batt question
 

Thats the charger I want, and I looked it up on the internet, that only charges TX not RX but anyway, it's good enough for my needs. Thats what I'm gonna buy.
Thanks a lot for informative advice. I'm gonna act upon it:D

Mody