RC India

Hey guys,
I had bought a Futaba Skysport 4VF radio from the US about 5-6 years back.. Then i kinda got busy with stuff n never ended up doing anything with it.. The first year and a half or so i used to charge and discharge the nicads to keep them healthy.. Then my friend borrowed my 220-110v converter and lost it, being the lazy bum that i am i never got around to  buying another one n my nicads sat idle all these years due to lack the converter.. I just unpacked my stuff this week and checked the voltages on the nicads.. The Rx batt was showing a decent voltage while the Tx batt (8 cell 9.6v pack) was showing 2.8 or so volts  :(

I've just bought a converter and put my batts for charging.. Will they work properly or will i need to get/make a new pack? Can some experts pls tell me what to do? Also has anyone here made their own pack? (my soldering skills are pretty decent) 

Will see what happens after i finish charging n post the results here.. Till then, pls join me in praying to the battery gods!!

Hey battery gods!! Please do good for medicineman1987's batteries  ;D

Hope this helps ;)

Read the thread having similar discussion. Battery packs are available with 2-3 LHS and it would be better to buy a professionally manufactured pack. Soldering the normal NiCd/NiMh cells are not recommended. You need to buy special cells with soldering 'Tabs' on them and not the one with depression and notches on neg/pos ends found off the shelf. Even the use of battery holder are risky as testified by Vinay in the same thread.

Other popular option is going LiPo Tx pack! if you already fly EP planes and have a decent LiPo balancer, this would give a great value for money.

If your TX supports it.

Hmm.. so soldering a pack of my own is outta the question.. Any idea if storing the battery packs for so long damages it? Right now i'm charging the packs and will test them after about 8 hrs of charging.. will post the results after i test..
Can u post a link to that thread?
I doubt it supports lipos..

Seems to be helping..   :bow:

Just checked the voltage on the pack that was showing 2.8volts, n it seems to be charging.. although this is probably cause i tested it soon after removing it off the charger.. im still keeping my hopes up..  :)

Try cycling the batteries - charge - discharge - charge discharge for a few times and see. It will increase its capacity.

Will do that..  :)


Can someone point me to this discussion?

Apologies. I copied thread URL and left it in the 'Clipboard' Here it goes
http://www.rcindia.org/wanted/tx-lipo-for-futaba-10c/msg18662/#msg18662

may the gods of the battery be with your nicads

this combined with vinay bhaiya's post would surely wake the gods up and throw some life back into your nicads

subbu

 ;D ;D ;D :giggle: :giggle: :giggle:

If u guys keep praying so furiously i dont think i'll ever have to buy another nicad again!  ;D ;D ;D

Apology accepted  ;D
Reading that thread right now.. Thanks  :)

It is extremely unlikely that your batteries will be up to capacity, even if they charge to normal voltage.

If your soldering skills are good I see no harm in making your own packs. I have been doing so for more than 20 years and ALL my present models use them. I have also made several for other modellers, without issues of any kind. Now that LSD NiMh cells are available at very reasonable prices, this is a sensible, low cost option which will also retain your present charger set up. Will need to compensate with increased charge times, though.

I was thinking of using NiMh cells too.. I guess i'll give it a try.. Do you use normal cells or do you use the special tabbed ones?

Sir, if i use my present setup with NiMh cells, how do i calculate the charge time required? As in how much percentage extra should i charge over the capacity of the battery?
Also which brand/capacity LSD NiMh cells do you recommend?

If you have soldering experience then you can make your own battery packs. I am doing that ever since I started this hobby some 10+ years ago. Also since Futaba uses battery packs of 8AA cells placed side by side configuration soldering the cells together is relatively easy than in case of Hitec which uses 2 x 4 cell cylindrical shaped battery packs which makes soldering cells a bit tricky.

The Ni-Cd/ Ni-mH battery packs come without any charge in them and the 1st charge becomes very important. The 1st charge MUST always be done at 0.1 C rate for 15 hrs. This is called conditioning charge and is very important for the battery pack to attain its full capacity. After this conditioning charge you can use the battery pack and charge it with your overnight wall chargers that come with the Radio Systems or you can use Peak detection chargers to fast charge the battery pack outside your Tx like I do.

Standard Charge time for Ni-cd/Ni-mh  is o.1 C amps for 15 hrs. I fast charge my Radio battery packs at 0.5 C amps using peak detection chargers (approx 2 hrs).

Also cycling a battery pack at standard charge rate once in a while keeps the battery packs healthy and improve their performance/Life.

I use SANYO Eneloop cells that are rated at 2000 mAH. They are available for 350 a pair against their MRP of 450. They specify 85% residual charge after ONE YEAR!

Charging rate x time (in hours) + 15% is the norm. So if your charger is rated at 100 mA you would charge these cells for 23 hrs. If your charging rate is less than 0.15C then they can be left to charge indefinitely, without problem.

My Futaba 9Z WC2 uses a "2x4" configuration.

I have reservations on peak detection chargers. They often read a false peak and cut off before full charge. If you have a charger that goes into "trickle" mode after peak detection, then it's fine. Otherwise there is every possibility of having as little as 80-85% charge.

I have a sanyo eneloop charger. they charge eneloops well but they overcharge my turnigy LSDs. cells become really hot. So I charge my turnigy LSDs on my lipo charger 8 at a time.

1. What is the rating of the Turnigy cells? I presume you have the 2000mAH Eneloops.
2. Do you mean you use the LiPo setting on your charger?

I am using PIRANHA AC/DC Digital Peak Detection Charger which can charge 1 to 8 cells for the past 10 yrs. Works flawless. It has Trickle Charge facility. You can also select the peak detection sensitivity value for both Ni-Cd and Ni-mH Batteries depending on how old your battery packs are to prevent false peak detections.

I have already said that a trickle mode after peak detection works. How does one determine "how old " the packs are to set sensitivity? And what does one do with different packs? Not very practical to keep track of individual packs.

Try this experiment. Charge your batteries normally WITHOUT trickle mode. When complete, put them on charge again. Very often, if not most of the time, they will take in a significant amount of charge, indicating that the first peak was false.

Hi guys, I checked my transmitter after the overnight charge and am pleased to tell you that its working :) The transmitter worked for about 3+ hours with juice still left in it.. Is this normal amount of time for a Futaba Skysport 4VF?

N i would like to thank all the people who prayed to the battery gods for my Nicads.. Its all u peoples prayers that pulled my batteries through..  ;D ;D ;D

Should be enough for you! ;D

Turnigy are 2200 and enloops 2000.
No, I use the Nimh settings on the charger. Its a 50 watts Thunder AC6 charger.