Hi All,
I finally fried up my 110V input Futaba Tx/RX charger when I accidentally plugged it into the 220volt AC supply without the 220 to 110volt converter.This happened when I was retro fitting my SkyCharger B6AC Balanced Charger (http://www.xheli.com/skychb6durcc.html ) charging lead for fitting to my Futaba T7c 2.4G Tx (with stock 600mAh NiCd cells).

Anybody using his A6/B6 Lipo Balance charger to regularly charge his Futaba Tx using the charger lead (not taking out the battery and directly connecting to the charger) ? It is safe to use the Balance Charger's NiCd program ?

any +/- review would save me for possible damage to my Tx, getting one locally is already becoming a tough thinggy.

-Ujjwal

The Futaba 7C should charge fine with the B6, as it is a delta peak charger.  I have done with the non-2.4Ghz version of the TX. I put it 0.2amps and charge for many hours.  Rarely, I did a few fast charges at around 0.8A.

Thanks Anwar bhai for the quick reply! did you use the Tx Charger Socket and charged the batter inside th charger or taken the battery out and then charged it ?

The problem is that, unlike for LiPos, the B6 does not let you to select the number of NiCd/NiMh Cells and totally depends on automatically 'Sensing' the number for cells in series to charge the batteries, which is a little scary.

TIA,
Ujjwal

Go ahead.. no issues with B6 charging the Futaba battery in the Tx. I always used to charge my NiCd in the Tx with the charging lead. As pointed out rightly by Anwar, this is a delta peak charger, so wont overcharge your batteries.

But do not charge your Lipos in TX !!!

Cheers !!!

Quote from: ujjwaana on December 14, 2009, 03:16:19 PM
Thanks Anwar bhai for the quick reply! did you use the Tx Charger Socket and charged the batter inside th charger or taken the battery out and then charged it ?

The problem is that, unlike for LiPos, the B6 does not let you to select the number of NiCd/NiMh Cells and totally depends on automatically 'Sensing' the number for cells in series to charge the batteries, which is a little scary.

I mean directly (with the battery inside the TX), using the supplied TX charger cable.

Since they use delta peaks, it is not an issue.

Will work fine on Txs that do not have an internal diode. Mine does and it is INSIDE the battery pack!

with d diode you will nt b able to discharge/cycle d battery
but u will still be a able to charge d battery. anyways cycling a battery in the tx is nt a good idea...

cheers!

Thanks every one for the replies. I am overwhelmed!   
I anyway haven't broke-in my NiCd yet and already had  4-5 charge-full Discharge (Tx beep) cycles file using Tx on SIM . Would now breaking in the Battery make sens ? I so I would do it sooner with the battery off the Tx.

BTW, this should work for the other common Futaba TX models, the 6EX and the 9C.

Quote from: ujjwaana on December 14, 2009, 09:42:12 PM
Thanks every one for the replies. I am overwhelmed!   
I anyway haven't broke-in my NiCd yet and already had  4-5 charge-full Discharge (Tx beep) cycles file using Tx on SIM . Would now breaking in the Battery make sens ? I so I would do it sooner with the battery off the Tx.

Hi,

Cycling a Nicd every 40-45 days is a good idea (deep discharge - Full Charge)... or else the memory effect can cause capacity reduction..

Cheers !!!

Quotewith d diode you will nt b able to discharge/cycle d battery
but u will still be a able to charge d battery. anyways cycling a battery in the tx is nt a good idea...

Not with the BC-6 - which was the original thread. The diode prevents the charger from "recognising" the battery and shows "connection break". An open circuit, in other words.

Can I use the same BC6 charger to charge the Airtronics RDS8000 battery with battery inside the charger? Even I have a 110 V charger and no adapter, but I have an BC6 Equivalent charger.

http://www.nitroplanes.com/thac6smbalic.html

Cheers,
Vinay.

The default Airtronics battery is a NiCd, and should work with any delta peak charger.  Not sure about the connector required etc. 

RCDhamaka folks would know better, and I hope they will comment here.

So there a bad news for me! The charger socket in the Tx indeed not directly connected to the NiCd thru the on/off switch.  don't even think it is connected thru a Diode as I did not get a continuity by changing the polarity of the lead of the Multi Meter. There is a much larger circuitry in between  as the resistance on the positive wire was well around 1Mega ohm. I finally opened my TX and can clearly a good 3-4 cm of circuitry between the socket (first circle form left) and the connector receiving the Battery (2nd circle).

I also opened the charger box as its RIP anyway. There is hardly any circuitry there - just two diode forming a Half-Wave rectifier, some resisters to limit charge current and LED which double as current limiters ( they glow only when battery is connected).

Where to buy a Futaba charger ? I dont feel its safe now to charge my T7C using the balance charger as the residual charging circuitry inside the Tx may hinder the Del-Peak sensitivity and that the balance charger would be supplying way more of current, a real mess may happen.

May be I am just being paranoid, but the Futaba guy have not published any document on alternative method of charging the Tx Battery while in Tx.

Please Attached Pics are that of Futaba T7C 2.4GHz FAAST Tx. Other Tx models form Futaba and that of other brands may differ widely.

Based on your investigation, since the charge circuit is within the Transmitter it self, I think it should be safe to use any charger thats available in the market that has a bridge rectifier and has the same current capacity. I will open up my charger and see whats inside.

Same thing inside my RDS8K adapter. . It says that I can use the same adapter for charging receiver as well. Since there is no Delta peak on the receiver battery, Iam assuming there is no delta peak on the TX as well. Probably it just charges safely as the current is low, so that you can charge for 10 to 15 hrs and switch it off. Iam not sure as I have never wall charged till now since I don't have the 110 V adapter. I always remove the battery from the TX and charge with my AC6.

Quote from: ujjwaana on December 16, 2009, 02:41:54 AM
So there a bad news for me! The charger socket in the Tx indeed not directly connected to the NiCd thru the on/off switch. 

Hmmm ....  so what if there is additional circuitry ? Your complicated B6 charger is doing no worse than the simple Futaba charger (that died and you opened up). 

If you are concerned, just manually watch the peak voltage the first time you charge it (and always limit the current/charge rate).

Quotesome resisters to limit charge current and LED which double as current limiters

The resistors are to limit the charge current. The LEDs are ACROSS these resistors and turn on when charging due to the voltage drop across these.

@Anwar / Sushil
The only thing I fear is B6 giving more than necessary volt to Tx lead.

I would slightly discharge the battery and try to use B6 to charge the battery In-TX and would monitor Voltage/Current. I want to see how B6  'see' the voltage from battery (when there is circuit in between) and adjust the charge voltage. If things dont work, I am unsure whether to put an additional charge socket in the Tx and directly connect the battery or simply buy a new OEM Futaba charger.

What other thing I am considering is  that see what voltage the transformers delivers from secondary winding (Vinay's charger may help) and get a similar transformer/SMPS based adapter, and put the board from Futaba charger I smoked. This would be the safest, closest and cheapest solution.  Any LHS selling OEM Futaba/Airtronics Charger?  I have mailed Mr Sanjeev see what he replies.

I hope this discussion may help others in future falling into similar problem like mine.

-Ujjwal

Ujjwaana

The typical Futaba "wall" charger has a 0 - 6 -12 V secondary winding. Virtually any rewinder can do the job for you. Otherwise get a similar sized transformer with the above voltage rating at 150 - 200mA. Should work fine as it is not very critical. I would not recommend an SMPS type supply.

Quote from: ujjwaana on December 16, 2009, 04:09:25 PM
Any LHS selling OEM Futaba/Airtronics Charger?  I have mailed Mr Sanjeev see what he replies.
-Ujjwal

Hey Ujjwal you are great at getting information from the web, anyway RCD has the Airtronics/Sanwa Chargers for TX & RX and the best part it is 230V.

I don't think Sanjeev sells Futaba.