RC India
Welcome Guest, please login or register.
 
Pages: [1]   Go Down
0 Members and 1 Guest are viewing this topic. Topic Tools Topic Tools 
Read
« on: October 04, 2014, 06:41:37 AM »
tcpip
Plane Lover
Active Member
**

Reputation Power: 1 
tcpip has no influence.
Offline Offline

City: bombay
State: Maharashtra
RC Skills: Beginner
Posts: 17
Join Date: Oct, 2014




 Hats Off Hi everyone. My first post here, and my first post anywhere in the RC model community. Smiley Fantastic forums --- have been a lurker for a few months.

I am 50 years old. I bought an RC helicopter from Mustafa's in Singapore last year for my seven-year-old son. Nose-tip to boom is about two and a half feet. Total beginner's model, co-axial contra-rotating props, three-channel 2.4 GHz RTF set.

This year, when I took it out to take my son flying, the battery is not holding charge. I removed the canopy (four self-threading screws) and found what looked like two AA-sized cells wrapped in a shrink-wrap opaque blue plastic "skin". It has two leads with two quite different connectors, one for powering the helicopter (two wires) and one for charging (three wires). The "skin" has the following stuff written on it.

Li-ion BQP232
18500 1100mAH 7.4V

So I hunted around, and discovered that when people talk of 7.4V, they mean 2S Lipo, whereas this battery clearly says Li-ion. Typical Li-ion 2S would be 6.6V. I was confused, but found some solution. The "18500" was the real help. Apparently, there are Li-ion batteries from Samsung and others which are in the AA format, are Li-ion, and have 3.7V rating. For example:

http://www.gr8alt.com/1100mah-imr-3-7v-18500-battery.html#.VC9GQa13Qjh

All these sites seem to be related to e-cigarettes.

I then found the following pack which seemed to be the perfect upgrade to my existing battery:

http://www.all-battery.com/SamsungLi-Ion18650_7.4V_2800mAhwithPCM-31444.aspx

It has a much higher mAh rating, so should give me at least twice the flying time, and I am not feeling too concerned about matching the "C" rating, because I suspect my park-flyer type helicopter won't have too much current requirement.

The battery has raw leads, so I will need some connectors to use it safely. The original battery had two leads, this one has just one. I guess the same leads will be used here both for charge and discharge. To handle this battery, I am thinking of buying a new charger. I found this one:

http://www.all-battery.com/universalsmartchargerforli-ionpolymerbatterypack37v-148v1-4cells.aspx

I will also need to replace the connectors at three places:

  • on the lead which comes out of the helo body, to receive power from the battery
  • on the lead from the new battery I am going to buy
  • on the lead from the charger which I will buy, so that it can charge the new battery
So, I read this article http://www.rchelicopterfun.com/rc-lipo-batteries.html and found this connector pack which seems to fit the bill:

http://www.hobbyking.com/hobbyking/store/__32960__EC3_Connectors_Male_Female_5_pairs_bag_.html

I have used a soldering iron on occasion, so I should be fine replacing the connectors.

Now for my questions:
  • Am I on the right track? This is a life-first for me, messing with RC equipment
  • Is there any replacement I can source from India anywhere? Would save me a lot of trouble

Thanks a lot for your guidance. As you can see, I need all the help I can get. And I have a very depressed son to bring back to his old chirpy self.  Grin
Logged
 

Read
« Reply #1 on: October 04, 2014, 07:37:51 AM »
ashok baijal
Plane Lover
Forum Hero
*****

Reputation Power: 7 
ashok baijal has no influence.
Offline Offline

City: Bangalore
State: Karnataka
RC Skills: Beginner
Posts: 595
Join Date: Oct, 2009



You can replace the battery with a 2S lipo which are available at local hobby stores in different capacities. This will need a lipo charger.

Alternately, you can replace with a 6cell nimh pack. These are quite robust and can be obtained in different sizes and capacity. When I was in Mumbai I would get my NiMh battery packs custom made from Prime Products, syntofine estate, goregaon east. These are quite robust. They have a website also. This will also need a different charger which if you are comfortable, you can make at home.
Logged
 

Read
« Reply #2 on: October 04, 2014, 10:19:16 AM »
ashimda
Plane Lover
Forum Hero
*****

Reputation Power: 8 
ashimda has no influence.
Offline Offline

City: kolkata
State: West Bengal
RC Skills: Beginner
Posts: 590
Join Date: Nov, 2013



Weigh the existing battery and replace with a 2S lipo of around same weight. The http://www.hobbyking.com/hobbyking/store/__7028__Turnigy_Accucel_6_50W_6A_Balancer_Charger_w_Accessories.html is a good charger and will serve you well in the future.
These chargers are available at local hobby stores in India.
Logged
 

Read
« Reply #3 on: October 04, 2014, 11:09:57 AM »
sundaram
FAN OF FPV FLYING, AERIAL PHOTOGRAPHY & MICRO RC
Plane Lover
Forum Hero

*****

Reputation Power: 38 
sundaram is working their way up.sundaram is working their way up.sundaram is working their way up.
Offline Offline

City: Gandhinagar
State: Gujarat
RC Skills: Advanced
Posts: 3407
Join Date: Nov, 2009



+1 to Ashim.

Just weigh the existing battery, replace with almost same weight Lipo 2S from LHS. You can replace the connectors at Heli side to the more compatible ones used with Lipo. So it will be easy for you to charge with Normal Charger.

On second thought what were you using to charge the supplied Lion? was it a balance charger? if so you can use the same charger. Just replace the connector at the new battery compatible to the existing charger with the connector removed from the old Lion battery.

Logged

 

Read
« Reply #4 on: October 07, 2014, 10:33:22 AM »
tcpip
Plane Lover
Active Member
**

Reputation Power: 1 
tcpip has no influence.
Offline Offline

City: bombay
State: Maharashtra
RC Skills: Beginner
Posts: 17
Join Date: Oct, 2014



Hi Ashim and Sundaram,

Thanks a lot. Sorry about the late response. I could not log in, because of some problem with my account. Anwar sorted it out.

I am confused about switching from Li-ion to LiPo. Doesn't this require a complete change of the craft's control electronics? I was under the impression that these are not interchangeable...

Sundaram, I suspect my current (Li-ion) charger is a balanced charger, because it has three leads to charge a 2S battery pack.

I was thinking of switching to an ordinary Li-ion battery (as described above) with just two leads, which would mean I would have to charge without balancing.

Logged
 

Read
« Reply #5 on: October 07, 2014, 10:36:08 AM »
tcpip
Plane Lover
Active Member
**

Reputation Power: 1 
tcpip has no influence.
Offline Offline

City: bombay
State: Maharashtra
RC Skills: Beginner
Posts: 17
Join Date: Oct, 2014



You can replace the battery with a 2S lipo which are available at local hobby stores in different capacities. This will need a lipo charger.
I was under the impression that the craft electronics need to be different to manage Li-ion and Lipo batteries? Are they freely interchangeable? This really opens up alternatives...
Logged
 

Read
« Reply #6 on: October 07, 2014, 10:58:44 AM »
sundaram
FAN OF FPV FLYING, AERIAL PHOTOGRAPHY & MICRO RC
Plane Lover
Forum Hero

*****

Reputation Power: 38 
sundaram is working their way up.sundaram is working their way up.sundaram is working their way up.
Offline Offline

City: Gandhinagar
State: Gujarat
RC Skills: Advanced
Posts: 3407
Join Date: Nov, 2009



Li-ion BQP232
18500 1100mAH 7.4V


As far as the heli circuit goes its not going to matter at all since the Lipo 2S is also with a similar voltage range  3.7 Volts to 4.2 volts fully charged. However some of the Lion has a fully charged voltage of 4.1 as against 4.2 of a Lipo. If that is the case the charger you have may not charge the lion to full capacity but will charge it to 95% only.

Most Balance chargers charge the Lion and Lipo battery in same category of selection in the menu IMHO that should be a reassuring confirmation that both are interchangeable. Its only Life batteries which are charged under different selection since thier final charged voltage is different from the Lipo/Lion.
Logged

 

Read
« Reply #7 on: October 07, 2014, 11:32:31 AM »
tcpip
Plane Lover
Active Member
**

Reputation Power: 1 
tcpip has no influence.
Offline Offline

City: bombay
State: Maharashtra
RC Skills: Beginner
Posts: 17
Join Date: Oct, 2014



Its only Life batteries which are charged under different selection since thier final charged voltage is different from the Lipo/Lion.
Great. This is very reassuring. Will look around for other options, then. Will these be good choices?

http://rcbazaar.com/products/1746-wolfpack-1800mah-25c-74v.aspx

http://rcbazaar.com/products/1747-wolfpack-3000mah-25c-74v.aspx

Logged
 

Read
« Reply #8 on: October 07, 2014, 11:34:15 AM »
tcpip
Plane Lover
Active Member
**

Reputation Power: 1 
tcpip has no influence.
Offline Offline

City: bombay
State: Maharashtra
RC Skills: Beginner
Posts: 17
Join Date: Oct, 2014



Both these RCBazaar items have a 2S structure, and two leads coming out -- one for balanced charging and one for discharge (the images are very low-res and unclear, but I am guessing). In that case, I may be able to get the benefit of balanced charging, compared to my earlier Li-ion choices I had seen in all-batteries.com.
Logged
 

Read
« Reply #9 on: October 07, 2014, 11:39:46 AM »
sundaram
FAN OF FPV FLYING, AERIAL PHOTOGRAPHY & MICRO RC
Plane Lover
Forum Hero

*****

Reputation Power: 38 
sundaram is working their way up.sundaram is working their way up.sundaram is working their way up.
Offline Offline

City: Gandhinagar
State: Gujarat
RC Skills: Advanced
Posts: 3407
Join Date: Nov, 2009



Keeping in view that you had a 1100mAH earlier, You need to take care that you are picking up Battery of similar weight so that your CG of Heli does not gets shifted majorly.

Even if you use heavy lipo Your Heli should be able to haul the additional weight and you should have room to shift Lipo to a new location to get CG correct.

As long as you can manage above you can pickup those lipos.
Logged

 

Read
« Reply #10 on: October 07, 2014, 12:56:18 PM »
tcpip
Plane Lover
Active Member
**

Reputation Power: 1 
tcpip has no influence.
Offline Offline

City: bombay
State: Maharashtra
RC Skills: Beginner
Posts: 17
Join Date: Oct, 2014



Great. Will do.

Any recommendations about a balanced charger for these?
Logged
 

Read
« Reply #11 on: October 07, 2014, 01:39:16 PM »
rcrcnitesh
Plane Lover
Forum Hero

*****

Reputation Power: 22 
rcrcnitesh barely matters.rcrcnitesh barely matters.
Offline Offline

City: Chennai
State: Tamil Nadu
RC Skills: Beginner
Posts: 2154
Join Date: Jul, 2013



Skyrc imax b6 copy or original from rcmumbai.com.
Btw why don't you look at rcdhamaka batteries.
Logged

Maker | Aeromodeller | Teenager
 

Read
« Reply #12 on: October 07, 2014, 02:27:09 PM »
tcpip
Plane Lover
Active Member
**

Reputation Power: 1 
tcpip has no influence.
Offline Offline

City: bombay
State: Maharashtra
RC Skills: Beginner
Posts: 17
Join Date: Oct, 2014



Skyrc imax b6 copy or original from rcmumbai.com.
Btw why don't you look at rcdhamaka batteries.
I have no idea about rcdhamaka... the first time I am hearing the name. Will definitely check them out. I had heard of rcbazaar from these forums, and the feedback was good, so I thought of them first.
Logged
 

Read
« Reply #13 on: October 22, 2014, 01:02:51 PM »
tcpip
Plane Lover
Active Member
**

Reputation Power: 1 
tcpip has no influence.
Offline Offline

City: bombay
State: Maharashtra
RC Skills: Beginner
Posts: 17
Join Date: Oct, 2014



Finished the surgery to the helicopter.

Used a LiPo 1800 mAh from RCbazaar instead of the original battery. This one is about 104 g whereas the original one was about 76 g in weight. It is also longer, so I can't place it in the cradle where the original battery was. Therefore I'm suspending this LiPo below the copter body using three cable ties. I will get self-adhesive hook-and-loop strips and do a better job sometime soon.

I also had to snip the original plug on the copter's power lead and replace it with Dean's Ultra connectors (called T-connectors quite often) connectors. Had some heatshrink tubing but it was too big in diameter, so the job was not as neat as I would have liked. Got the T connectors from RCMumbai

Needed a LiPo charger. Got a simple balanced charger from RCBazaar (costs less than Rs.1,000). It can charge 2S or 3S balanced LiPo batteries and is as simple as they come. It works.

Today, took out the bird and my son for the first trial flight. My son flew it happily. The battery has been placed a bit too far aft, and the CG has shifted a bit, so the helicopter drifts backwards a slight bit. More importantly, the helicopter has very limited inherent ability to penetrate a headwind, so it drifts to the edge of the field quite easily with even light wind. But the battery surgery has been successful.

Thanks for all the help. I did not have to import anything, and all your suggestions worked. AM thinking of getting a couple more batteries and the self-adhesive Velcro strips so that the batteries can be field-replaced, thus allowing for more flying time. Cheesy
Logged
 

Pages: [1]   Go Up
Jump to:  

Related Topics
Subject Started by Replies Views Last post
Using engine Oil to replace Suspention Oil
Cars
above the limt 12 9672 Last post April 27, 2022, 01:15:58 PM
by goncavid
replace / reinstalling a brushless motor shaft.. easily.. « 1 2  All »
Electric Power
roopeshkrishna 37 18998 Last post April 11, 2012, 01:06:37 PM
by roopeshkrishna
Replace the rx with a different make
Radios and Receivers
dheerajjuneja 5 3888 Last post July 19, 2012, 08:40:14 PM
by karandex
can we replace dji phantom's gps ?
Multirotors
ritz 1 1982 Last post June 04, 2014, 12:21:30 AM
by miginstruments
Want to replace 3.7v, 46000rpm motor in my fxd 68688
Chatter Zone
fzngagan 2 560 Last post January 12, 2023, 02:01:06 PM
by fzngagan