Easy 7 Step Syma S107 Battery Replacement Instructions

The Syma S107 battery replacement is easy to do. Even so, many people are afraid to attempt it because they are worried about damaging something. To make it easier, I’m going to demonstrate the exact steps you need to take in order to replace the battery. Hopefully this will give you the confidence you need to tackle this project and get more use out of your Syma S107. Before we get into the specific steps, here’s some background…

Why replace the battery?

There are only a couple of reasons to change the battery in an S107.

  1. The battery is not holding its charge as long as it used to. The symptoms of this might be short flight time (less than 2min), inability to fly very high, or taking too long to charge (more than 1hr)
  2. You want to get better flight and performance compared to the stock Syma S107 battery.

Selecting a replacement battery

Once you decide to replace your s107 battery, the next thing you’ll need to do is select your battery.

Obviously, the safest approach is to drop in a direct replacement for the original battery to ensure that everything is compatible. To do this you’ll need to find a battery with equivalent specs to the S107 battery. Click here to buy a stock replacement battery with equivalent specs online.

If your goal is to improve flight time over and above the original S107 battery, you’ll need to find a 3.7V lipo with significantly more than 150mAh capacity. The trick is, you need something that doesn’t weigh much more than the original battery (3.9g). If it weighs too much, it’s going to be difficult to keep the helicopter balanced without adding weight to the tail. If you start going down this slippery slope, any gain in battery capacity could be outweighed by the extra weight of the battery. If you want to give it a try, check out this 5.6g 240mAH battery.

Update: I have purchased both of the batteries above with excellent results. In fact, I was able to achieve much better flight times with both of the above batteries compared to how it performed out of the box. To put it into perspective, I did some time trials by charging the battery then hovering the heli until the battery could no longer hold it at about 4 feet. I stopped the timer as soon as it dropped below that at full throttle. The Results?

  • Stock 150mAH Battery: 8 Minutes 17 Seconds
  • 240mAH Battery: 9 Minutes 51 Seconds.

I also want to make it clear that there are NO compatibility issues with the batteries specified above. There have been comments and emails to indicate that the upgraded battery will not work with the S107. These claims are false. I have verified the circuits both in the charger and on the battery. My 240mAH battery has gone through many charge cycles already and still performs great. Anyway, lets get on with it…

Syma S107 battery replacement Instructions

Okay. So now that we’ve got the background out of the way, lets get into the details of how to perform the swap.

Step 1: Remove the screw from each side of the canopy

Step 2: Remove the Canopy from the Helicopter

Step 3: Disconnect the Canopy from the Helicopter and set it aside

Step 4: Cut the red and black wires and remove the battery (be sure to leave some extra length for splicing)

Step 5: Attach the new battery by splicing (twisting) the red and black wires together, then cover both with heat shrink or electrical tape

Step 6: Adjust the balance by moving the battery position back and forth until it balances. I used a DVD case but whatever you use, make sure that the mast for the main rotors lines up with the center of the object. Otherwise, the balance will be off.

Step 7: Connect and reinstall the canopy

Once again, if you need a replacement battery, I got my 150mAH stock replacement battery here and my 240mAH upgrade battery here.

And that’s it! Your Syma S107 Battery is now ready for charging. Nothing left to do but sit back and enjoy the improved performance and longer flight times.



62 Responses to “Easy 7 Step Syma S107 Battery Replacement Instructions”

  1. Morris
    October 4, 2010 at 11:38 pm #

    The Li-poly that comes with the S107 has an internal charging circuit – a small PCB that stops the cell charging once it has reached full charge (About 4.25 Volts) and it may also regulate the charging current (I didn’t check that).

    The Yellow USB cable is *not* a Li-Poly charger. It has a 1 Ohm resistor (marked 1R0) and a diode (marked D/) in series from the USB 5 Volt supply. So it will overcharge a cell and ruin it. The chip inside the USB cable (LM358) is only there to light the LED when it detects no current being drawn (because the Li-Poly circuit is turned off and drawing zero current).

    Options:

    1. replace the cell with one that also has an internal charging circuit.

    2. remove the internal circuit from the standard 150mA cell, and put it into your larger cell.

    3. Use a regulated Li-ion charger when charging the cell (either through a dedicated connector to the battery, or through the charging socket on the helicopter e.g. cut off the yellow cable from the USB “charger” and hack that onto your charger).

  2. Carlos
    March 13, 2011 at 8:24 am #

    I want to know how long flies with battery 240 mah

  3. admin
    March 22, 2011 at 8:05 am #

    I haven’t done any time trials yet but I would expect it to be around 4-7 minutes. Battery life is hard to predict and usually depends on a lot of factors.

  4. Gary
    March 27, 2011 at 5:05 am #

    I need to replace the battery in my s107 but the wire connection seems a little tricky. Can you connect the battery wires to the plastic plug and then just plug it back in instead of splicing the wires? That seems easier. Thanks.

  5. admin
    March 28, 2011 at 8:22 am #

    No. Unfortunately you need to connect it to the main board. They would prefer you just buy a new helicopter.

  6. Mike
    December 5, 2011 at 11:30 pm #

    Just wondering. If i were to connect two batteries together, would the battery charger charge both batteries? I know the chopper has has the lift ability. The extra battery could be electrical tapped to the bottom of the chasy. Is it parallel or series to in crease the amp hrs? please e-mail me back, thanks

  7. admin
    December 6, 2011 at 7:07 am #

    Mike,
    The charger should handle it but I’m not sure if both (or either) battery would charge properly. I wouldn’t recommend it. If you want more capacity why not just buy a bigger battery? They’re cheap.
    Go ahead and give it a try if you want though. You would need to wire them in parallel (don’t do series).

  8. David Sutton
    December 20, 2011 at 2:43 am #

    I wonder if you could put male & female pins on the wires to make the battery easily replacable.

    It seems to me, if it can be done, the ideal is to buy multiple batteries and then just swap them out as needed.

    The batteries have time to cool & charge. You can keep playing indefinitely, depending on how many batteries you can simultaneously charge.

    Would the pins throw the flight off?

  9. David Sutton
    December 20, 2011 at 2:47 am #

    A question:
    The first comment above was unclear.

    If, using the *stock* battery that comes with the S107G, I charge it with the USB port, can I accidentally overcharge and ruin the battery?

  10. admin
    December 21, 2011 at 10:32 pm #

    David,

    I’ll address both of your questions here.
    1. Sure you could use a connector to make replacing the battery easy. One idea I’ve even thought about is removing the LED light at the front of the helicopter and using that connector for the battery. This will make the battery easier to replace and eliminate a tiny bit of extra battery load.
    2. You won’t overcharge the battery because there is a built in circuit that stops the charging cycle once it reaches a certain voltage.

  11. juan ramirez
    January 7, 2012 at 11:41 pm #

    witch batterie can i buy better that that one

  12. Bryan
    January 10, 2012 at 1:48 am #

    I am going to buy the 240mah battery so I can fly my syma longer
    But what is parallel and series mean? What’s the difference

  13. admin
    January 10, 2012 at 7:07 am #

    Juan, the batteries mentioned in the article above are what I recommend.

  14. admin
    January 10, 2012 at 7:12 am #

    Bryan,

    parallel and series refers to how the two or more batteries would be connected together (best to stick to one battery though).

    With parallel, you wire all the red wires together and all the black wires together.

    With series, you daisy chain the batteries together. Meaning you connect the black of one battery to the red of another. You will then be left with 2 unconnected wires, a black from one battery and a red from the other. You use those unconnected wires to wire into the helicopter as if it was a single battery.

  15. Larry
    January 10, 2012 at 11:54 pm #

    My flight time is beginning to get short on my S110G so I’d like to replace the battery. Since the S110 is such a small bird I don’t know if it would benefit from a larger battery or if I will need to stay with the stock battery.

    Have you tried any battery upgrades to the Syma S110G?

  16. admin
    January 11, 2012 at 7:17 am #

    Larry,

    I haven’t played with the S110G but the same holds true as for the S107 or any other helicopter. It’s a trade off between capacity and weight. You can try and go with a larger battery, but find one with as many extra mAh as possible while keeping the weight as low as possible. Then give it a try and see how it flys.

  17. John
    January 12, 2012 at 3:28 pm #

    I have a S107 that does not charge the onboard heli battery using the USB connector or the RC handset. Does the heli battery needs the be replace?

  18. Chris
    January 17, 2012 at 9:52 pm #

    Great write up!

    One quick question…how much longer does it take to charge the 240mah battery?

    Thanks,
    Chris

  19. admin
    January 18, 2012 at 9:45 pm #

    John,

    It might. But first, are you sure it is connecting properly? The light on the charging cable (usb end) should glow when you plug it in to a USB port and turn off when you plug in the helicopter. Similarly, the LED should be green when you turn on the transmitter and red when you plug in the helicopter. When you try to use the helicopter does it spin up? If it doesn’t spin up at all or the lights don’t behave as they should, it’s probably a loose connection somewhere. If it seems to charge okay but just doesn’t have enough power when you try to fly it, it might be the battery.

  20. Ron
    January 21, 2012 at 4:13 pm #

    I purchased a battery for the S107 and was using the 7 steps to install by splicing the wires from the battery to the wires (red and black) from the heli. Everything was going great then while replacing the canopy the wires soldered to their positions on the heli came loose. I have no idea where they were attached. Can you advise? There are six possible solder points where wires are soldered – looking in from the front left to right:

    1. red wire attached
    2. blue wire attached
    3. red wire attached
    4. black wire attached
    5. blue wire attached 6. no wire attached

    I’m thinking 1 and 6 may be the correct ones because 1 has a larger solder point and 6 has not wires attached to it and possibly the black one from the battery may attach there with the red one from the battery to the no. 1 which already has a red wire attached to it.

    Also the canopy has no connection to release the canopy so I’m wondering how old this heli is?
    Thanks.

  21. admin
    January 22, 2012 at 3:23 pm #

    Ron,
    If your’e missing the connector between the board and the LED, I’m questioning whether yours is an authentic S107.
    I’ll tell you where mine are attached but your helicopter may be different.

    Although there are 6 solder points across the front of the board, none of them are attached to the canopy LED. There is a another solder point right between the row of 6 that you mentioned inbetween positions 5 and 6 when counting from left to right. That is where the black wire goes. The red wire connects a little further back just behind position 3 (adjacent to the on/off switch).

    I hope that helps.
    Good luck.

  22. Ron
    January 22, 2012 at 6:12 pm #

    Thanks. I’ll see if I can locate the places you suggested. It may be a fake since the connector to the LED is there. The wires go directly to the LED in the underside of the nose of the canopy. Nothing like a connector present. A yellow and a white wire comes from the LED and the white one runs beneath the board on the right side, below point #6 while the yellow one runs underneath on the left side, below point #1. I can’t tell whether either one is attached to the solder point above it though. You said that they shouldn’t be – I just can’t see.

    Are you saying the battery wires (red or black)should not be soldered to any of the points 1 through 6 across the front of the frame then? And that they are to be attached to points behind these 1-6 further into the frame? I can’t say that I can get to them if that is the case. Using a magnifying glass I don’t see any solder points behind them.

    No. 1 point is just on the inside of the frame to the right of the on/off switch looking in from the front. That point has a huge mound of solder with a red wire attached to it. Underneath that one is where the white wire from the LED routes but can’t tell if it attaches to the point #1.

    I bought this through Amazon so I guess there was no way to tell if it was a genuine S107. The only sign I had read about was the warning decal on the top rotors. I read one comment from a person on RC Groups.com about batteries having snap on connectors to remove them but in this case it will be a case of having to go through this exercise each time a battery is replaced. Not sure if it is worth all the effort particularly if I can’t be sure it is an authentic heli anyway.
    Thanks for all the help.

  23. Ron
    January 22, 2012 at 6:28 pm #

    I did a google search on genuine vs fake s107’s and according to some photos I found this one appears to be authentic. Even though it doesn’t have a connector on the LED wires in the canopy. Don’t know how accurate this all is. I’m really new on this sort of thing.

  24. admin
    January 22, 2012 at 9:18 pm #

    Ron,

    The connections behind the row of 6 that I’m talking about are from the LED in the canopy. Your original comment sounded like those were the wires that came loose. If you’re looking for the battery connections, my S107s have the red wire connected to the far left position and the black to the far right.

    Hope that helps.

  25. Ron
    January 22, 2012 at 11:06 pm #

    THANK YOU! You just solved my dilemma. The two battery leads (red and black) are the ones which came off and are the ones I indeed need to re-solder.

    In the beginning, in order to have plenty of wire,I had snipped the original two leads from the old battery right up close to it, leaving them soldered in place at the other end. Then spliced the leads from the new battery to them and covered with the electrician tape. Upon replacing the canopy one of the tiny screws fell inside the heli. While trying to find and remove it, the wires still connected to the solder points, came off.

    What you mentioned regarding the red wire to the far left and black wire to the far right is exactly what I needed to know. Thanks again.

  26. Ron
    January 24, 2012 at 11:17 pm #

    I was able to re-solder the red and black battery leads back in place following your instructions. The on-board lights work so I suppose the operation was a success as far as the battery is concerned. But after charging the battery on its maiden flight it would not take off nor would the tail rotor spin. Also the lower main rotor rotates very slowly while the upper one rotates as it should. Noticing that there are three motors and three rotor sets, I surmise that maybe two of the three are shot. Maybe some wires touched / solder bridged or were damaged during the soldering? Have a feeling that this s107 is beyond help at this point.

    Also, do you know if the Syma S107 and the heli offered by a company named Swann are one and the same? I purchased two of the latter for Christmas for my grandkids only to have to return them. Holding them side by side they have a lot of similarities to me, right down to holes in the frame etc.
    Thanks.
    Ron

  27. Sabyx5
    January 26, 2012 at 11:11 pm #

    Hi
    I have one that looks exactly like a Syma s107 like yours in pic but is from Votilation. I stupidly charged it using my phone charger. It worked great the first time ,taking oly 15-20 min to fully charge. Then on second charge i left it accidentally too long 40 min, and now nothing works when turn heli switch To ON. Que passa? Did battery burn up, or all circuits fried? Pls help!

  28. admin
    January 27, 2012 at 6:49 am #

    Ron,

    I’d check to make sure that the tail rotor wires are still connected and have not broken. As for the slow lower rotor set, check to make sure that all gears and shaft are free of debris and hair. It doens’t take much to cripple little heli. Also make sure that the gears engage properly and move freely.

    I’m not familiar with Swann. There are so many coppies and re-brands of the S107 out there that it’s impossible to keep up with them all. Thats why I typically recommend people stick with a genuine S107 from a reputable dealer. Many of the re-brands and coppies are of good quality but many aren’t.

  29. admin
    January 27, 2012 at 6:56 am #

    Sabyx5,

    Probably fried the battery. Careful cause those things are dangerous and they can explode! A genuine S107 would prevent the battery from overcharging. Most likely yours is a clone that didn’t bother to copy the safety features. You could replace the battery but you might just end up in the same boat again.

  30. Dave
    January 29, 2012 at 3:27 pm #

    Good stuff. I’ve been charging my s107 with an AC adapptor from a small camera. It says:
    DC5V 1000mA
    Worked fine for weeks, then beagn to lose power and finally, not fly. Fried the battery?

    Thanks, Dave

  31. dave
    January 30, 2012 at 12:35 pm #

    Battery is in. No sweat. Now to replace inner shaft. (broke very top plastic piece off) How to do it? Thanks

  32. dave
    January 30, 2012 at 1:04 pm #

    Replc’d battery and all’s well. Broke top of inner shaft plastic off. How do you replace inner shaft? Assuming you have to replace shaft since plastic on top is not removeable/replaceable?

  33. Sabyx5
    February 4, 2012 at 2:28 am #

    I ordered a new battery from your recommended website. Hooked it back up as per your instruction and now it works like a charm!
    Could have done without your help, thanks very much!!!

  34. Sabyx5
    February 4, 2012 at 2:38 am #

    “Could NOT have done it without our help”, that is
    Thx again!!

  35. Philip
    February 7, 2012 at 5:06 am #

    Hi – I love my S107G but recently the lower pair of blades has stopped spinning and therefore will no longer take off or work properly. Do you think the motor that powers the lower set is broken? Thanks for any advice.

  36. admin
    February 7, 2012 at 10:10 am #

    Dave, Sorry for the late relply. Glad you managed to get the battery replaced. It was probably just worn out. An over sized adapter shouldn’t cause a problem as long as the voltage is 5Vdc. Some have said that you can find replacement plastic for the inner shaft but it’s not a part that syma makes available. I’d just buy a new inner shaft. to remove it just undo the linkages and pull it out. You have to pull pretty hard. Check out youtube, there are some videos that show this.

  37. admin
    February 7, 2012 at 10:12 am #

    Philip,

    That’s possible. I’d first check that all your gears are still aligned and engaging properly. Also check for any debris or hair that might be wrapped around the shaft, motor, gears etc. This can sometimes cause the blades to stall. If everything seems good then go ahead and try replacing the motor. Good luck.

  38. Richard
    February 10, 2012 at 4:43 pm #

    Hi I have just got my first 107g but have a problem. When I throttle up the blades start to spin then cuts out this happens several times before full power is obtained to take off. I have tried using another tx and the same symptoms occur. The light on the cicuit board is sometimes flashing and sometimes solid, would this mean the tx is not binding properly with the rx. It also drops out sometimes during flight when only flown for about 60 seconds. The area i fly in is a small room and should be well within the infrared range. Is this a case of return to the shop for a replacement or is there an easy fix, your comments would be valued.
    Regards

    Richard

  39. graeme
    February 12, 2012 at 5:56 am #

    The above instruction was very good. However, I would like to know where the red and black wires are supposed to be connected to the circuit board as mine have come off and I cannot see where the came off.
    Can you show by diagram

    Thanks

    Gb

  40. gio
    February 13, 2012 at 6:08 pm #

    Hey my s107 worked great for a couple months, then it sat unused for nearly 9 months. Ever since it sat, it doesn’t perform as well. It loses power pretty quickly (can’t keep off the ground more than 2 minutes or so) and just isn’t as snappy and responsive as it used to be. Is this likely to be a battery issue?

    Thanks!

  41. Matt
    February 20, 2012 at 5:59 pm #

    Heli was working great – power cut off mid flight, now when I connect to either the USB or controller nothig happens, USB light stays on or controller light stays green, assuming it is the battery

    Dave – if the shaft is OK you can just replace the shaft head, I jujst did this, easier than replacing the whole shaft.

  42. admin
    February 21, 2012 at 7:22 am #

    Richard,

    Sounds like your heli is having trouble receiving the signal from the transmitter. Make sure you have line-of-sight (no obstructions between the helicopter and the transmitter). You can also check to make sure that the receiver (little black rectangle thing that sticks out the back of the heli) is soldered properly to the board. Good Luck.

  43. admin
    February 21, 2012 at 7:25 am #

    Hi Graeme,

    Sorry I don’t have a diagram to show you right now but if you take off the nose cone and look at the front of the circuit board you will see a row of solder points. The one on the far left is where the red wire connects to and the one on the far left is where the black wire connects to. Good luck.

  44. admin
    February 21, 2012 at 7:26 am #

    gio,

    Yes indeed. Your battery is no longer holding its charge. The above instructions should help you fix that.

  45. admin
    February 21, 2012 at 7:30 am #

    Matt,

    Sounds like a wire may have come loose, could be from the battery or something else. I’d pull off the nose cone and check it out.

  46. wade
    February 21, 2012 at 10:13 pm #

    Hello, I just bought one of the choppers in san Diego and I love it!! I flew it several times on my visit there. The problem is when I returned home to mammoth lakes (9000) ft above sea level, the chopper just will hover about 2inches off the ground. It clearly does not have enough lift. Any suggestions?? Thanks.

  47. admin
    February 22, 2012 at 6:43 am #

    Wade,

    Make sure the shafts and gears are clean and free from debris and hair. A tiny piece of hair wrapped around a shaft can cause enough drag that the blades won’t spin fast enough to lift off the ground. This is the most common reason that these helicopters don’t take off. Make sure that the blades rotate freely. If everything is clear, make sure the battery is fully charged, if it is, you might need to replace the battery. Good luck.

  48. March 11, 2012 at 7:31 pm #

    Do you think this battery would work with the same charger and everything if it was just swapped into the helicopter? I know it would take some modification to get it to fit.

    http://www.all-battery.com/polymerli-ionbattery37v300mah561540.aspx

  49. Richard Castillo
    March 19, 2012 at 8:40 pm #

    Hello,

    I am so glad to see so many questions being answered. I have one of these and it does not work. It was a great little copter while it did, but suddenly stopped working.
    The battery is taking the charge from the remote, remote light turns green after full charge, the LED lights up front blink. My green reciever light blinks at first, then stays green, acknowledging the link, but nothing happens, at all. There is no resistance to the blades, gears look good, no problems at all. Even the reciever (black box at end of copter) is solderd good and appears to be in good condition.
    I have maybe one hour flight time with it.
    Any suggestions? Can I re-set the tx? Love the copter, even buying one as a gift to my nephew, but hurts that this one is broken ;(

  50. Eric
    March 23, 2012 at 3:38 pm #

    Great site. Been flying the S107G for a few days now…and no issues yet. I’ve tried to allow ample cooling between uses and chargings. Hopefully this will help. Assuming I’ll need a battery swap in the future, though, I’ve bookmarked this page. Thanks in advance!

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