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. admin
    April 7, 2012 at 1:37 pm #

    Amos, It might work but there’s no protection circuitry on board so I wouldn’t recommend it. The S107 and it’s charger rely on the protection circuitry in the battery. You might run into trouble with over heating, etc with a battery like this. And these things are dangerous when they overheat (they can explode).

  2. admin
    April 8, 2012 at 1:19 pm #

    Hi Richard,

    Hmmm. Sounds like the receiver is dropping the signal. Try switching to a different channel on the transmitter.

  3. Fred
    June 3, 2012 at 8:54 pm #

    We followed your instructions and replaced the battery in our Syma 107. Now the question is what helicopter without a hard wired battery; in other words, a removable battery that change be charged and put back in, do you recommend. My wife wants to get me a better quality helcopter for FatherDay but without the hassles of battery hard wired cutting. Wnat do you recommend at a max of $125.00? Fred

  4. July 28, 2012 at 4:04 am #

    An excellent detailed explanation with image illustration. It can not get any better. Extremely useful for newbie trying to swap batteries on their Syma S107. GOOD JOB!

  5. Laurie
    September 23, 2012 at 12:44 pm #


    I have been reading about charging a battery and came across a post from 2010 that said the following:

    “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).”

    Is this true? I want to make sure I charge it the correct way and not overcharge it.


  6. admin
    September 24, 2012 at 6:56 am #

    Laurie, Well, Yes and no. The statement you read is correct but the battery itself contains the circuitry to prevent charging after a certain voltage. If you follow the instructions on this page and use one of the recommended replacement batteries, you will be okay. Many have done the same with no issues at all.

  7. admin
    September 24, 2012 at 7:52 am #

    Fred, Anything classified as Novice, intermediate, advanced or expert on this site will have a removable/replaceable battery. You can check out my recommendations on this page here on micro-helicopters.net.

  8. admin
    September 24, 2012 at 8:01 am #

    Variety, Thanks for the kind words. Glad you found it useful.

  9. Chris
    October 25, 2012 at 2:40 pm #

    How much does the stock battery weigh? why not wire 2 stock batteries in parallel to get 300 mAh depending on the weight or even 3 and stripping some of the pack itself to cut weight down which would give you 450mAh.

  10. admin
    November 1, 2012 at 8:53 am #


    The stock battery is 3.9g. Using 2 of these is going to be far too heavy. The battery pack is made of mylar and weighs next to nothing, so that won’t help much. In-fact, all it will do is make the components fall apart and run the risk of shorting. Even worse, you loose the covering over the lithium polymer compound that makes up the battery. This could be very dangerous because if the battery overcharges for some reason, it will swell and potentially off-gas or even explode (bad news if you’ve removed the covering).

  11. Jonathan
    December 17, 2012 at 12:43 pm #

    I followed the instructions and got the helicopter put back together without any problem. The problem now, however, is the same as before–the flight time hasn’t improved much at all. I changed to the 240 mAH battery. Has anyone else ran into this same problem? Maybe I just have a dud helicopter. Out of the box, though, it flew for much longer. Do you have any suggestions?

  12. admin
    December 21, 2012 at 6:13 am #

    Jonathan, Sorry you weren’t happy with the performance boost. What are the flight times you’re seeing since the upgrade? It’s hard to say if what you’re seeing is typical without some numbers. You could try again with a different battery or Helicopter, but you might also want to consider stepping up to a hobby grade heli.
    Good Luck,

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