Daniel Eichhorn
In this post I will show you how to replace the batteries of an Anki Overdrive car either to increase the capacity or to fix a broken LiPo pack. But first a warning: this process will most likely void your warranty. Only do this if you know what your doing and on your own risk
As I wrote in this post I recently won a Anki Overdrive race track. It is a really cool toy and with its SDK a wonderful opportunity to play with it on a technical level. But I was quite disappointed when one of the cars seemed to have a broken LiPo battery: after a few warm up rounds I would get a battery warning and after a few more rounds the car would just stop working. I decided to open the car and to see what might be the problem. After all I had won the race track and it might be complicated to claim warranty without a receipt.
This article on ifixit about the older Anki Drive cars made me believe that it wasn’t too complicated to take the car apart. After all the Anki system got a repairability score of 8/10!
The result of the replacement is promising: the pimped car is not only working again but has even increased capacity, since the new LiPo has 100mAh instead of the original 70mAh!
The Battery
Replacement battery from ThingPulse. USE coupon SQUIX-ANKI during checkout to get a discount! You are supporting this blog.
Taking the car apart
You can see three screws if you turn the car upside down and look at the bottom. But only the biggest one in front of the car holds the hood in place. Unscrew it and you will be able to take the hood off. That was easy, right? Now to the slightly more complicated part. The PCB is hold in place by two tiny latches on each side of the car and two hooks at the back. Carefully release the latches and take out the PCB. Make sure that you don’t rip off the tiny wires at the back of the car which lead to the motors. Don’t try to completely remove the PCB from the black plastic part: the engines will stay connected with the motor during our little operation.
Now you can see the LiPo battery and the two forked light barriers which measure the motor speed. At this point I also realized that the LiPo pack had a soft bloated top which indicates that it was past its best time and degrading quickly (and also becoming more dangerous).
Replacing the battery
Now let’s replace the batteries! Heat up your soldering iron and carefully unsolder the red and the black wire connecting the battery with the PCB. You might want to use a desoldering wire or a desoldering pump to remove the excess solder. Also make sure that your wires don’t accidentally touch a part of the PCB. This might destroy the car! To avoid this wrap a tape around the end of the first wire.
Once you have removed the old battery we can continue to add the new one. Here we have a similar problem: you don’t want the wires to touch anything but the intended patches. Don’t forget that your battery is at least partially charged! Use tape or a third hand to keep the wires in place after removing the plug.
Closing it up
Now either use the double sided tape which held the old battery in place or make a “tape loop” and attach the battery to the PCB. This will help you to fit the PCB back into the chassis. Make sure that the end of the battery touches the optical sensor. When everything is nicely centered and the wires are in place slide the PCB into the hinge at the back of the car and make sure that the engine wires are placed in the slots. Now carefully move the PCB down below the two latches. My new battery is slightly bigger than the old one which causes the PCB to not completely sink into the chassis but this appears not to be a problem. Now use the screw to put the hood back in place.
First tests
Now put together a race track and use your car with another one to test the capacity of the new battery. The first time I put the car back together everything worked fine from the start. Then I took it apart again for this article and after that the car behaved as if it couldn’t read the race track anymore. I think that the forked light barrier might not have been in place properly or one of the cables obstructed the light. In that case open the car up again and make sure everything is in place. The second time everything worked fine.
I choose “Battle” mode to test the cars since they run until one of the cars wins enough points or the batteries run out. While the untampered car ran and eventually showed a “battery low” warning on the smart phone the pimped car continued to run for 20 more rounds without any sign of batter warning until the normal car just stopped. I know this is not a scientific experiment but it seems that the pimped car really profits from the increased capacity.
Summary
My little operation Save-the-car was a big success. The USD $50 car which was dead on arrival runs now longer than the stock cars for a cost of USD $3.- But be warned: I would only recommend this operation if your car is broken anyway or you are quite handy with a soldering iron. It is very easy to destroy it completely.
Please leave a comment with your experience if you also decided to do the replacement to encourage (or discourage;-)) other readers.
I have two cars i bought off ebay that have busted batteries. just ordered the batteries to give it ago. How quick was shipping from the vendor? Seems like it may take awhile.
Hi Jason. Banggood is quite reliable and for me it usually takes about 10-15 days until it arrives. Let me know here how it worked!
Finally got my batteries. One car works great. The other just runs…..lol. how did it behave when the optical sensor was affected?
Hello,
just wanted to say thanks for the blog. I successfully replaced a car battery, it now runs long and well. I agree that soldering is not easy.
any issues with the batteries being too big? I have one that seems fine but one that is slightly too big causing the wheel speed sensors to not read and the car to speed off uncontrollably….lol.
Any issue using the included charger to charge these new bigger batteries?
I ordered the parts from Banggood as proposed. I also managed to replace it, even though I was a bit struggling with the wires going from the board to the motors (they tend to break). However, after having put everything into place again I was happy because the led started flashing.
Unfortunately I am in some sort of stuck in a loop with the car. Everytime I’m connecting the car to my phone it wants to do a firmware update. After the update the car signalizes that it wants to do again an update, then again and again.
I don’t know what is wrong, especially as the car is not throwing any error. When I try a reset, the car starts to flash red, then it goes back to green.
Any idea what could be wrong?
Did you find a solution for this problem. I have a car with the same issue.
The wheelsensors need to be aligned, to do that the PCB board needs to be flat and not sticking out of the frame. i added a little plastic on top op the two square rubbers to keep some extra pressure on it.
What are the specs on the battery and if I were to order one what would I look for? I know it’s 75 Mah lithium, but I want to get the right size to fit.
I would also like to know the dimensions. Bangood is out of the part, so looking at other resources, but don’t know the actual dimensions. I guess I could just take mine apart now, but it still runs, just won’t hold a charge but for maybe one race.
i got mine from aliexpress, 5pcs for 11 bucks, delivered within a week.
100mah / 120mah 3.7v 20c For Cheerson CX10 CX-10 CX-10A RC Helicopter/RC quadcopter 3.7 V 100 mah Li-po battery 651620 5pcs/lot
http://s.aliexpress.com/6rIRziu2?fromSns=Copy to clipboard
I just purchased 2 batteries from this Ebay seller.
https://www.ebay.com/itm/3-7V-100mAh-Spare-Lipo-Battery-for-Cheerson-CX-10-RC-Airplane-Quadcopter-US/264106425376?_trksid=p2485497.m4902.l9144
hope to get them in a week, as they are US based. Then i will try my hand at this swap out.
hope i can get the Skull and Ground Shock cars working. i purchased them second hand on Ebay as well. the track is fine, but the cars will not run longer than one lap then they disconnect/lose power.
thanks for the guide on changing out the batteries. Anki seems to be very hush hush about sharing anything. So nice to find some info on repairing these cars.
great i had just successfully replaced to a 100mah battery . Tested and completed 45 laps with plenty of juice left.
The link to the battery doesn’t seem to work. Can you provide an updated link or another suitable replacement battery? Or the specs at least? Thanks.
Hello. Can someone tell me the exact part number or specs of the 75mAh LiPo battery I am supposed to get? There are many sizes out there.
Hi evereyone, i found a spare who works perfect, Revel 43971 Lipo-Accu, 3,7 V 100mAh, fits perfect for the anki Cars.
I just inserted a 100 mah battery into 2 cars and they don’t work at all. Just take off like a bat out of hell. Does not scan at all. One of my old batteries was good and I resoldered that in and it works fine. What the hell? How is this not working for me?
Hey Bret, I have the same issue. Did you figure it out?
Successfully repaired 2 display cars i got for a fiver which were basically DOA. I used a Husban Q4 Quadcopter 100mah battery which was actually smaller than the original battery. Got it on Ebay for those in the UK looking for quick delivery.
Another quick tip. If you want to reduce risk of frying the car, rather than unsoldering and resoldering the battery to the motherboard just cut the battery off (leaving cables attached to car) strip the ends on the old cables and the new battery cables and just solder them together (put some electrical tape around the joins after to avoid shorts if they come into contact with board). Much less risk of buring a chip or shorting the car that way.
Thanks for this! I just replaced 4 batteries (with 2 more to do) and will have 4 spares left over. It’s pretty simple with the right soldering iron. Just an FYI, the Supertrucks come with 90mah batteries and opposed to the 75mah batteries in the cars, but of course the same 100mah battery for the cars works great in the trucks (as should be expected). Cheers!
I know this post is old, but can you give me the exact model or specifications of the battery or an updated link, because I can’t find it anywhere online. The link in your post is outdated. I just bought this for my son, and I want it to last a long time!
I am also looking for batts for cars and trucks. I bought 2 tracks off Amazon at christmass for me and my grandson and all except 1 car had bad batteries. We need guidance as to where to get!
Hi everyone! I’m in Brazil, but I bought my set in USA through eBay. I got a little upset when GroundShock just performed one lap. So I found this post! After open both cars, I realized that both batteries were like blown. I got to find 3.7V 100mAh CX-10 batteries locally, and replaced in both cars. At first, GroundShock was not detecting the charger contacts when placed on it. I realized the PCB was not flat fitting in the frame. After fix it, everything goes OK, but after some laps, GroundShock did turned on after few seconds turned off by the small gray button, and so on. I didn’t check yet what could be happening. Anyway, thanks for this post!