# Help - I've blown up my son's xmas ride on Jeep!



## svennard (Dec 29, 2016)

Hi all, I'm very much hoping I can get some assistance.

I bought the following 12v ride on jeep for my 3 year old as his main xmas present. Its a great bit of kit, but with the slow start function I found that it struggles to pull off if he stops on a slope.
I did some research (clearly not enough) and the general view was that I could simply run two 12v batteries in serial and put 24v through it. I did this battery mod last night and the internal controller went bang, 5 secs after switching it on..!

The car does stay on; the lights are still working, and I have forward and reverse motion (and it seems more powerful)

However, I appear to have lost the steering servo assistance when using the steering wheel itself. If using the remote controller I can go forward and back, and it does still steer left, but nothing happens when I try to steer right. The built in radio/ MP3 player is dead and horn no longer works.

I have taken the controller apart and I can see that one of the capacitors has exploded - on inspection, everything else looks intact - I have managed to get a replacement capacitor which I will fit tonight - I have now noticed that all of the capacitors and the two relays have 16v ratings. so I'm guessing that's why it went bang. If I'd have known, I wouldn't have done it...

I've no idea whether just changing this capacitor will restore it to how it was..

This is the vehicle - hhttp://kidselectriccars.co.uk/kids-...-jeep-with-suspension-p-597.html#.WGUzov4nwQE

Initially I just want to get it up and running back in its original 12v form. - I hoping that the fall back will be a new controller from the retailer - but I would still like to convert it to a 24v vehicle as this will be much more useable. 

I'd be really greatful of any help in restoring the car to its original state, plus any help with the most appropriate 24v controller that would work with this car. Alternatively, could I just upgrade the current circuit board with 24v (+) capacitors and relays?

Thanks


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## Coulomb (Apr 22, 2009)

svennard said:


> I have managed to get a replacement capacitor which I will fit tonight - I have now noticed that all of the capacitors and the two relays have 16v ratings. so I'm guessing that's why it went bang.


Yes, that's likely the reason for the failure. But the capacitor that exploded is likely a low-ESR unit (low Effective Series Resistance) which may look like any capacitor, but any capacitor won't necessarily do its job (at least not for long). So try and get a low ESR model if you can.


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## kennybobby (Aug 10, 2012)

without seeing the schematic it is difficult to say, but if you want to run at 24V, then at least double that to have margin, e.g. use a 50 V rating device.


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## svennard (Dec 29, 2016)

thanks for the replies. I've fitted the capacitor and the good news is that at the moment, I have full movement and control back, both in the car and on the remote - as for the type of capacitor, I'll have to see how long it lasts, but the rest of the controller seems ok.

On closer inspection, the radio has a separate 12v feed directly from the battery into its own small circuit board with 16v components which I'm guessing have been fried - so I have lost that, plus the start up sounds and the horn (which must be built into the radio unit circuit board)

I'll email the retailer to tomorrow and see if they can send me a new radio unit.

If I were to attempt the upgrade to 24v again (which I'd really like to) I'll need to have a 12v feed to the (new) radio unit and then a 24v feed to the controller, which both power up on start up.

Is there a recommended 24v controller with RC out there that I can retro fit? I'm struggling to find the right thing on the net.

It would need to control the twin motors to the rear wheels (forward/reverse), plus the single motor which only powers up when I operate the steering from the remote.

I can fit three batteries in the car, so I would have 2 x 12v 15ah in series, plus the original 12v 7ah just to power the radio and sound effects (which would need to be split when I switch the master on)

grateful of any suggestions on suitable controllers.

thanks


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## nucleus (May 18, 2012)

If you want it to have more oomph, build or buy a lithium battery for it. The voltage sag will be way less.


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## bigmotherwhale (Apr 15, 2011)

ushally those little ride on kids things have standard size motors similar to the ones used by remote control cars, get a brushless motor and controller and batteries from a hobby store it will go really fast. 

https://www.youtube.com/watch?v=41DBYxhOQOo


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