Gruber
HobbyMasters
M.L. Toys
KidsWheels
Gruber
HobbyMasters
M.L. Toys
KidsWheels
HobbyMasters M.L. Toys
Gruber
KidsWheels
Need new batteries? Going from 12V to 18V or 6V to 12V? Wiring Questions?
By Dwight
#149914
Fellow board members,

I recently purchased my 1st Power Wheels for my sons upcoming 3rd birthday. I plan on turning the Barbie Jeep Wrangler into something a little more custom. I've scoured the forums gathering as much information as I could but still am coming up empty on a few questions.

firstly, I've tried everything I could to see how old my battery is but all i'm seeing is something stamped into the battery itself of "1912PM2" and the model number being 00801-0638. The troubleshooting that i'm actually trying to do is to find out why, even after a nights charge, the power wheel doesn't go that fast. Could it be just an old battery, old charger, or something with the gearbox? I've taken the entire Power Wheels apart and both gearboxes seem to turn at the same speed when the pedal is pressed. However, when comparing how fast mine turn to ones i see online from a stock 12V battery, theirs is much faster.

Does this seems like a battery issue or possibly a gearbox issue? I just hope I'm not getting in over my head with trying to restore this old Barbie Jeep, and that any problems that i may have, i could easily find replacement parts for relatively cheap. Eventually i'll want to upgrade it to a 24V battery so that it has plenty of kick, but I know theres much more to that upgrade than just plug and play.


By Dwight
#149916
Update on battery condition:

After charging it most of the day the charger reads 14.3 volts and the battery is reading 11.8 volts. Do you guys think the battery is bad and could be what is causing the slower speeds and not holding a charge? From what I’m reading is 11.8 is kinda on the cusp
User avatar
By Hammer-fm
#149918
A good battery should be at least 12.8V after charging. A reading of11.8V is likely an indication of a bad cell.
By Dwight
#149919
Thank you for your reply! Could a battery that has a bad cell cause the gears to turn much slower than they should?
User avatar
By Hammer-fm
#149920
Yes, it will reduce the speed of the motors (no-load speed is proportional to applied voltage).

I have a few batteries with weak cells -- one cell holds about half as much as it should, so they charge up ok (12.8-12.9V), and will run fine for 10-20 minutes and then get really bad fairly suddenly. I also have a few with totally dead cells. Sometimes they fail in a way that allows them to still pass enough current through to run a vehicle -- albeit slower, and sometimes they fail "open" enough that as soon as you put any load on them they go to near-zero. It sounds like you have the former.

You can take additional measurements of the battery voltage while the vehicle is running (eg. prop the rear wheels up). If you have easy access to the motors you can measure the actual voltage at the motors. With a bad cell it will likely drop from 11.8 to ~10-10.5V when you try to run the motors even with just a light load like that. Compared with 12-12.5V under light load on a good battery, you've lost 20-25% voltage, and the same amount of speed, which is pretty noticeable.

Im doing this major overhaul of my daughter's PW E[…]

I may have one in the dream dazzler project I plan[…]

I am glad to read that you come up with outstandin[…]

4x4 12v circuit issue

wondering how do you like the sportrax. I'm saw so[…]

HobbyMasters Udemy Course