Maker Pro
Maker Pro

Broken 12v electric quad

kidslovethequad

Jun 23, 2010
4
Joined
Jun 23, 2010
Messages
4
Can anyone help,

I have a 12v electric quad my kids have grown to love. It is in good all round condition but has stopped working properly. Last running good last september then stored in shed until a month or two ago and then running poorly. At first I thought was a battery fault so bought an optimiser, the battery is good, taking a full charge and giving out 11.8v. It has seemingly simple electronice. The accelerator is a click down pedal switch and all i can see between the battery and the motors are a couple of little black boxes?? About an inch square!! It is running, just only at around 2 kph as opposed to around 12 kph and seems sluggish.

My little lad is gutted, does anyone have any suggestions on how I may repair the fault.

Many thanks,

Liam.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
The battery sounds discharged, or has a dead cell. (presuming it's a lead acid battery)

Fully charged, I'd expect to see a voltage around 13.5 volts.

What is the voltage across the battery when the motor is running? My guess is that it falls very low.

Do you have another battery to replace it with (even temporarily) to see if that fixes it?
 

kidslovethequad

Jun 23, 2010
4
Joined
Jun 23, 2010
Messages
4
Thanks Steve,

Ok, The batteries are 2 x 6v 10 ah. Charger goes to black on one battery and red on the other. A link cables connect the other two terminals. I get 7v across eath battery and 13v when linked etc. I Have charged each battery for 24hrs with a battery optimiser for motorcycle batteries etc. They each had an imput charge around 8v and 0.62amps! Put the kids on tonight and all seemed well for, ahem, about 30 seconds then it just slowed and eventually stopped. The batteries are sealed lead acid. Am trying to use the original charger tonight which seems to output 19v and according to the label 1200ma!! I think originally the batteries were asleep over the long winter and am hoping the optimiser has recovered them enough for the proper charger to take over?? Any more thoughts?? Thankyou
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
SLA batteries (lead acid batteries in general), if left discharged for any period will die a horrible death.

If the batteries were not charged when the car was put away, it's almost certain that they're going to need replacement.

I would recommend that you ensure that they are fully charged before being put into storage and that you charge them every 6 months (or even more often). Leaving them in freezing conditions is not good, but is far worse if they are discharged. (freezing may or may not be an issue wherever you live)
 

kidslovethequad

Jun 23, 2010
4
Joined
Jun 23, 2010
Messages
4
Thanks Steve,

Ok, batteries still not retaining charge for more than 30 seconds so as you said, knackered!!

I will order some more but, instead of 2 x 6v 10 ah units, would i be better with 1 x 12v unit?? Also, is the greater the ah the longer is the run time??

Thankyou,

Liam.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
In general, higher Ah = longer run time. 1 x 12v battery rather than 2 x 6V is fine. The issue will be whether they can be physically fitted in the car :)

Remember that the currents available from these batteries are potentially dangerous. Ensure it is not possible for the battery terminals to short to a metal surface or for a child to stick something metal in there and short the batteries. The end result could be sparks, flames, and a badly burnt child. (this is true even from quite small lead acid batteries. Better to be safe than sorry.
 

kidslovethequad

Jun 23, 2010
4
Joined
Jun 23, 2010
Messages
4
Hi Steve,

In place of the two 6V 10ah units i can fit a 12V 12ah unit. Which would be best, ie why was the car supplied with 2 x 6V?? What would you fit?? Longer run time is priority with my two little ones!!

Thanks
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
I can't comment as to why they used 2 x 6V batteries (maybe they got them cheap?)

A 12V 12Ah should last approx 20% longer than 2x 6V 10Ah. You also only have one battery to charge :)
 
Top