The Electric Buggy x 6Volts

CrankR · 26-07-2009, 09:55 PM

Hey guys need some battery input.

My 3y/o daughter loves her electric buggy to bits but it doesn't exactly rip her arms of the bars when she's going so am looking for a bit more power.

It's one of those cheap buggys from Big W or similar that cost stuff all and runs of a very ordinary 6v battery that doesn't hold charge for long but takes 8 hours to recharge.
It has recently died as i charged it for 24 hours by mistake.

Here are some pics of what i'm playing with.

Am not really up to speed with what it would take but i'm guessing one of you guys could give me some tips based on the pics that could help me get this thing moving better and for longer with the use of a better battery.

Is it possible?
Ta.

Oxa384 · 26-07-2009, 10:07 PM

hi ive just powered up my sons 6v four wheeler by wiring in another 6v battery(12v total),goes heaps faster (lifts front wheels when fully charged) also has worn the drive side wheel down too a slick!!!

joolz · 26-07-2009, 10:09 PM

Its only a 4.5Ah battery so rule of thumb is at 1amp drain it will last for 4.5 hrs, the buggy will drain atleast 10amps so do the maths. Increasing the voltage will make it go faster and will burn out the motor and or the controller. So just get a higher Ah rating battery but you will be restricted as you have a small place to fit it.

CrankR · 26-07-2009, 10:12 PM

2 batteries in series would give you a higher Ah wouldn't it?
2 in parrallel would give you 12V which would stuff the motor?

Oxa384 · 26-07-2009, 10:13 PM

heres a link to a youtube video on how to fit another battery.good luck!!
http://www.youtube.com/watch?v=qKQ4m...layer_embedded

also havnt burned out the motor yet (2 weeks)

EFPWR · 26-07-2009, 10:27 PM

Whilst adding a 2nd battery will speed it up, it will also shorten the life of the motor.

388cube_edxr8 · 27-07-2009, 12:43 AM

Replace the whole battery and running gear with a setup from one of those electric pushbike thingys. You might need a small wheelie bar but your daughter will love it and when the battery goes flat just replace it with a freshly charged one.

Still, she it 3 years old so it might be time for a new toy. Have you thought about a 49cc quadbike with an auto clutch? You can get tiny little kids ones that should be about the right size.

Then when it stops just put more petrol in problem solved.

mikestp · 27-07-2009, 12:50 AM

Quote:

Originally Posted by CrankR

2 batteries in series would give you a higher Ah wouldn't it?
2 in parrallel would give you 12V which would stuff the motor?

Thought it was the other way around

Blue Ice · 27-07-2009, 11:46 AM

Quote:

Originally Posted by mikestp

Thought it was the other way around

Same here. Pretty sure its, in series you get a combined higher voltage, paralleled you get a high current capacity.

downthetrack · 27-07-2009, 11:54 AM

Chuck in an optima 6volt battery, sealed unit, can be mounted any direction, not too big as its simply half an optima 12v battery. Downside it will probably be a bit pricey for what the toys worth (around $250 a few yrsback).

crusher · 27-07-2009, 02:09 PM

Bigger battery and brushless motor. That'll get it moving!

CrankR · 27-07-2009, 02:51 PM

U thinking 18v power tool motor or similar? Maybe a starter motor

tweeked · 27-07-2009, 03:10 PM

An 8V Battery is much better than a single Straight 6 battery

:

Sorry, couldn't help myself

Hotting up the kids electric car, i love it!

CrankR · 27-07-2009, 03:48 PM

Whooshca ;)

phillyc · 28-07-2009, 10:50 AM

Quote:

Originally Posted by CrankR

2 batteries in series would give you a higher Ah wouldn't it?
2 in parrallel would give you 12V which would stuff the motor?

Wrong. Its the other way around. Basic DC theory.

V = I*R where V is Volts, I is current and R is resistance.

DC Motors
RPM proportional to volts.
Torque proportional to current.

Parallel = increased Ampere hours.

Increasing Ah can mean slightly more 'punch' off the line. Batteries have an internal resistance which limits how much current can flow. In parallel it means there is more available maximum current. But at the current voltage most likely will not draw that new maximum.
Biggest benefit is increased Ah will allow it to run longer. Like putting a bigger fuel tank in.

Series = increased Volts.

Which will make it run faster. Higher revs due to voltage. Higher torque as more current will flow due to the higher voltage and same resistance. Its like supercharging a car!
But maybe burn out motor and controller as each are generally voltage rated for a particular lifespan.

So, grab a cheap cordless 18v or 14.4v drill and use it to mod the thing!!!!

phillyc · 28-07-2009, 10:53 AM

Quote:

Originally Posted by CrankR

U thinking 18v power tool motor or similar? Maybe a starter motor

Don't use a starter motor. Waaaay too powerful. Will most likely destroy any controller etc due to current draw.

18v power tool will be the go! Get batteries, motor, speed controller and charger all for a cheap price! Just bear in mind if you intend to use the original gearbox, it might not cope.

V8falcons · 28-07-2009, 09:25 PM

HA Ha ,I can relate to this,My daughter has a similar looking thing,and the 6volt battery might've been ok for when she was 3 but now 5 she(we) could see more power was needed,its a good thing I had a spare supercheap 18V cordless drill laying around, remove the old 6v push the terminals in the cordless battery and away she goes,now you could say its easily 3 times faster,but the plastic wheels are n ot up to the job and really need to be rubber. she was going through my cordless batteries fairly quick so she just got a 2 stroke quad for her birthday.
It all starts again

CrankR · 28-07-2009, 11:03 PM

Quote:

Originally Posted by phillyc

Don't use a starter motor. Waaaay too powerful. Will most likely destroy any controller etc due to current draw.

18v power tool will be the go! Get batteries, motor, speed controller and charger all for a cheap price! Just bear in mind if you intend to use the original gearbox, it might not cope.

Not exactly sure how i could use all this and make it work but it does sound fun.

Sort of like when the Aussie Top Gear boys ran that car off 4 battery drills i suppose....

CrankR · 28-07-2009, 11:06 PM

Quote:

Originally Posted by vctxr6ute

HA Ha ,I can relate to this,My daughter has a similar looking thing,and the 6volt battery might've been ok for when she was 3 but now 5 she(we) could see more power was needed,its a good thing I had a spare supercheap 18V cordless drill laying around, remove the old 6v push the terminals in the cordless battery and away she goes,now you could say its easily 3 times faster,but the plastic wheels are n ot up to the job and really need to be rubber. she was going through my cordless batteries fairly quick so she just got a 2 stroke quad for her birthday.
It all starts again

Ha HA, that sounds easy and fun

How did the electric motor stand up to the 18Volts?
Have a Black and Decker 18V drill with a spare battery i could use....doesn't harm the battery does it?
How long would a drill battery last but?

phillyc · 29-07-2009, 10:43 AM

Quote:

Originally Posted by CrankR

Have a Black and Decker 18V drill with a spare battery i could use....doesn't harm the battery does it?

No, it won't hurt the battery. The drill is a much harder load. But if the drill is a Lithium (Li etc description) use a multimeter to determine the outputs. Black and Decker will most likely be NiMH which only has the output terminals.

Quote:

Originally Posted by CrankR

How long would a drill battery last but?

There are two factors at play for run time one is Ampere Hr capacity and Watt Hr capacity.

* Ampere Hr capacity when comparing the same volts. So if the new battery is a 1800mAh battery that is 1.8Ah.

The original was 4.5Ah so 1.8/4.5 = 40% of the original run time.

* The other thing to look at is Watt hours. The original battery was 4.5Ah and 6 Volts. Multiply these two and you get 27Wh of capacity.

The new battery might be 1.8Ah and 18 Volts, equalling 32.4Wh of capacity. This means it has 20% more capacity.

So, the toy might last between 40% and 120% of the original run time.

There are a few things which will improve it though. Your daughter won't be on the power as long each time though, which will add some life to it. Battery design comes into it as well.

The original battery was 4.5Ah over a 20hr draw. So, the average draw was only 0.225Amps. When used in the application, the draw would be much higher. So in effect it could be rated as low as 3.0Ah over a 3hr draw, ie 1.0Amps for 3 hrs. The new battery might be 1.8Ah over 3hr draw. ie 0.6Amps for 3hrs.

The thing that will work against run time is that current draw is proportional to volts. So the maximum current draw could be up to 3 times. Current is proportional to torque which is why it will be so much more punchier!

Overall, i'd guestimate 2/3rds the run time.

Let us know how you go!