# batteries for a gocart???



## tomc000 (May 14, 2015)

hi

I'm looking into a racing go-cart. however I also want it to be able to go on the road to. could anyone give me a list of batteries that I could look into. would be great to know what my options are before I start building.

thanks


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## Sunking (Aug 10, 2009)

Well I have built two custom golf carts, and have helped quite a few others put together. My current cart can get up to around 50 mph if you got great big brass balls.

Universally the default chose is a Trojan battery, followed by US Battery. The Trojan T-105 is the standard in which all others are measured by. 

What I can teell you with certainty is you will never get above 25 to 30 mph with lead acid batteries and off the shelf golf cart parts. 

Here are your limitations.

To start with Weight and Space. You cannot put enough FLA batteries in a cart to get road speeds of any reasonable distance. By you the time you got enough batteries on the cart would break the frame and axle. However there is a work around if you have deep pockets, and you will need deep pockets to go fast.

The other challenge is golf carts were designed for 15 to 20 mph. The brakes cannot handle anything faster, The suspension is not designed to handle higher speeds. 

Next limitation is the motors, differential, and tire sizes do not allow for higher speed. You have a motor that is limited to around 5000 to 7000 RPM. You have a differential that is fixed. Anywhere from 8 to 20:1. So when coupled with the small tire size, fixed differential ratios, and even if the motor could make 7000 RPM's you only get to 25 to 30 mph.

So how do you get a golf cart to clock a 1/4 mile in 10 seconds and 118 mph? Simple you replace everything.

You buy a used cart, and only keep the frame and body. Throw everything else away, and custom build from the ground up.

You start with a lift kit,, wet disc brakes, all new suspension. About $1500. Then use a Lithium 48 to 140 volt battery, about another $2000 to $4000. Next is a good AC motor like a HPEV AC-9 or AC-15 with 550 amp controllers for $2700. Last is new larger wheels and tires. IO use 22-inch tire. 

Last is the big one, a transmission made to fit the motor. The least expensive option is to have a machine shop make you a Speed Gear which changes your ratio from say 14:1 to 4:1. Depends on how much torque and RPM's you motor can deliver. However the differential was never made for that much power. You can literally twist the drive axle and snap it. So most opt for a new heavy duty Differential Axle and those can cost several thousand dollars. Dana makes them.

So how fast do you want to go? To go fast cost big bucks. Most people just upgrade the DC motor, controller, lift kit, and larger wheels and tires. That will cost you around $3000 and get you 25 mph. Want to go 50mph? That will cost you over $10,000. 

FWIW here is the fastest golf cart on earth. 12.241 @ 118.76 mph


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## major (Apr 4, 2008)

tomc000 said:


> I'm looking into a *racing go-cart*. however I also want it to be able to go on the road to


*Racing go-cart *can cover a wide range of performance and budgets. Batteries and associated support systems are a big portion of the cost. If you intend to participate in organized race events or on existing tracks, you had better check the rules and regulations. If it just a fun cart, you can use about any type of battery.

I don't know of any place which allows racing go-carts on the public roads.

major


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## major (Apr 4, 2008)

You can find a number of go-cart or eKart build threads by searching this forum or look for examples on the EVAlbum or youTube.

http://www.diyelectriccar.com/forums/showthread.php/first-e-kart-electric-go-kart-142162.html


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## riba2233 (Apr 29, 2015)

major said:


> *Racing go-cart *can cover a wide range of performance and budgets. Batteries and associated support systems are a big portion of the cost. If you intend to participate in organized race events or on existing tracks, you had better check the rules and regulations. If it just a fun cart, you can use about any type of battery.
> 
> I don't know of any place which allows racing go-carts on the public roads.
> 
> major



There are street legal go-karts in Germany. 

Oh boy I would like to have that


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## Karter2 (Nov 17, 2011)

riba2233 said:


> There are street legal go-karts in Germany....


10 times more dangerous than riding a motorbike in a blindfold !
Too low to see the other traffic, and too low for the other traffic to see you.
Too wide to use like a bike
Too low to get over speed bumps or any slight raised obstacle.
Pot holes and bumps can throw you out of the seat
Wet roads mean a seat full of water.


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## riba2233 (Apr 29, 2015)

Yeah, good points, but it would still be a blast, I can only imagine faces of other people 

It would need some light that extrudes 2 meters high.


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## tomc000 (May 14, 2015)

I have been told its range has to be a 100 miles, not to worry about the speed, 30mph will be fine. the size of the cart I haven't decided yet. so having batteries running along each left and right side will be fine.


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## tomc000 (May 14, 2015)

I'm thinking of doing a similar car like the one on www.EVcapri.com 

http://www.evcapri.com/Kearons_EV_C...nsors_ourFormula_Green_prototype_racecar.html


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## tomc000 (May 14, 2015)

what batteries do you think I should go for?


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## bigmotherwhale (Apr 15, 2011)

tomc000 said:


> what batteries do you think I should go for?


The first choice would be Lithium - this will be expensive you will also need a BMS

Lipo or LiFePo4 

Lipo would be my first choice, 

the no 1 would be Nissan leaf cells or modules.
there are other electric cars at breakers also give it a try.

other sources
second hand sources for these are hybrid cars, electric cars laptop batteries and power tool batteries, no matter what you get you will need to make a matched pack so be careful what you buy or this could be difficult.



you can buy individual 18650 cells and make your own packs, vaping high drain batteries from a good manufacturer is a good bet - very high quality cells such as ICR18650-30A would be an excellent choice, number of cycles could go well into the thousands as will the price tag.

you could use a load hobby cells for rc cars, the good thing about these is that they are high discharge, but minus a few exceptions they aren't amazing quality so the number of discharge cycles are limited. 

you can buy LiFePo4 off ebay look for sinopoly 

If i was looking for a cheap pack, i would seriously consider a couple of prius NIMh packs, they are easily available in the UK from about £300 and they will perform better than lead acid. Charging these is difficult however look into it carefully before you buy, these should balance themselves so a bms is less critical. these are HV so you need to take precautions.


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## major (Apr 4, 2008)

*World Record????*



tomc000 said:


> I'm thinking of doing a similar car like the one on www.EVcapri.com


Sorry, but it bugs me when I see World Record LSR claims on a website like that. I was crewing for the Lightning electric motorcycle from 2009 thru 2011 and assaulted Bonneville each of those 3 years. The bike you see in my avitar was doing 165mph passes in 2009 chasing but not catching records in the APS alt fuel class (electric). In 2010 we set 8 FIA World records topping out at 173+mph. Kent Riches held the SCTA record at 176+mph. The Catavolt (website) bike claims 177kph (110mph) in 2010. Maybe enough for an Australian record, but far from a World Record. BTW, in 2011 the second generation Lightning electric motorcycle (2-wheeler, APS) was the first electric motorcycle to set a record above 200mph at 215.960mph, flying mile at Bonneville SCTA. Record still stands.

major


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## Karter2 (Nov 17, 2011)

tomc000 said:


> I'm thinking of doing a similar car like the one on www.EVcapri.com
> RL]


.?? Which car ?..the FVW ?.....why ? If you only need 30mph.
That is a very dated Site, ...not a good source of info for a new build.
..and what happened to the go kart idea ?


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## tomc000 (May 14, 2015)

my university project for this I'm told it needs a 100 mile range. the car's weight is 250kg.

your teacher said it we need to do all the theory before I'm allowed to start building.

the car has two 15KW motors with direct drive. speed isn't important only the range matters.

I know to go for theses type of battery 
http://www.everything-ev.com/index.php?main_page=index&cPath=65_128_135

but the question is how many?


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## tomc000 (May 14, 2015)

sorry made a mistake.

it has two 40kw motors


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## dougingraham (Jul 26, 2011)

tomc000 said:


> my university project for this I'm told it needs a 100 mile range. the car's weight is 250kg.


Using rules of thumb a 250kg (550 lbs) EV plus the weight of the driver would need ~75 wh per mile. So with 100 miles range required you would need a 7.5 kwh battery pack. You can make this pack a number of ways with cells from that company you provided a link to. How you make the pack depends on the voltage you need and controller/motor limitations. There will be a minimum voltage you want to go with for good motor operation. You could make this work with 40 AH cells by placing 59 in series. This gives you a nominal voltage of 189 volts. Using 60 AH cells would require 39 cells in series for a nominal voltage of 124.8. Using 90 ah cells would require 26 cells in series for a nominal voltage of 83 volts. This might be getting too low to give you a good torque band.

I would probably increase the number of cells in each case by at least 20 percent so you would get reasonable life from the pack. For example the 40 AH case of 59 cells would be increased to 71 cells. 71 cells of 40 ah would give a pack of 9.088 kwh and you should be able to make your range pretty easily with such a light EV even at speeds of 40mph assuming you can actually make that weight. 71 cells would weigh 113.6 kg (250 lbs) so is a significant portion of your weight budget.

Best Wishes!


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## Karter2 (Nov 17, 2011)

Some of those specs don't make much sense..
250kg vehicle (very light/small ?)..total weight inc battery ??
2x40kW motors = lots of power ..and weight ?
Primary objective is range , not speed. .?
I guess the objective is to force you to find the most efficient speed for those motors, and the batteries with the best energy density
Hint...probably.not those you proposed !


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## east2la (Nov 11, 2015)

Not a pro in the EV build community, but my current Kart goes about 58mph on Odyssey AGM batteries. And like it was mentioned here, you need Lipo or other battery setup for endurance. From what my builder had his setup, he was going for 1/4 mile records on it. I'm running a 144v DC motor on a Raptor 1200, currently driving at 500amps.


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