sleeper powerwheels build, thoughts on battery

[isthatvinny]

this is my sleeper powerwheels build, it currently uses a kelly KVD7215ND controller, MY1020 3000w motor and a 5ah 60v SLA pack. the battery is awful i know, but i bought the current motor and controller off marketplace and guy gave me the battery, im cheap and impatient so its in there, for now, just to get it going.

so first obvious upgrade is battery, ive priced out some large batteries with thoughts of the QS165 motor and larger kelly in the future and the largest i can fit i one space is a 60v 75ah, 120a continuous battery from Amorge that weighs about 40lbs using 18650 batteries. this is a decent choice but unfortunately with my obvious size limitations that would have to be mounted rear of the axle along with the large QS motor. yes i could go smaller in size of battery but were out here doing hoodrat shit with my friends and need the extra sauce in the tank for quick getaways. also with the kind of power going into this id only do wheelies.

this is a lot of rear weight along with me sitting almost directly atop the rear axle. id like to try to disperse the weight for better handling especially when the cart has drift rings on it. the cart has a full steering rack and pinion not a pitman arm so it gets great angle and the hand over hand steering feel with tiny powerwheels steering wheel is hilariously fun.

other smaller areas around the cart include 3 inch tall space full 16 inch width of frame under the seat from axle to steering collum, under and forward of the steering collum between my legs 4 inch wide 6 inch tall 6 inch long and then the last is about 3.5 inch wide,11inch long and 13 inch tall in front of the pedals. the largest is the area rear of the axle that the 60ah would fit is 13.5x7.5x10

in my mind i have some choices with all this room for activities

first thought is get a large number of 60v 1P packs with individual BMS and just stuff them wherever i can, wired in parallel. This seems reasonably easy to wire, safe and with a custom manufacture like Amorge i could get them in various shaped configurations. this could really help weight distribution as the light weight controller, living for now under the seat, could be relocated to rear of the axle for the heavier batteries to take its place, and other batteries even in that space forward of the pedals this seems like it would be more expensive than the 60ah pack but to be honest I thought this cart would cost me a few hundred bucks and im already a grand into it and have no regrets, why stop now.

other thought was the lug type 38700 lifepo4 batteries, these have insane discharge rates and with this extra space i feel i could packge them either in a large series parallel string going to all areas of the cart with a mother BMS overseeing all. this of course seems like a wiring nightmare and could be very dangerous as more wires is more opportunities for shorts. i have experience with DIY packs but none is the design of a pack built into a EV frame so it could be challenging and require modification but again possibly worth it for very nice weight distribution and versatility if and when i decide to modify the cart again for the other ideas and additions i have (i could write you a book on all the stuff ive done so far and whats to come, its far to much to put here)

third option is to use larger P induvidual packs spread out, same idea as the first just less induvidual packs, less wiring and hopefully less money. per haps 4-6 batteries at 3p. hardest part would be to figuring those packs cell configuration to then pass on to the battery manufacture.

let me know what you guy think i appreciate all the help i can get!

i dont take alot of photos so if your clever youll see in the pic the cart wasnt done yet. its very nice now with full lights w/ blinkers and reverse lights, quick release original powerwheels steering wheel, original dashboard all done up with battery monitoring, speedometer, switchs for lights, key, motor temps, ODO, trip, original powerwheels fm radio w/bluetooth added, original powerwheels shifter for F-N-R action, flip up oldschool schoolhouse chair seat, extra speakers for the radio added, drift rings, front brakes on order awaiting arrival, handbrake for rear coming soon its the foot brake right now, doors still work, trunk still works, seatbelt, custom frame i made to fit inside it, 65 degree from center steering with rack and pinion for big car hand over hand feel, i could go on but ill kill you with the details

yes its for adults, im a 27 year old 5' 10" asshole and hop right in there with room for your sister

 

[MorbidlyObeseKoala]

I don't have direct experience with karting batteries but I am a little surprised I haven't seen more of the larger screwtop cells used considering their claimed massive output and simple assembly/reassembly. I have only seen 1 build on youtube using those but he had monster acceleration up to 60mph or so. A few of the more recent karts I have seen on youtube have 1 or 2 surron batteries that lay on either side of the seat. My general 2 cents is having long parallel connections snaking around the frame is probably a waste of energy since those will have to be real fat to avoid big heat and heavy losses.

If it were me, I'd decide if I want the hoon part right away and purchase the professional battery set up or if I want the building experience and find something reasonably straightforward to connect together/reconfigure and make sure you know how to keep it from catching fire. Literally anything you do will be an upgrade to 60v 5aH, that is so tiny for any real amp draw. You might find your controller and motor can perform way higher with enough punch from a halfway decent battery and you can delay those replacements for a while longer.

room for your sister

She's already dating a loser in Ohio that drives a piece of shit but I'll let her know there's another option when that one breaks down.

 

[Chalo]

Wow, it's like the car version of graybeards riding BMX bikes because that's what they were doing when their life stories peaked.

"Cool".

 

[MorbidlyObeseKoala]

Here is a suspiciously low priced option claiming really high power, link to the website to buy it in the thread.

Honda Clarity Battery

Has anyone played with the Honda Clarity packs? Are there specific reasons why information is scarce in the EV conversion circles?

endless-sphere.com

Additionally, I thought these would be good to put 2 in series for 72v for a pretty compact powerhouse for decent dollar amount since they come in a case with balance wires already connected.

New in Box 110 2170 M50LT 3.6v 5000mah 36v 1.98kWh - $100/kWh

These modules have never been installed and they come with the original box. We also have these lightly used for a little less but if you want them brand new we have a few pallets here still in the original box. These packs have a BMS but we are not 100% sure what the amp rating is. It appears...

batteryhookup.com

You would need to find a bms to suit your needs for either of those options. From what I gather, you typically want something a bit above what your max continuous amperage draw from the battery would be. So for instance if your motor asks for 3000W @ 72V that is around 42 amps. I'd get a bms capable of at least 1.5x that (around 62 amps continuous).

If you were to increase the motor or controller, that BMS kind of needs to be able to handle the max amp draw of the larger component so it can monitor the battery during all operations. You can bypass the power output from the cells directly to your controller but you lose a layer of protection against overcurrent and under voltage and probably logging what the maximum power delivery was and making sure you aren't pushing your battery into a damaging scenario.

Anyways, if all of that was too daunting then you should go with ordering a battery and then post a video of your top speed run in the clown car. I love miniature builds, they are hilarious to watch

 

[chuyskywalker]

Having overhauled a powerwheels for my kid, one piece of hard-earned advice is make sure you have the battery strapped in well. These things have no suspension and love to bounce things right out.

 

[electric_nz]

Neat project! Perhaps you could fit some automotive cells in there - a couple of Hyundai ionic modules or mitsi outlander cells?

Or just get custom 18650 pack - great thing about them is they can be made to any shape.

 

[isthatvinny]

so i have some electric unicycles i also run on 60v and have taken the packs out of one to try in the cart they are good for 60A continous, unfortunately my kelly KVD controller is not what i expected, i have 15-44 12"OD wheel gearing but only get about 17 mph, this is lack luster, ive seen alot of people getting 45-50mph from these motors on even lower gearing, any ideas? might even consider a different controller if its cheap and known.

the motor is not getting warm the controller is not either its not like its working very hard

 

[MorbidlyObeseKoala]

Does it have the torque you expect for higher amps and then stop pulling at that speed? Or is it struggling to get that high off the bat (any stuttering or weird noise)?

After confirming the wiring connections are good and secure (and not wet or corroded) and your kelly settings match what you want to do, you might put a meter on your battery cables to see what the amp draw is. that would help you determine where the bottleneck is (battery/bms or controller/motor). Could also try a different throttle input to see if that went bad.

Forgot to mention: does it behave differently under load sitting in the kart versus off the ground and free spinning? If your rpm on the wheels is topping out the same free spinning off the ground, that would tell you pretty quickly there's probably a setting in teh controller hitting a limit

 

[isthatvinny]

Does it have the torque you expect for higher amps and then stop pulling at that speed? Or is it struggling to get that high off the bat (any stuttering or weird noise)?

After confirming the wiring connections are good and secure (and not wet or corroded) and your kelly settings match what you want to do, you might put a meter on your battery cables to see what the amp draw is. that would help you determine where the bottleneck is (battery/bms or controller/motor). Could also try a different throttle input to see if that went bad.

Forgot to mention: does it behave differently under load sitting in the kart versus off the ground and free spinning? If your rpm on the wheels is topping out the same free spinning off the ground, that would tell you pretty quickly there's probably a setting in teh controller hitting a limit

yes it has the expected torque and is pulling the expected higher amps when accelerating but hitting a limit quickly, yes the speed is the same with and without load. all my speed settings are maxxed out and my wiring is good and not corroded. i have comfirmed my throttle is good and my throttle range set properly. the only thing im leading to is the controller is limiting my speed, why i said it is not what i expected. perhaps there is a setting that will help this but so far i have not found it