LiPo Batteries on a Go-Kart?

[SquidBonez]

I've been doing some research and debating between using the 80V Greenworks/Kobalt power tool packs in parallel or going with RC LiPos. I've seen quite a few go-kart/minibike builds using LiPos, and only one guy out there seems to use the Greenworks packs. My only fear regarding LiPos is the fire risk, and the fact that they don't have any BMS system to keep them from over-discharging when riding. Does anyone here have experience or advice about using LiPos?

I could get a lot more power out of a LiPo setup but they seem way more unstable. All in all, I'm trying to avoid having to build my own Li-ion pack and looking for "off the shelf" components.

 

[panchothedog]

I use lipo's a lot running fast electric R-C boats. High AMP draw ( 120 to 180 )
but lower voltage. 4-s 14.8 volts, and 6-s 22.? volts. Probably own 45 to 50 batteries. Stability has not been an issue. But over discharging either by running the boat too long, or by to big of a load ( pulling amps out quicker than the C rating is capable of ) usually ends up with a overheated and puffed battery. Basically trash. Never had one catch on fire or explode. Being pricey
as they are, it's something you learn to avoid.

 

[SquidBonez]

I use lipo's a lot running fast electric R-C boats. High AMP draw ( 120 to 180 )
but lower voltage. 4-s 14.8 volts, and 6-s 22.? volts. Probably own 45 to 50 batteries. Stability has not been an issue. But over discharging either by running the boat too long, or by to big of a load ( pulling amps out quicker than the C rating is capable of ) usually ends up with a overheated and puffed battery. Basically trash. Never had one catch on fire or explode. Being pricey
as they are, it's something you learn to avoid.

I'm looking at Turnigy 6s 20000mAh 12c batteries. Thinking about wiring 3 in series for 75.6V fully charged and a max discharge of 240A. This would be good for a bit over 18KW, but I'd be running closer to 15KW (so 200A or so). This will be going on an offroad go-kart that currently has a Duromax 440cc pushing about 21 horsepower, so I want something that will at least match the power output of it.

 

[Mr.Mediocre]

I don’t know anything about battery chemistry but LiPo’s alway remind me of when I worked for Apple and we had to have all of these wild safety precautions for those soft-cell batteries. I love the idea of using the ”off the shelf” like you said, now you have some version of BMS built in and the added hard shell for safety.

 

[EpsilonZero]

You can use the LiPos. Just be sure they are easily removable and that you remove them from the kart for charging in a safe place. Also ensure you balance charge them and avoid over-discharging and drawing too much current. A BMS and/or controller settings will help with this.

 

[SquidBonez]

You can use the LiPos. Just be sure they are easily removable and that you remove them from the kart for charging in a safe place. Also ensure you balance charge them and avoid over-discharging and drawing too much current. A BMS and/or controller settings will help with this.

Do they sell BMS systems that work for LiPos? Most people I've seen just use a balance charger. How do I protect from over discharging? I know they make low voltage alarms but is there any sort of cut-off system? If I can figure out how to safely use these batteries then they would be a cheap(ish), powerful, light, and compact off-the-shelf option with tons of information avaliable about them.

EDIT: I also found these supposedly solid-state drone batteries that would work too:

High Power Density Light Weight Drone Solid State Lithium Battery 10C

The solid-state Lithium batteries use a solid electrolyte comparing with the Lithium polymer (Li-po) battery and Lithium-ion (18650) batteries pack that use liquid electrolytic solution. Solid-state batteries have higher energy density than the Lipo or Li-ion batteries have, they store twice as...

unmannedrc.com

I thought solid-state batteries were still in development. Are these actually solid state batteries? If so they should be less prone to fires, right?

 

[panchothedog]

SquidBonez
I don't know enough about this outside of my usage experience to give advice.
Turnigy batteries are very well known in the RC world. Good product. Have never heard of a 20000 Ah battery, and a 12c rating seems extremely low. But
your math is correct, it should withstand 240 amp draw. MAX. On 4000 to 6000
Ah batteries we usually look for a 50 to 70 C rating. Don't know what a BMS
controller is , I assume some sort of low voltage cut off? Anyway let me suggest a website many in the RC boating hobby use. Not so much for batteries, but there brushless motors capable of 10 to 12 hp. 7500 to 9000 watts and ESC' s ( speed controls ) capable of 300 amps.@ 15-s. About 60 volts. One on each wheel would give you what you are looking for. Might not be
practical. Forgot, the ESC's all have adjustable low voltage cutoff. The website
is Off Shore Electric.

 

[EpsilonZero]

Do they sell BMS systems that work for LiPos? Most people I've seen just use a balance charger. How do I protect from over discharging? I know they make low voltage alarms but is there any sort of cut-off system? If I can figure out how to safely use these batteries then they would be a cheap(ish), powerful, light, and compact off-the-shelf option with tons of information avaliable about them.

EDIT: I also found these supposedly solid-state drone batteries that would work too:

High Power Density Light Weight Drone Solid State Lithium Battery 10C

The solid-state Lithium batteries use a solid electrolyte comparing with the Lithium polymer (Li-po) battery and Lithium-ion (18650) batteries pack that use liquid electrolytic solution. Solid-state batteries have higher energy density than the Lipo or Li-ion batteries have, they store twice as...

unmannedrc.com

I thought solid-state batteries were still in development. Are these actually solid state batteries? If so they should be less prone to fires, right?

Yes, there are BMSes that work with lithium. You can set a low voltage cut-off in programmable controllers normally and BMSes can have a cut-off as well. You can just top-balance your packs when you charge them and use the controller to prevent over-current and over-discharge. That's what I do, though I built my own LiFePO4 battery instead of using LiPos.

Those solid state batteries have a terrible cycle life and will quickly need replacement.

 

[SquidBonez]

SquidBonez
I don't know enough about this outside of my usage experience to give advice.
Turnigy batteries are very well known in the RC world. Good product. Have never heard of a 20000 Ah battery, and a 12c rating seems extremely low. But
your math is correct, it should withstand 240 amp draw. MAX. On 4000 to 6000
Ah batteries we usually look for a 50 to 70 C rating. Don't know what a BMS
controller is , I assume some sort of low voltage cut off? Anyway let me suggest a website many in the RC boating hobby use. Not so much for batteries, but there brushless motors capable of 10 to 12 hp. 7500 to 9000 watts and ESC' s ( speed controls ) capable of 300 amps.@ 15-s. About 60 volts. One on each wheel would give you what you are looking for. Might not be
practical. Forgot, the ESC's all have adjustable low voltage cutoff. The website
is Off Shore Electric.

Yep they're actually capable of 24C bursts 12C continuous. And I initially planned on doing a dual RC motor swap which I have seen done before, but I'm planning on just doing one larger motor - probably a QS138 90H.

Yes, there are BMSes that work with lithium. You can set a low voltage cut-off in programmable controllers normally and BMSes can have a cut-off as well. You can just top-balance your packs when you charge them and use the controller to prevent over-current and over-discharge. That's what I do, though I built my own LiFePO4 battery instead of using LiPos.

Those solid state batteries have a terrible cycle life and will quickly need replacement.

Yeah I've seen BMS systems that work with Li-ion but I'm not sure if they would be compatible with LiPo as well. What controller do you use? I've seen many use a BAC4000-BAC8000, but which do you reccomend for easy tuning/programming? Also what do you mean terrible cycle life? I assumed all RC batteries had shorter lifespans than most batteries. These batteries are still LiPos, they just have a solid electrolyte instead of a standard liquid electrolyte. Are they that much worse than standard LiPos?

 

[EpsilonZero]

Yep they're actually capable of 24C bursts 12C continuous. And I initially planned on doing a dual RC motor swap which I have seen done before, but I'm planning on just doing one larger motor - probably a QS138 90H.

Yeah I've seen BMS systems that work with Li-ion but I'm not sure if they would be compatible with LiPo as well. What controller do you use? I've seen many use a BAC4000-BAC8000, but which do you reccomend for easy tuning/programming? Also what do you mean terrible cycle life? I assumed all RC batteries had shorter lifespans than most batteries. These batteries are still LiPos, they just have a solid electrolyte instead of a standard liquid electrolyte. Are they that much worse than standard LiPos?

I suppose you're right; LiPos have a terrible life cycle in general. I consider an estimated 300 charges before significant degradation to be pretty terrible. It isn't so bad when dealing with just a single pack, but it is a bit more expensive for karts and the propensity for lots of fire is there as well. They are convenient and relatively light, though.

I have used several no-name controllers for smaller projects, but I use Kelly controllers for my big kart. I am on my second controller (KLS6030H, KLS7250N-R) with the third (KLS72701-8080NPS) waiting in my garage on the latest motor to be delivered for installation together. All of my larger motors have been Motenergy motors (ME1305, ME1717, ME1719, ME1114). None the controllers or motors have failed; I just like repeatedly upgrading.

 

[SquidBonez]

I suppose you're right; LiPos have a terrible life cycle in general. I consider an estimated 300 charges before significant degradation to be pretty terrible. It isn't so bad when dealing with just a single pack, but it is a bit more expensive for karts and the propensity for lots of fire is there as well. They are convenient and relatively light, though.

I have used several no-name controllers for smaller projects, but I use Kelly controllers for my big kart. I am on my second controller (KLS6030H, KLS7250N-R) with the third (KLS72701-8080NPS) waiting in my garage on the latest motor to be delivered for installation together. All of my larger motors have been Motenergy motors (ME1305, ME1717, ME1719, ME1114). None the controllers or motors have failed; I just like repeatedly upgrading.

If I can't do LiPos then I suppose I could use a couple e-bike batteries in parallel.

 

[Denny]

My ex wife had liposuction does that count?

 

[SquidBonez]

Did some more looking and apparently they do have LiFePO4 batteries for RC. However they're usually much smaller capacity so I would need like 16 of them which would be a pain to charge. They are, however, very safe in comparison to LiPo. So right now its really just a balance between power and safety (the age old question). Otherwise building a custom pack (which I want to avoid) is my last resort.

 

[Bmr4Karts]

My Gokart Lipos just showed up. My controller is 200 continuous 500 max

 

[Bmr4Karts]

I'm looking at Turnigy 6s 20000mAh 12c batteries. Thinking about wiring 3 in series for 75.6V fully charged and a max discharge of 240A. This would be good for a bit over 18KW, but I'd be running closer to 15KW (so 200A or so). This will be going on an offroad go-kart that currently has a Duromax 440cc pushing about 21 horsepower, so I want something that will at least match the power output of it.

I would double up on that. Never trust the C ratings

 

[SquidBonez]

I would double up on that. Never trust the C ratings

Double up on what? Do another set of batteries in parallel?

 

[Bmr4Karts]

Double up on what? Do another set of batteries in parallel?

Yes, for amp capacity.

 

[Functional Artist]

Um...(maybe I missed it) what motor & controller are you wanting to power?
...& on what size kart
...& what size rear wheels?

 

[SquidBonez]

Um...(maybe I missed it) what motor & controller are you wanting to power?
...& on what size kart
...& what size rear wheels?

From what I've been looking at I'm thinking QS138 90H, might go for a BAC8000 controller. Kart would be between 350 - 400 pounds, 18" rear tires.

 

[Bmr4Karts]

From what I've been looking at I'm thinking QS138 90H, might go for a BAC8000 controller. Kart would be between 350 - 400 pounds, 18" rear tires.

Not a very strong motor for a 500-600lb kart with rider. What are your top speed goals? Acceleration? Hill climbing ability?

If that is the motor you go with than those 20ah lipos probably would be enough.