DIY 36volt build can you identify this cell

Contemplating a DIY build for 36volt golf cart as I don't see any premade that are serviceable and or afforable.

My first question is does anyone recognize or know anything about this cell I found on amazon.

And trying to avoid the troubles with alli sites.

I came across those last night on Amazon myself and wondered who what when where why how

the only thing close I could find was on Noah Ark list of mfg's he had a picture of calb cam series but aluminum case only show up in 72ah & 80ah. Can't tell if the vent is the exact same or not. And the calb terminals are slightly different.

kytoon said:

Contemplating a DIY build for 36volt golf cart as I don't see any premade that are serviceable and or afforable.

Click to expand...

I installed this kit, Golf cart application is a tough as the peak currents involved are quite high. Add in BMS, case and I doubt your going to see any savings over the lifetime going DYI route.

Ive read reviews from that seller before... people got bloated cells and they told them it was perfectly normal.

Also no specs given as far as c rates but judging by the dimensions those cells are limited to 150 to possible 200 amps dicharge..
For my 48v golf cart pack, I used these cells specifically for thier higher 3c discharge rate (and the low cost) https://www.aliexpress.us/item/2251...2Ekl9Rq&gatewayAdapt=glo2usa&_randl_shipto=US (shipping did take 2 months)
Im using a JBD 300a relay type bms (300cont 500peak) my pack with the steel enclosure which provides compression, the 500a terminals, 5a active balancer, 300a bms with the touch screen interface along with a 22amp charger (used on ebay for $90) and flexible tin plated busbars cost me about $900... but the cells I linked above are technically only 86ah according to the bar codes not 90ah

The big battery setup above is a good value for a stock cart but if you have a higher current/amp controller or bigger tires you will likely be exceeding the low 115amp rating and tripping the bms as many on buggies unlimited have reported with the weaker packs. (if you got 4 or the 32ah packs you wouldnt have this issue as long as 4 bms play nice together)

there are lots of serviceable packs out there premade but they are pricey. Like the Roypow or the eco battery packs and many chinese direct packs. Even docan power offers a made to order pack in a steel serviceable enclosure. most places have at least a 100% markup over cost though mainly for warranty and "support" for those that need it.

here is a link to my ongoing build. my busbars should arrive today.

augiedoggy said:

The big battery setup above is a good value for a stock cart but if you have a higher current/amp controller or bigger tires you will likely be exceeding the low 115amp rating and tripping the bms as many on buggies unlimited have reported with the weaker packs. (if you got 4 or the 32ah packs you wouldnt have this issue as long as 4 bms play nice together)

Click to expand...

You are required to have minimum 2 and on the Alltrax controller I have it programmed limit to 200a peak on the battery amps to keep the load reasonable. The motor still goes to 400 amp peak as with series wound motor its like a coil in a buck converter.

I have 23" wheels and cart does ~34mph with a pair of the 36V Raptor batteries. Even limiting to 200a on the battery has no measure effect on acceleration as its motor amps limited and as the speed increases, it becomes the voltage that limits with series wound motors rpm.

Its maybe a fun science project to make your own battery,bms,box but with time and effort included it's not a cost savings

Solar Guppy said:

You are required to have minimum 2 and on the Alltrax controller I have it programmed limit to 200a peak on the battery amps to keep the load reasonable. The motor still goes to 400 amp peak as with series wound motor its like a coil in a buck converter.

I have 23" wheels and cart does ~34mph with a pair of the 36V Raptor batteries. Even limiting to 200a on the battery has no measure effect on acceleration as its motor amps limited and as the speed increases, it becomes the voltage that limits with series wound motors rpm.

Its maybe a fun science project to make your own battery,bms,box but with time and effort included it's not a cost savings

Click to expand...

I see they are only sold in 2 packs which is why I assumed incorrectly the specs were for the 2 pack and not individual packs. that is a decent deal. Theres a rather lengthy thread on the golf cart forum where someone who managed to 3 three of the 48v version for a 96ah pack is having a lot of trouble keeping all 3 of them working at once but in fairness it could be something his shop did wrong and cant figure out. and the recommended charging voltage big battery had speced for them is 58.8 and 44.3v which is normally for nmc not lifepo4. Unless im missing something that doesnt instill much confidence they should have 43.8 and 58.4v chargers if charging to the max recommended 3.65v per cell like just about everyone else including the cell manufacturers recommend. my guess is they are not even Lifepo4 as advertised but NMC instead and the marketing team (guy) doesnt even know the difference.. which would be scary. On thier website they even falsely claim Lifepo4 has more energy density than NMC? I mean if they cant even get the chemistry right what else might be incorrect?

But again... The 260amp continuous /500amp 48V* (if it were 36v it would have cost me about 700) solution Im throwing together for $900 is saving me a considerable amount over anything I could buy so your statement is pretty relative to what you consider a "cost savings" Plus I will be in a better position to service it if the time comes...

As far as "Time and Effort" being a negative costly thing vs something I get enjoyment out of and joined this forum for, I guess in my case it makes the advantages of DIY even greater. I have to ask though based on your take on it, Why are you wasting your costly time and effort on in a DIY battery forum trying to negate the positive aspects of it to others? You've already made your choice right?

Limiting the battery current to 200amps can get you like 380amps at the motor but depending on terrain, the amount of people in the cart and the size of the tires as well as the motor in your cart you would find situations where the motor wants more. Like you said speed is about voltage and torque is about current. Such a current limitation on my controller also puts more stress on its components and increases the chance of failure.. being that a replacement for the controller I have costs over $800 I feel I could benefit a bit from having more juice on tap.

augiedoggy said:

the recommended charging voltage big battery had speced for them is 58.8 and 44.3v which is normally for nmc not lifepo4.

Why are you wasting your costly time and effort on in a DIY battery forum trying to negate the positive aspects of it to others? You've already made your choice right?

Limiting the battery current to 200amps can get you like 380amps at the motor but depending on terrain, the amount of people in the cart and the size of the tires as well as the motor in your cart you would find situations where the motor wants more.

Click to expand...

That is the working voltage range 44 - 58 , charging is 58 and they are Lifep04. I use a stock charger, that I opened up and adjusted to lower the voltage a bit. The internal BMS with also disconnect if over voltage so it really isn't an issue, I just saved the $300 not buying their "Lifep04" one

I've done lots of projects. spent many hours on what-ifs and sharing for others what I have done. This isn't a cult, its a place to share information. Every solar system I have built was my labor, good shopping for discounts, but sometimes like for golf carts, it was not worth the time for potential savings.

Controllers are just a PWM switching the low-side of the motor, so I can go from 0 to 17mph with full 400 amps available ( 0 to 50% duty cycle ), so there is no limit there. With series wound motors the current it can draw is linear to the rpm, so at 17 mph ( ~ 3200 rpm ) the motor max draw is ~200 amps so from there the rpm limit, its all about voltage.

FYI, I don't have a stock motor, its the AMD raptor ( 6hp ) series wound, drop in replacement for the EZ-GO to the transaxle.

Now there are AC motors and controller kits , that would be the next cart if I ever do it again

Yeah golf cart controllers are more than just a pwm device.. and i never said anything about any cults.
Its really the OPs decision to decide if paying double for a premade option is worth his time. my guess though is the reason hes here is he already decided he wants to research building his or her own pack.

As far as the standard 12s and 16s lifepo4 charging voltage being the same as NMC? and relying on the bms as the only line of defense to prevent overcharging thats your call... If you google 58.8v or 44.3v charger you will see they are meant for 3.7 NMC batteries and 58.4 and 43.8v chargers are specifically designed for 3.65v lifepo4. If it really didnt matter you wouldnt see the separate built and sold options for each.

Big batteries own page selling the 44.3v charger to go with a battery they spec for max charging voltage of 44.1v right next the the "charging range of 41.7-43.5V all counterdict each other and paint a picture of a company that doesnt have their ducks in a row or is flat out making stuff up.

A lot to digest. My concern with premade is I don't want a $1500 anchor. All of the brands I've seen are laser welded cells. So yes we can open the box and change the bms that's good but if just 1 cell goes out it is essentially a big nothing. While I am hope full that the 5 year warranties are viable, I also consider what if they are not still in business what are my options after they have my money. I'm stock motor and stock PDS controller. Tires are farm lugs but not lifted ballon tires.

thanks for input

kytoon said:

While I am hope full that the 5 year warranties are viable

Click to expand...

10 years on the ones I purchased, it is Lifep04 and so far plug and play.

Honestly, with ANY new technology, it is very probable companies will come and go, at least with US based there is hope, when you by stock from outside the USA, once the payment is cleared, there is no warranty of any type.

An when you build your own, unless you purchase a few extra spare cells, rebuilding later if needed maybe impossible as the cells size/shape/chemistry is changing so rapidly.

Best wishes on any path your should take, anything is better than Lead Acid for golf carts and will be an improvement!

kytoon said:

Contemplating a DIY build for 36volt golf cart as I don't see any premade that are serviceable and or afforable.

My first question is does anyone recognize or know anything about this cell I found on amazon.

https://www.amazon.com/dp/B09X8GGQ68/?coliid=I2UD3HZ8J0Z409&colid=3CD05GJR1MQO6&ref_=lv_ov_lig_dp_it&th=1

And trying to avoid the troubles with alli sites.

Click to expand...

Supposed to be the specsheet for these cells from expert power in response to an email...

so only 100amps discharge which is too weak for most golf carts.

Yes. fine for those of us that are just going to use it for solar power. But not for running motorized vehicles or somebody that might be trying to generate a fair amount of heat from batteries which is well really not such a recommended thing unless you build some really serious battery bank and have lots of solar panels

QUOTE="augiedoggy, post: 693054, member: 68196"]
so only 100amps discharge which is too weak for most golf carts.
[/QUOTE]

You might find this interesting.

kytoon said:

Contemplating a DIY build for 36volt golf cart as I don't see any premade that are serviceable and or afforable.

My first question is does anyone recognize or know anything about this cell I found on amazon.

https://www.amazon.com/dp/B09X8GGQ68/?coliid=I2UD3HZ8J0Z409&colid=3CD05GJR1MQO6&ref_=lv_ov_lig_dp_it&th=1

And trying to avoid the troubles with alli sites.

Click to expand...

let me know what BMS you decide to go with.