How to build 72v 50ah battery packs for my navitas golf cart

[Rhetts97]

I am currently running 3 48v 30ah batteries on my 600amp navitas controller and 5kw motor, I would like to upgrade to 2 72v 50ish ah battery packs I was hoping for some diy information if anyone has any?

 

[42OhmsPA]

I'd check out the 7s-21s 300A BMS on Battery Hookup, they have various cells too.

Welcome to the forum.

 

[Rhetts97]

Thank you, I'll look at them.

 

[BigGun]

These batteries at Battery Hookup might work for you. Buy 4 and run them in a 2S2P configuration. They have a serious amp output. You would need to wire in your own BMS. Two would run the Shit out of that cart, but only 67AH

https://batteryhookup.com/products/new-8s-black-samsung-30-4v-67ah-2-04kwh-lithium-ion

 

[Rhetts97]

Those will not work the voltage is too low, those say 30v each so series would only get me like 60v?

 

[BigGun]

I'm curious what 30AH battery x 3 is giving you 600 amps

 

[Rhetts97]

They are not giving me but 60 amps per battery so 180amps total when wired in parallel.
I am looking to go to 72v for 2 reasons more amps and more rpms,
The navitas kit I have is capable of running 48v or 72v the motor is an ac motor so the controller converts the dc power to ac for the motor,
So instead of going 33mph I should hopefully be able to go around 40 to 45ish with stock gears.

Hope this makes sense.

 

[BigGun]

You need to know the Low/High limits of your controller.
I've converted a couple carts and put the Navitas 400 amp on stock motors. They pull around 385 amps on take off , but taper down pretty quickly to around 90amps. Top speed around 30

 

[yabert]

You post on the diy Lifepo4 forum, so I'm not sure if you are interested by EV NMC chemistry.
If yes, look at kia EV6/Ioniq 5 battery module.
There are 6S (22V nominal), 107 ah, weight around 24 lbs, compact and if you put 3 in series (18S) that can give you an awesome battery.

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[Rhetts97]

I can adjust it anywhere from 100amps to 600 amps but my current batteries do not allow anything over 180amps tho so that is why I want to build 2 72v at 50ah that way I would have ample power plus if one pack or bms goes out I can still make it home.

 

[BigGun]

Voltage limits for your set voltage 48 or 72. Most controllers have a Low and High limit. You need to know this in order to build any kind of pack.