Golf Cart 48v batteries 30AH each

[Surplusdoctor]

It was suggested that a golf cart BMS should be at least 200Amps at 48v. I have 4 small batteries I made from 16 cell of 30AH cells each. I used a Daly smart 60amp BMS on each. If I hook them up in parallel, will that be 240Amps total ????? or just 30Amps?

 

[OzSolar]

Bumping your post to get you an answer from someone other than me since I'm not the best with DIY batteries.

As in 16S for 48v I assume? "On paper" you would be able to get 240 amps from those batteries in parallel them but in practice the smallest of differences in resistances will result on one of them seeing more than 60 amps resulting in it's BMS shutting down.

I don't think it's best practice to parallel BMS's but then again since you've already got them I don't see any harm in trying to make it work. (others will be along shortly to say I'm wrong....)

 

[McKravitts]

As in 16S for 48v I assume? "On paper" you would be able to get 240 amps from those batteries in parallel them but in practice the smallest of differences in resistances will result on one of them seeing more than 60 amps resulting in it's BMS shutting down.

I don't think it's best practice to parallel BMS's but then again since you've already got them I don't see any harm in trying to make it work. (others will be along shortly to say I'm wrong....)

You're not wrong. The problem is that even if you use the exact same model of BMS's the response time could vary and one might deliver current that exceeds it's capacity for a short (very short) time.
This problem can be corrected by adding a capacitor in parallel with the batteries and before any switches/loads etc. The longer the length of wire from the batteries to the capacitor the better. The capacitor will provide current to the load faster than any BMS can and give them all plenty of time to "stabilize"
You'll have to slow charge the capacitor before connecting it into the circuit and anytime after it is drained.

 

[Surplusdoctor]

Bumping your post to get you an answer from someone other than me since I'm not the best with DIY batteries.

As in 16S for 48v I assume? "On paper" you would be able to get 240 amps from those batteries in parallel them but in practice the smallest of differences in resistances will result on one of them seeing more than 60 amps resulting in it's BMS shutting down.

I don't think it's best practice to parallel BMS's but then again since you've already got them I don't see any harm in trying to make it work. (others will be along shortly to say I'm wrong....)

It has been pointed out by a golf cart mechanic I ran into. I ordered 2 BMS that does 80 amps, and for 10 seconds 200 amps each. I will be able to do it with 2 batteries of 30ah each 48v

https://www.aliexpress.us/item/3256806842341070.html?spm=a2g0o.order_list.order_list_main.53.18751802oHS1tM&gatewayAdapt=glo2usa

 

[OzSolar]

It has been pointed out by a golf cart mechanic I ran into. I ordered 2 BMS that does 80 amps, and for 10 seconds 200 amps each. I will be able to do it with 2 batteries of 30ah each 48v

https://www.aliexpress.us/item/3256806842341070.html?spm=a2g0o.order_list.order_list_main.53.18751802oHS1tM&gatewayAdapt=glo2usa

You'll also want to find the specs of your batteries. A general rule of thumb that I've picked up on is that unless otherwise specified by the cell manufacturer the maximum continuous discharge rate is 1C. That puts you at 60 amps.