Constant discharge rate needed

[C_P]

Very newb question. I have built a scooter based on a Razor Ecosmart. I am running a “1800w” 48v brushless motor and controller - Amazon Mophorn. Plenty of power and speed now. The controller is rated (by the label) at 33Amps. I am currently just running off the 7Ah SLA batteries (12V x 4). For lower speed, short cruises around the neighborhood it seems fine, but I did run it all the way down once trying to make back to back top speed runs. I would like to switch to a Li-Ion pack to save weight and increase range in case I want to ride for a bit longer. Most of the 48v eBay packs I have been shopping are 20-25Ah. Triple the Ah seems like it would suffice.

Two questions:
Is there a way to calculate the run time per Ah for the motor/controller?
The batteries I have seen that fit the physical space requirement and budget are usually rated at 25A constant discharge rate. Some are 30A but are 52v. My simple brain tells me the controller will be needing 33A, so those will not suffice. Any recommendations on whether 25-30A constant discharge rated batteries will do the job?

 

[Voltron]

Usually on generic controllers, if it says 33A, that's prob the sustained rating, but is probably pulling more during peaks, like maybe 40, 45A. I'd go higher on the battery rating, depending on how long you want the pack to survive.

Also, if it's just for goofing around, and you're not going to park it anywhere things could catch on fire, maybe look into RC lipo batteries. They have really high amp output for the size of the pack.

 

[flippy]

that is not how this works.

consumption depends on acutal usage. the faster you go the more you consume.

that your controller CAN do 33A does not mean it actually IS doing that constantly. a 500bhp ferrari stuck in traffic is also not producing 500bhp.

buy the biggest battery you can afford and you actually know has proper cells in them. so no china-specials. if the price is too good to be true: it is.

 

[C_P]

Thanks for the replies. Unfortunately chinesium batteries are all that’s in the budget. I probably have $300 in the whole setup, so I can’t drop $750 on the batteries alone to get a brand name option. eBay is hovering around $160.

Any feedback on what the downside would be to running 25-30A continuous rated li-Ion battery pack? If it’s just longevity of the battery pack it doesn’t worry me too much. I do not want to sacrifice torque and power, but given that the old SLAs manage that pretty well I would not expect a loss of either even at a lower “constant rating” of amperage from the Li-Ion.