Firstly, I have read through a ton of these forms. There is a plethora of awesome information. Thanks so much for all of the advice. I'm hoping you can help me with a few questions have while I try to design a cart I have been wanting for some time now. Some background:
I am working on designing a custom cart; something like a hybrid of an electric wagon, and a table. I know this sounds vague but i will give details on the important specifics:
Dimensions:: ~25" width, ~46" long, ~35" high
Weight: somewhere between 750 and 900 lbs.(this includes 244lbs of SLA batteries, if I go that route, more on that below)
Axle type: live axle - 1" width a 1/4" keyway
Tire size (on rear/live axle) - i'm thinking ~12"
Terrain: pavement and grass, mostly flat with some long, gradual hills
Top Speed desired: 10-12 mph
Desired run time of cart between charges: 3 - 4 hours
I want to use one of your motors, speed controllers, throttles, switches, etc. The problems I am running into:
Motor: I am not sure which motor to install on the cart. What are the differences between your 36v motors and your 48v motors? How do i determine the torque required to push the cart? Do you know the torque output of each of your motors? Will either be able to push a cart weighing 900lbs?
Batteries: I am quickly learning that they will be the most expensive and heaviest part of the "motorization" of the cart. What are my options? At first thought, going with a 36v motor means I can purchase/carry one less battery; what are the drawbacks of that vs going with the 48v motor (and consequently 4 batteries)? I can't determine if I want to use SLA batteries or if I want to splurge on some 12v Lithium-Ion batteries. It looks like they sell some for ebikes that come with a harness already attached to the battery (these batteries are in all sorts of weird/custom shapes) and then some Lithium-Ion batteries that closely resemble the SLA batteries that you sell on your site. Will either work or do I have to stick with the ones that resemble SLA batteries? Both seam ridiculously expensive. How do I calculate how much motor run time I will get out of a given ah battery? Can you explain how different motor voltages will impact this?
Sprocket: I noticed that most of your 1000w and 750w motors come with a sprocket that fits 8mm chain. I am having a hard time finding sprockets that will fit that that go on a 1' live axle. Are there other options that you sell that can be installed on the motor to run more "generic" chain, such as bicycle chain?
Thanks so much for all of your help with this. If I have left out an pertinent information, please don't hesitate to let me know. I can't wait to get welding!
I used Azusaparts.com for my axle, bearings/hangers, sprocket/hub, key shaft, and wheels. I also opted for a 1" live axle and they cut me a custom 27 tooth aluminum sprocket for #415 chain. They have a bunch of sprocket options. Then took the hub from azusa to a local machine shop to cut it down to fit my small axle sprocket. Matching all the power transfer stuff is a pain. Good luck with the build.
We have created many online calculators for determining what size battery pack, motor, charger, and other parts are needed for various riding conditions. Here are links to some of these calculators: