[Pirape]

Ok another couple of questions

I was doing plan's on making a 300v system with BLDC motor
with 80-100AH Thundersky batteries

Just with the internal compoments I was busting 20k...


And then I thought of building a very very basic EV

with a buget of 7000$ (Canadian)
Can you guy help me pick a car *excluded from buget* controler, charger, motor & batts (I would like lithium)
the internal compoments of less than 6k so I can have 1000$ of play to purchase wiring and such

30km - 50km range 50-90km/h speed
2 person + room for bags on the back seats
Thanks!

 

[rillip3]

What range and speed do you want? That and budget will determine your choices. Even a relatively small lithium pack can run > 3500 USD, depending on what you want to do.

 

[Pirape]

What range and speed do you want? That and budget will determine your choices. Even a relatively small lithium pack can run > 3500 USD, depending on what you want to do.

for a 144v system, 3.2v x 45 = 144v 45 packs x $50 = 2250$ usd

but maybe I will need more AH lol

 

[rillip3]

Ye olde commuter is ~ 300 wh/mi. 31 mi (50k) means you need 9300 wh + efficiency loss. Increase by 20% for DoD and Peukert, you get 13.4kwh. Divide by 144v = 93 Ah. Lithium batteries, new, are about $1.20 /Ah or so, so you're looking at 45 x 120 = $5,400 for a new pack. If you can find some used at less than half that price, that's great, but you'll want to test the voltage on those batteries carefully. Why would someone be getting rid of them if they were still good? Sometimes you can find batteries like that (I did) but lithium batteries are pretty new and unlikely to be cycled out for no-reason.

Your range is pretty in keeping with PbA, which would cut your initial investment. Some argue that lithium is cheaper over time, but if you can get running now and let your budget grow for a new pack later, that might be an option you want to consider.

A good DC motor will be at least $1-1.5k new. That's 6.9k USD before a controller and the other electric bits. You can save some money there by getting used, but it's hard to predict pricing because it will depend on what's available near you. If you can get a good forklift motor and controller that can save you big bucks; some people have gotten working parts for as little as $250.

 

[Pirape]

Alright! problem solved I will go with lead acid App 2k?

what else?

 

[rillip3]

With PbA you're looking ~ 2k for new. That means you've got 3-3.5k after the motor and batteries. Controller is another $500-1k depending on what you get. If you put out some money for a good one like a Soliton, a lot of the electronics are taken care of for you. If you go for a cheaper one (which doesn't mean low quality per say, just that it doesn't take care of those things for you) you'll look to spend another $200-300 in misc electrical parts like contactors, fuses, the precharge setup, etc. That's really about it that I can think of. You might want to look at some of the build threads and see the things people have run into.