Inwo, Again I love all your feedback and support for our question, but a little more science behind the why or what exactly is going to make everyone so grouchy would be helpful.
To your previous response, our campus speed limit is 10mph and I am not sure how comfortable I would be with an autonomous vehicle built by students going over 5mph. The steepest grade we have might be 3% and it is going to be a long time before this vehicle is carrying passengers. Also, we have a limit of $1800 for batteries and charger. My guess is one of the highest peak current draws we are going to have is just from stop to start. Any numbers on that?
Then just buy what you want, you asked for input. Some of the most knowledgeable people in the country have responded.
It is not an argument - if you think the math works, go for it. We wish you all the best on the project, it sounds really fun.
Personally, It would be better to build in lots of overhead on your power systems. Long days of debugging and repeat runs will only be complicated by an anemic battery bank.
Thinking out loud-
Also- How are you going to power the other systems on this cart? Are the other systems going to have dedicated power systems? Are you going to have rotating caution lights/Lidar/Cams/Sensors/computers/Servo motors?
What sort of tests is this car going to be submitted to? Level ground only? Steering between cones? Maybe some rolling hill climbs?
Is there going to be an operator mode? I’d think the car will be needing a “rabbit mode” just to get it from the shop to the track area where it will be switched to “turtle”. Doing this at 2mph is going to be painful if it is any sort of distance away. Faster is more amp demand and consumed. Are you going to show up out at your test track for a day of testing with 70% battery?
Yes, 350a.
Unless you turn the acceleration and torque way down.
I have nothing against low capacity cheap batteries. Just not these.
Look for “C” rating before you buy, then bms rating.
Previous limit was $2500.
I saw no response to my PM so don’t know what else I can do!
Grouchiness setting in, and will soon withdraw my offer.
If you are anywhere near NorCal or close enough to ship/transport, i have six lightly used 105ah flooded lead acid deep cycle marine batteries sitting that you can have.
@stkchristy, Here is my input. You have received decent advice for batteries, except for one thing.
don’t use lead acid flooded batteries. My choice has always been GEL 104ah batteries. There are several inexpensive choices o choose from. Prices vary by brand.
I experimented with several sizes and found 50ah gave me very little mileage. That means you have to charge them way more often. As far as speed, it would be just like a car. You can travel at 10mph, as I do this, in certain areas I travel in. I suggest following the specs for the vehicle, for longer lasting life span. 50ah may work for you, but replacement time may be more than twice as short.
