Electric vehicle battery question

Click For Summary
SUMMARY

The discussion centers on selecting an appropriate battery for an electric vehicle, specifically a slow-moving electric wheelbarrow powered by a motor with a maximum mechanical power output of 400 Watts. The user requires a compact solution, opting for a single 12V 100Ah battery. Two primary solutions are proposed: using high peak current cells like Li-Ion or Molibnium, which are costly, or implementing motor control circuits that utilize reservoir capacitors to manage high starting currents while maintaining optimal average current from a lead-acid battery. The latter approach also enhances motor protection during demanding conditions.

PREREQUISITES
  • Understanding of electric motor specifications, including torque and efficiency
  • Knowledge of battery types, specifically lead-acid and lithium-ion technologies
  • Familiarity with motor control circuits and their applications
  • Basic principles of electrical current management and peak current delivery
NEXT STEPS
  • Research "Li-Ion battery specifications for electric vehicles"
  • Explore "designing motor control circuits with IGBTs"
  • Learn about "reservoir capacitors and their role in electric motor applications"
  • Investigate "efficient battery management systems for electric vehicles"
USEFUL FOR

Engineers, hobbyists, and developers involved in electric vehicle design, particularly those focusing on battery selection and motor control strategies for compact applications.

akueddy
Messages
14
Reaction score
0
Hi,
i really hope someone can help me with this...
what type of battery that is suitable for an electric vehicle(slow walking speed,electric wheel barow)? is it a deep cycle marine?
I have a problem on how to choose the correct battery.
i have choose a motor which can produce a max mechanical power output of 400Watts.
http://www.boschmotorsandcontrols.c...2/kennlinie.htm

if you look at the characteristic curve, my working torque would be around 2-3Nm, the corresponding current required is about 100A. The problem is due to the fact that the vehicle need to be as compact as possible, i can only choose one 12V battery 100Ah battery. i initially try to pick the right motor by using the assumption that, stall torque>torque require.This i know is not efficient+the rpm is slower near stall torque.
Right now the motor that I've choosen got the right working torque(2-3Nm) and rpm, and is >50% efficient but the power source could not supply more than (2-3Nm), what happens if the required torque is more than 2-3Nm??
 
Last edited by a moderator:
Engineering news on Phys.org
There are two solutions. One is to use cells with high peak currents such as Li-Ion or Molibnium, but these are expensive and generally only used in Electric Cars as opposed to Electric Wheelbarrows unless weight is a driver above cost.
The other option is to use motor control circuits to deliver the very high starting currents from resevoir capacitors whilst keeping the average current drawn from a Pb-Acid cell near the optimum for capacity. This slows your acceleration but gives you good running times.
The motor control solution also protects the motors when the going gets tough as they can be used to limit the average current seen by the motor and switch out if a dead stall occurs.
Unless you are looking for a lightweight wheel barrow with good 0-60 times I would look at building a motor controller using IGBTs such that peak current is delivered to the limit of the motor and average current is delievered at no greater than 2-3C of the Battery.
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
Replies
5
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 13 ·
Replies
13
Views
2K
Replies
3
Views
3K
  • · Replies 5 ·
Replies
5
Views
4K
  • · Replies 117 ·
4
Replies
117
Views
11K
  • · Replies 11 ·
Replies
11
Views
5K
  • · Replies 7 ·
Replies
7
Views
3K