Battery Vehicle Society

Hello to those interested in helping me,

I am an undergraduate Electrical Engineering student at Lakehead University. We are designing a Hybrid Electric Vehicle (crappy website link: http://hybrid.lakeheadu.ca/webcam.html) and I stumbled upon the battery vehicle society website and think it would potentially be extremely useful, but it is also extremely overwhelming as well. My group is in responsible for charging 40Ah lithium-polymer batteries from scratch as part of a whole HEV system. We do have access to a microcontroller which will be integral part of our design, but we are all brand new on lithium batteries. Our problem so far seems to be designing a constant current regulator to be able to charge the batteries at constant current (very high current). Right now we were thinking about having the whole bank in series and charging them with a balancing circuit in between the terminals of each battery integrated with the microcontroller.

ANYWAYS, we really don't know much (beyond a few basics) even after researching for a couple months and was just acting kindly if you could aid us or send us in the right direction to design a system that would be able to do what we are trying to do and that is charge and balance our 40Ah batteries. We also have a smaller 10.8V 5200mAh battery pack with 8 cells from a laptop and was going to charge that first to be able to start small scale and work our way up possibly but its even difficult really to find circuits that will help us do that. So please just let us know if you can be of assistance.

The main thing is though, we also cannot just purchase a charger/balancer, but we are supposed to design the system.

Thank you so much for you time and consideration,
Paul
(and the rest of the Lakehead Hybrid Vehicle SAE team)

See my reply via PM. All the info you need is in these BMS threads.
Give yourself a week to read a major chunk of it. Then ask relevant questions in the specific threads.

Peter

Hi guys,

Im newbie here..anyway I amm a final year undergraduate student in one of the university in malaysia. Im currently doing BMS as my final year project. I am focusing more on passive type of cell balancing. However, i have problems to start on designing the circuit. need some advice on this matter. Really appreciate for your help. Thank you.

As Peter says;