Custom Battery Management System by using LTC3300 and LTC6803

Hello Engineers,

Short context intro: I am mentoring a project at a youth makerspace, and we are building an electric vehicle from the ground up. We are tight on budget, be we have done an EV conversion project previously. Battery management was a failure point for our previous project though, and we want to do things right this time.

Spending $1000 on a BMS is not what we would like to do if we can build a custom BMS with LTC3300s and LTC680s, that would be a preferred method. (We have two parallel battery packs, and each pack contains 24 LiFePo batteries of 3.2V)

Our we out of our league on this though? We do have electrical engineers that can assist us and we have a fair amount of equipment at our makerspace also.

See page 46 - www.analog.com/.../33001fb.pdf

Thank you in advance

  • 0
    •  Analog Employees 
    on Dec 3, 2018 3:30 PM

    Nathan,

    My experience suggests you would not have a problem with the LTC680x (cell-voltage monitoring), but the LTC3300 (cell balancing) would be a difficult goal.  The balancer design requires careful layout and attention to a number of dc-dc converters with a large number of potential problems along the way.  If you have the money, I think you would be better off buying the existing DC2100B boards.  If you are looking for a challenge, develop the LTC3300-based balancers by starting with the layout and design of the existing DC2100B.

  • WA Taylor - Thank you for your advice on this. I think your answer informs me on the things I felt lacking in my understanding. However, since writing my original question we have realized our battery configuration idea of two packs in parallel was a silly mistake in planning. We now know we will need to do one pack with the batteries pair off in parallel. This configuration I believe is termed 24S 2P - 24 in series and 2 paralleled in each 'cell' of the string.