Some consideration about the DIYBMS


I just finished my setup 16S1P with Prisma cells.

  • Large controller board
  • 16 board V4.4.
  • Victron Multiplus IIGX 3000/48/35
  • 16 280 Ah Prisma cells.

No when I´m finished I see the limitation of the BMS.

The BMS does not really balance the cells.
It burns off energy when one cell has to much current.
But under balancing I would understand to transfer energy to an other cell.

Is there any idea of modified boards ahead which are able to tranfer instead of burn?

Other hands…
Any chance to fit a fan to the heated resistors to cool them?
So when burning energie starts the energy is also used to produce airflow?

Best Regards

Hi Joshi,

the balancing function of the diyBMS is only burning energy of the cells which have reached the programmed value. Its a passiv balancer.
If you want to have transfer power from high level to low level cells, you must integrate a active balancer too.
I installed an active balancer in addition to the 4.4 boards and it works well.

Best greetings from bavaria,

Hi Jochen,

I know now. But it was not clear for me when I started the project.
However. Which active solution do yo have in addition?
What are the costs of it.