REC ABMS - integration with heltec 4s Active Balancer

• S

  Stefano

  8/26/25, 5:17 PM

  Hi all,

  I'm building and testing a 3P4S battery using EVE314Ah cells. The battery's size is pushing the limits of the ABMS's balancing capabilities.

  I'm considering integrating a Heltec 5A active balancer to help keep the cells in balance. In principle, I could connect the Heltec balancer, and it would do its job by adding current where needed. However, I'm concerned it might unpredictably interfere with the ABMS's own balancing function.

  An alternative I'm considering is to connect the Heltec's run/off switch to the REC ABMS's relay. I would create a logic that allows the Heltec to handle the heavy lifting during the initial part of the balancing process—for instance, when the cells are between 3.4V and 3.5V. Once a sufficiently high state of charge (SOC) is reached, the ABMS would turn off the Heltec and finish the balancing itself (e.g., from 3.5V to 3.58V). Note that these are illustrative numbers only.

  Any thoughts on the best approach would be greatly appreciated.

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• R

  Rick OGM Support Staff

  8/26/25, 9:01 PM

  We have many users with 4P4S EVE packs running the REC Active BMS without any need to add balancers.  Unless you are mating cells with different capacities the Active BMS will balance your pack under most conditions, so long as you are topping up your pack on a fairly regular basis.

  I would suggest you first test you system just using your BMS with default parameters

  If not enough, I would then lower you start balancing threshhold down as low as 3.4V to start the process sooner

  If you still have issues only then add your external balancer, making sure you disable the REC balance cycle by bring it up to the same as your balance stop parameter so the two balancers do not try to fight each other

   

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