Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
This is a very good (shall I say obvious) Point that no one raised. Manual Button needs a body to push it. that's OK BUT what if the Body is away.And then what happens when your BMS decides to turn off on safety protection? You have to add that ritual into your routine every time you reset it?
Now you cross another area of Foibles as well.
* Relay/Contactor BMS' obviously can be handled by using the relays and even a Timer Relay that can bypass and trickle that precharge in. There are a few methods posted in the forum and on YT that can work. This is another advantage of having a Relay Based system, gives a few options to "be creative". (Ohhh boy Deja-Vu 2019). This is partly why Chargery developed the DCC Solid State Contactor with the precharge circuitry built-in.
* FET Based BMS' on the other hand, cannot be accessed in the sense of taping into its circuitry, and who would take a Soldering Iron to their new BMS ? So we are left with a Manual Switch or a Commercial/Retail auto-switch (crazy cost) and not a simple solution to just go buy a "quick kit". And just to further complicate things, if you have Multiple Packs within a Battery Bank now you have to deal with it at the BUS Level as opposed to the Battery Packs individually.
A Question for the Extra Savvy, some on YT just leave the resistor in-place all the time so there is always a constant "trickle" if you will, I suppose that may be OK if it's fused but I dunno how I feel about that myself.
I am now in process of my final redesign / build which also involves replacing my entire fleet of BMS', including my Utility Packs to the JK-BMS with Active Balancer (no relays/contactors) and of course no Pre-Charge circuitry. I have reached out to https://www.jkbms.com/contact/ asking about how they suggest handling the PreCharge requirement and asking as to why this "essential" feature is not Built-in already.