Power up issue when using Li-ion battery - DC1836-A (LTC2955)

I tried powering DC1836A-A from my batteries and I could not replicate the problem you are seeing.  My battery packs make around 18VDC.  Hot-plugging an input supply can cause voltage overshoot that can cause electrical stress-type damage, but I am not sure why hot-plugging would cause intermittent operation.   

I tried powering DC1836A-A from my batteries and I could not replicate the problem you are seeing.  My battery packs make around 18VDC.  Hot-plugging an input supply can cause voltage overshoot that can cause electrical stress-type damage, but I am not sure why hot-plugging would cause intermittent operation.   

Thanks for trying this, here is my theory:

I think what is happening with my setup is that the 4-cell battery pack BMS is detecting the over Voltage and cutting itself off from the load. In the battery pack data sheet it mentions "over charge voltage detection" as being 4.325 V +- 75 mV (per cell)... so just 17.3 V would be enough to trigger this, but it is not specified over what timeframe. The over Voltage duration when hot-plugging the battery in my case probably just about exceeds the threshold of time for BMS cut-off, which would explain why it sometimes powers up OK with multiple attempts.

I've made a circuit with some passive components to reduce the transient voltage, once that arrives I will test and report back.

Thanks again.

The issue is related to the BMS of the battery pack I am using, I managed to reduce the voltage transient using electrolytic capacitors, but then the issue of inrush current also causes the BMS to cut off the battery from the load.

So, I need to do further design work to also limit the inrush current and prevent the BMS from "tripping".... but that is a different issue, not related to the eval board :-)