Chargeverter Plus deep dive. observations and suggestions

Hi everyone. I have a plan to deploy a stack of six Chargeverters so that I can charge my batteries quickly from a large generator. I am familiar with the "GC" model already, and I just bought a "Plus" to evaluate. I would like to share a few things I noticed.

I can see that the Plus is a complete redesign. The unit is larger overall, and the thermal design is substantially different. The DC cables are a little thicker. It is using a different kind of power conversion module inside, with one large fan instead of two small fans.

In the manual it shows the RJ45 pinout as having two pins labeled "PSU_CANH" and "PSU_CANL". I found that these allow monitoring of the internal status: temperature, fan RPM, voltage, current, etc. This will be very useful to me, as I would like to set up continuous graphing of all these values.

I tested the charger at various loads and it works basically fine, but there are some things I would like to mention.

One difficulty I'm having is that the fan never stops running, even when the machine is idle. I need these units to be idle but at the ready for thousands of hours per year, and that would mean a lot of unnecessary fan hours and dust pulled into the filter, not to mention the noise and power consumed. So I hope there will be some kind of revision that allows the fan to turn off when the unit is idle.

The fan is variable speed and runs faster at higher levels of power conversion. I noticed that the airflow felt low when I put my hand by the exhaust. At higher current levels, the fan RPM also periodically "hunts" up to a much higher speed and then settles back down, despite the electrical load remaining constant.

I inspected the foam filter on the exhaust side and noticed that the material is quite dense. I tried removing the exhaust-side foam, while leaving the intake filter in place, and this made a surprisingly large difference. Airflow was noticeably higher even at lower fan RPM, and the cooling behavior became steady.

For example, at a constant 62 A output, with the exhaust foam removed the fan settled at approximately 4,900 RPM and remained remarkably steady. With the exhaust foam installed, the fan repeatedly ramped upward, in some cases reaching approximately 7,400 RPM, and then fell back again. Output current remained essentially unchanged throughout this behavior.

This makes me suspect that the exhaust-side restriction is sufficiently high that the thermal/fan control system is hunting rather than reaching a stable operating point. I assume the foam may be related to the new IP rating, but it appears to impose a substantial airflow penalty.

I'm going to log the CAN telemetry over longer periods so I can get a better picture of the thermal behavior.

Overall, the product is very close to ideal for what I'm trying to do. If these issues are worked out, I would like to deploy six of them. The biggest issue for my application right now is simply that I need the fans to be able to turn off while the units are idle.

Thanks!

Sean