I have a Smart Solar 100 | 20 charge controller which gets power from a 165W panel. I also have an IP22 charger which connects to the battery via the same bus as the charge controller. The battery is a 100Ah Battleborn lithium, and on the negative of the battery I have a SmartShunt installed.
When not connected to mains, getting only solar power, the charge controller powers loads first, and uses extra to charge the battery when necessary, otherwise it cuts power from the panel. With sufficient sunlight, most of the time it just feeds about 9W of power to cover parasitic draw from a few devices in my RV that always run. The battery just stays at 100%, unless the sun goes down or behind a cloud in which case it draws from the battery. When charging, the solar charge controller starts at a relatively low voltage and ramps up slowly, until the battery is almost full, then it ramps up pretty fast until it peaks at 14.5V (configured), holds it there for 30 min, then drops to 13.5V. The SmartShunt is configured to recognize anything above 14.4V for 3 minutes as an indication of full charge. This is all great, just exactly what I expected.
But it is completely different on the IP22. If I take the solar out of the equation by cutting the panel off, the IP22 charges the battery by immediately raising the voltage to 14.5V and holding it there until it determines (presumably by current) that the battery is full. Then it holds for a bit (not sure how this is configured), then drops to float voltage (configured as 13.5V) and then drops a few hours later to storage voltage (configured as 13.5V). For whatever reason, this is not enough to convince the SmartShunt the battery is full. So the SOC value drifts over time. This is the first problem I'd like tips on solving.
The second issue is how the IP22 handles load. By which I mean it doesn't, really. At least not small loads. The 9W draw comes directly from the battery, and after some threshold is reached the IP22 wakes up, adds power to the battery, then goes back to sleep. It spends a lot of time cycling quickly between the different profile steps. This process seems to work, I guess, but it's a bit ugly to watch in my Grafana plots, and it seems much less elegant than the way the solar charge controller handles the mix of load and charging. I'd like to know if this behavior is configurable, or if it is inherent to the design of the IP22.
In my perfect world the IP22 would have a battery profile that looked a lot like the solar charge controller would look like with perfect sun at maximum capacity. And the SmartShunt would correctly reset to 100% SOC regardless of which charger tops off the battery.
Please, if you have any tips on what I may be missing here, I would sincerely appreciate it!