Discharge order AC200MAX + 2 x B230: uneven discharging

Hi everyone,

I have a AC200MAX and two B230 batteries hooked up to it. Charging is mainly happening through 2x400W solar panels during the day. They are attached to the AC200MAX and charge all three batteries in the pack. On the consumer side (AC) I have attached a fridge (including a freezer compartment), which is supposed to be powered also at night.

I experience some strange discharging behavior, which does somehow prioritize the last battery in the pack over the former over the AC200MAX. Has anyone else experienced this uneven discharge behavior? For example, I started yesterday, after sunset, at a total of 85% capacity (100% AC200MAX, ~85% B230 1, and ~72% B230 2 - here it was already uneven) and this morning it was at 62% capacity (100%, 54%,29%). Wouldn’t it make sense to have an even discharge between the batteries? I mean, with the current discharge order it would be the case that, concerning the cycles, the last battery in the back would die first before the second one before the AC200MAX internal battery! I guess this is not intended…

Maybe this is something a firmware update could fix?

Best,

Andi

I don’t have the B230 or B300, however I have notice people complaining, when the AC200Max shut down, but wakes up with solar input in the morning. Apparently the other unit B230, B300 don’t wake up. You need to power it up manual.

So your other units will not charge up and/or not match your other units.

I would think this is an oversite and/or firmware bug feature.

I don’t think this is the problem. The AC200MAX never shuts down in my case as continuously power is drawn from the fridge.

I also noticed something else. Despite there is solar input (and it is shown on the display), the battery states do not change to “Charge”. It seems as if there has to be a certain wattage on the solar first before the state changes. Does this mean that for small wattages the batteries do not charge? For solely the AC200MAX, this seems not to be the case, only in combination with the 2 B230s I have. Anyone else experienced this?

The auto start was only with the B230 and B300, not the main unit. Which is one reason the unit are NOT fully charged in comparison to the mother unit.

If your solar panel is less than 10 volts or 12 volts for the ac300, then your battery won’t charge. With some cheap mppt, if voltage is too low it can start discharging your battery.
Even it is above 12 volts, it may wait until it much higher, above the battery voltage at least.

One reason why series are needed for some panel, the higher the voltage, the sooner it will start charging your battery. This will also start charging your battery in the early morning hours and in later evening hours.

I haven’t tested out the AC200Max to see if it happen, though I suspect it won’t (hopefully). When the rest of my equipment comes in I be testing all of these things that aren’t documented.

Hi aly, thanks for the information. I checked right now and the input is 11W over solar (it is evening now in Germany) at ~60V. I would have suspected that these 60V would be sufficient to start charging, but even the main unit stays on “Standby”…

One reason why some overpanel, play to get the best voltage balance. Victron only requires 5 volts.

Another benefit of that, it start charging your battery earlier in the morning and later in the evening. Longer day of charging, provided it not dark, too cloudy, no sun due to forest fires.