Limit SoC from solar and alternator

AC300 2x B300. I have TOO MUCH power! I have a van with 300 watts of solar and the alternator charging it on the AC300’s DC1 & DC2. On a long sunny drive I hit 100% SoC. I would like to limit it to 80%-90% like the UPS grid setting but can’t find a way.

Hi @StanUbeki

Does your unit have a custom UPS mode? If so, you can activate this mode and configure the highest and the lowest SoC.



There are no settings in Custom UPS that limit SoC from solar/car charging. The manual makes several references to UPS SoC limits stating: “the remaining capacity will be charged by solar”. I am constantly reaching 100% SoC. To manage it I disconnect the solar/car charging.

Grade Idea i would want to have a SOC limiter setting on eb3a as well!
Hope they add it in a firmware update.

I don’t understand the “WHY” in this. What’s wrong with it staying at 100%? There is a “Charge Controller” in all solar generators. Their job is to control charging the batteries. There’s one in your car to keep your car battery from being overcharged. They are in all battery chargers, even in those that charge flashlight batteries. Battery chargers in general know when to stop charging, to avoid battery damage.
Now it’s a different situation if you’re talking about long term storage without any load. Then you simply disconnect it from all charging sources when it’s down to around 70-80% depending on the company recommendations. Of course, the problem with that is if you suddenly need it during a blackout and it’s not fully charged.

You can always use an on/off switch to disconnect it from the solar panels. I have DC circuit breakers on mine to switch the panels on/off. For this you need special DC circuit breakers, not the AC ones from Home Depot. DC will arc over inside an AC breaker. Btw, for a vehicle you should already be using fuses or circuit breakers for possible crashes and the resulting fire hazard. That’s why cars are so loaded up with fuses for every circuit.