Can I use my 135 Ah deep cycle battery to power a 2000 W inverter and at the same time charge my battery with a 50 A, 7 stage battery charger?
I don't expect to be drawing more than 300-400 W, 240 V from the inverter. Think of it as a home-made UPS for my office.
This is a normal situation in most boats (and probably RVs).
In my boat, I have a 450 Ah battery bank, a 2000 watt inveter, and a 100 Amp alternator on the engine. While underway, the alternator is charging the battery bank, while the inverter is drawing current from the battery bank to make 120 VAC to run my navigation computer (and any other 120V devices I may want to use) and also supplying power to various other 12 volt loads.
If the charger (alternator) can provide more current than the inverter and other loads require, the excess current goes to charge the battery bank.
If the loads require more current than the alternator can supply, the battery supplies the difference.
You can't really charge and discharge the battery simultaneously - although it may look like you are doing so.
As the charging source and loads vary, the battery will be charged or discharged as needed, changing modes automagically.
You can use it but it will confuse the charger in stage 4 absorption when the current does not decay due to the load and will respond with inappropriate recovery.
The charger must be able to remote detect battery current, which this does not do.
If possible Modify stage 4 with a timer instead to limit suitable time it takes to charge up the “Memory capacitance” which is the value that is often called soak charge which has a longer timer constant in seconds and minutes, vs milliseconds, . Remember a battery is just an array of capacitors in kilofarads , each with different values and different ESR and different Tau time constants.
But if leakage is excessive and detected as a battery fault in soak charge due to an external load, it cannot tell the difference.
for dumb chargers like automotive, it just keeps it at 14.2V for flooded cells so charge and discharge and battery SoC is irrelevant.
I do it all the time with a 4000 W inverter. I connect my inverter straight to the leads of the battery and run my inverter with the engine off.
If the battery starts to lose power I just start my truck for a little while. It runs the components that are hooked up to the 4000 W inverter and charges the battery. I do this routinely when I'm working in places with no electricity (which is frequent) and I don't want to carry a generator.
