Extension battery modules for ac200

Ac200 is really versatile and it can power virtually all RVs except the limited 1700W capacity. I wish Bluetti can come up with a battery extension module which can be DC charged by ac200 or DC charge into ac200. Each module can be, for example, either with 500W or 1000W capacity. Although one can achieve this use case by buying more units of ac200, cost is one thing, the problem of total size and weight could be prohibitive for a class B RV. If anyone knows another cost effective way to achieve this, please let me know.


Other than the weight of the battery’s,I use a 24v growatt (under $800) Unit.
It has all that bluetti has with but external battery’s. bluetti ac200p has a 2000 watt inverter and the all in one Growatt 3k has a 3000 wat inverter.
I bought the bluetti as a back-up.