So for all these years Fun Bus has only had a group 41 house battery under the drivers seat with a simple relay for charging while driving and no means to charge while in storage. Since last April I have been primarily using the 91 van for daily use and the Florida trips. The house battery drained during winter last year and went bad. Did the same this year during the virus thing. So looking for an inexpensive charging solution I also considered a small inverter. I came across this.
https://www.amazon.com/soyond-Inverter-Modified-Converter-Off-Grid/dp/B07W5YTTTF/ref=sr_1_18?crid=OFTR4XABIM5P&dchild=1&keywords=inverter+charger&qid=1587910620&sprefix=inverter%2Caps%2C158&sr=8-18

So I have one here and have set it up in the garage for some testing. So I don't always trust ratings but with 100 A/H battery this thig will support a 1,500 watt heater. For the price, cool. It has a transfer switch for the outlets. Plug it in and the outlets go to the inlet power. Pull the plug and it quickly transfers back and the inverter picks up the load. I need to do more testing but it looks like the transfer switch also connects the outlet neutral to ground in inverter mode. Wow.
For the charger section it does deliver just over 15 A/H and charges to an indicated 14.2 volts. Manual says it should go to a float mode. 2 days and still at 14.2.

This unit does not have UL ETL, CSA listings on it and for RV use it should probably also have a GFCI. I plan to only use for direct plug in of double insulated appliances. It does not seem to be designed for hardwire installation on the 110 volt side. It has an LCD display that offers little information. No load or current information. Just volts in, out, status. There is a port for a remote display but I haven't found one yet. Product is probably very poorly supported.

So my plant is to install this and replace the charge relay with an ACR.

Dennis