Originally Posted by ollison
I am new in the motor home world and have some mechanical knowledge but weak in the electrical world. I had and older Heart 1800-12 inverter that was not It had a shut down warning light and I found another heart inverter on Ebay Older new stock unit that seemed like a good buy at $599. Looked new. Hooked it up and plugged the 2 110 volt plugs and watched the shut down light and presto it stayed on. It did put out 110 volts. 2 problems have showed up. 1) I find it shut down after a day or 2 so I reset it once again. 2) My new batteries are failing to charge. I didn't notice anything until I pushed the monitor button. Said batteries are weak. doesn't the inverter charge the batteries? Also all 4 of my batteries appear new. It starts strong. But my step is slowing down. Another question is which batteries are being monitored? I have 2 that can be accessed from the outside. Are these the cabin batteries? I have 2 under the bed inside. Right now I'm charging the 2 on outside with a charger to see if the monitor changes. Please give me a run down on this system. Next to my heart inverter is a unit that buzzes when plugged in. What is charging the batteries? I don't see how this inverter charges anything. Hooks up to 12 volts and sends 110 to plugs. Sorry to be so inferior in my knowledge. I only have about 3 days to send this unit back. I would rather not spend $1000 plus on a another one. It does look new.
I"m not familiar with this inverter and can't find specifics on it. However, if there is not a 120v line running TO it from the coaches system, then it doesn't charge the batteries. It simply takes 12v from the batteries and inverts to 120v. So my theroy is your converter/charger is not charging the batteries. When they get low, the inverter shuts down.
Assuming this is a diesel, the rear batteries are for starting and the fronts are for the coach. When plugged into shore power, the charger should charge those batteries and they should show 13+v. If less than 13v, the charger is not working. That buzzing box sounds like the charger. It will have a 120v line in and large 12v cables out that lead to the coach batteries.
After charging with an external charger and the inverter works again, this would indicate the onboard charger is not working (as long as it was plugged into shore). That's about all I can help with at this time and is just the basics.