Yikes! What have I gotten myself into? How many times have each of us said THAT? In my case, once I finished our solar project, I turned my attention to how to use certain small appliances that require 110 volts, while running off of the battery bank. For no reason, things like hair blowers and curling irons came to mind. Oh ya, and maybe a coffee pot or TV. And, of course, techie things like laptops, Kindles, and such other gadgets and their associated chargers. This lead me to research, thoughts and an eventual purchase of a inverter. In this case, a Xantrex Prowatt Pure Sine Wave 2000 watt inverter.
Of course, one thing leads to another. You can’t have an inverter without real heavy-duty cables. In my case, I went with 2/0 custom cables from inverter to battery bank, in this case, 4 footers. And then there is a 250amp circuit breaker to go inline
So that takes care of the inverter-to-batteries side of the equation. What about from inverter to DC distribution panel? Well, this is where one thing leads to another…again.
In my research into inverters, one of the things that was pointed out was the fact that if the CONverter was allowed to operate as usual, and the INverter was connected to it, a loop would be created the result of which would be rapidly discharged batteries. It has to do with the CONverter converting 110 volts to 12 volts, while the INverter converts 12 volts to 110 volts.
So anyway, I came across an article that offered a few ways to wire up an inverter. One suggested solution involved two additional ingredients. First, was a 30amp receptacle wired from the inverter to be mounted on the outside of the motorhome. The other was to wire in a relay between converter and inverter. The idea is that you would use the shore power cord to plug into the receptacle. And when properly wired, the relay would detect and turn off the CONverter when it senses that the inverter is in use. This had the added benefit of allowing for the use of existing electrical outlets in the coach and, ultimately caused me to favor this option. And, of course, at this point I was knee deep in “one thing leading to another”.
All of this quickly lead me to realize that my factory installed converter, although trouble-free, was woefully inadequate by today’s standards. It wasn’t so much the converting part, but rather the charger part. Converter/chargers of the day back when my Bounder was built were essentially “single-stage”. This is a reference to the battery charger portion of the converter. When plugged in to shore power, you got a specific level of charge in an effort to recharge the batteries. This effort could take more than a day, or at least the better part of a full day, and even then you would likely only be 90% charged. If you unplugged in order to get out on the road, you might not have received sufficient charging.
Since I was going to be accessing the old converter/charger for the purpose of wiring in a relay, I had to seriously consider upgrading to a new state-of-the-art version. An “upgrade” of the converter would get new technology in a smaller and lighter package AND get a multi-stage “charge wizard”, also sometimes referred to as a smart charger. Not only will the batteries be charged much faster, they will also be charged in a series of “stages” involving different voltages and amperage to insure the overall health and longevity of the batteries. I ordered a new Progressive Dynamics Intellipower 9245 45 watt converter with built-in “charge wizard” multi-stage charger. One thing leads to another.
To be continued…