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**moosetags** · 11-14-2013, 12:48 PM

Color me oblivious because I never realized that there was such a thing as an Inverter/Charger. I would like to explore this option, especially in that this option is recommended by Lew Farber (lewster), a professional RV Technician who I know personally, and I respect his opinions.

Below is a is an excerpt from a post that lewster made on another thread.

"I was going to chime in on tis topic, but hesitated for fear of being accused of being too commercial…..but the dam has burst!

If you want the best (and I say this unequivocally) method of charging your batteries, replace your converter/charger with an inverter/charger. Just a few of the benefits:

• Full temperature compensation to properly control the charge voltage in a wide range of ambient temperatures
• Fully adjustable absorption times that are sized to the capacity of your battery bank
• Adjustable charge profiles that match the exact needs of your battery bank
• Full battery monitoring capabilities with the addition of a 500 mV shunt

Plus, you get the extra added feature of being able to produce 120VAC power from your batteries when off-grid.

An inverter/charger is light years ahead of any converter. It is an especially good fit with solar for off-grid use.

This being said, I would like to begin some dialog on the pros and cons of going to an inverter/charger the next time I am considering replacement of one of my converters.

Brian

lewster · 11-14-2013, 04:09 PM

Ok Brian……..you asked for it!

Proper battery charging is a science that has to accommodate more variables than any converter/charger (yes, even the Boondockers, Intellipowers and IOTAs which are 'dumb' compared to a quality inverter/charger like the made in USA Magnum Energy offerings) is able to deal with.

First, your charge voltage should be adjustable for the size of your battery bank. This is generally done by setting the time that the charger spends in the absorption charge phase (bulk, absorption, float).

Next, different types of batteries require different voltages for each charge phase to properly and completely get the job done. A liquid lead acid battery like an Interstate or Deka will require totally different charge parameters than a Lifeline AGM. Any quality charger should be able to set these charge parameters according to battery type.

Further, battery charge voltages vary significantly with the ambient temperatures of the battery being charged. The only converter/charger that does this is the Parallax Temp-Assure, which does not have a stellar reputation nor is it adjustable for the first two conditions. Quality inverter/chargers come with a temperature sensor probe that is connected directly to a negative battery lead (preferably one that is not directly conducting) to read the battery's temperature. This will allow the charger section to adjust the charge voltage up for colder temps and down for higher temps, according to the charger's internal charging algorithm.

Following these 3 requirements will give you the maximum battery life possible, assuming that you do not discharge your batteries lower than 50% on a regular basis, which will drastically reduce the number of available charge cycles.

Plus, with available remote control panels, you get to see current battery voltage, battery and internal inverter component temperatures and can also seamlessly add a full function battery monitor that reads thru a 500 amp shunt directly into the monitor panel…..no additional wiring required.

I have installed a few of Magnum's smaller inverter/chargers in primarily Airstreams where the folks do not even use the inverter section….they just like the increased longevity they will get from their battery banks now that they are fully and properly charged. Plus, they can become the first in a series of building blocks to a full solar charging system with enhanced battery bank for extended boondocking.

Questions?

Skater · 11-18-2013, 08:14 AM

We have one - an old Trace Engineering (now Xantrex perhaps?) 1500 watt monster. I was a bit slow on the uptake to realize it did both inverting and charging, which certainly explains why the camper starting acting normally when I turned it on when the batteries were run down after our first night of camping in the trailer. (As opposed to my theory at the time - turning on the inverter means the converter is now being powered, creating a loop... Later I found the switch for the regular converter.)

Ours has the ability to adjust voltages, temperature, etc., but it's all manual adjustment, which isn't a big deal for the battery type adjustments, but it is for the temperature adjustment - I'd have to get in there every few weeks and adjust the knob. And even then, with three batteries - two in the normal battery compartments under the couch, and one on the tongue - what temperature would I use? The batteries inside are very likely to be warmer than the ones outside...

I think it's probably a top of the line inverter for when it was built (mid-90s I'm guessing). It works well; we ran the microwave off it during our last rally. I usually use it for inverting only - I installed a PD9260 before I understood the inverter was also a charger. I figure, given the lack of automatic adjustment (especially for temperature), the PD9260 is probably doing just as well as the inverter/charger would, and I had a good experience with my previous PD9260 in the B190. I was also nervous about having to set the voltages. So I see it as a backup if the PD9260 ever dies.