Gdetrailer wrote: (skipped some of his post--see original for full post)
"Personally, I suspect that your "test results" are highly flawed due to too many unaccountable "variables". You are using a lot of highly variable loads which potentially can skew your results.
Batteries present highly variability as does your inverter load on the battery."
Misses the whole point IMO. It is this variety that makes it so difficult to match the converter "size" to the generator "size" needed to run it for battery charging while camping.
My test approach is to do it in real life. As seen, you get different answers from using the converter as "supply" (less VA needed) from "battery charging" (more VA needed) Also true that it varies by battery type.
If you use a scientific fixed load to see what the gen can do, you miss the problem of just how much load your chosen converter will be when faced with your particular battery bank (type of battery, condition, wiring set-up, etc) at different SOCs.
Some converter makers also seem to rate their converters using an artificial fixed load, and publish misleading "specs" as a result, which understate the VA needed on a real battery bank.
In my case, I started with the actual VA this 75 amp converter required from my previous Honda 3000 on my actual battery bank (just under 1700) and matched that with the generator spec of 1700w continuous for my new generator.
I also thought being a "2200" it would have some margin above 1700. My Honda 3000 could do more than its rating without overloading.
It turned out as seen in this thread. Now that I know where it all stands in real life from using the Kill-A-Watt and Trimetric, I can decide what to do when that red light starts flashing, based on those real numbers.
Of course I don't like the word "flawed" there, but take comfort in seeing how closely Mr Wiz's results match mine with totally different set-ups except having the same model of converter. IMO this shows the measurements are valid.
You want the test to be what will happen when you are actually out there off grid with your batteries at 50% and you will be using your converter from your generator. Can it do it or not? Know before you go!
There still doesn't seem to be a reliable way to shop for a gen and converter to know exactly how they will match to get the most DC charging amps from the published gen ratings and converter ratings. It is expensive to get it wrong if they don't take "returns" on those.
You have to be lucky enough to be on this forum before you go shopping to get at least some notion about that. :)
