One other thing that was probably operating is the converter/charger. Depending on what state of charge the batteries were in (like low, as if used overnight) you could be taking up to 1000 volt-amps with it alone. I say volt-amps, as the modern solid state switching converter/chargers have a very significant problem with power factor, making the load the generator "sees" much higher than the watts that we usually calculate. The Honda's are actually rated in volt-amps output, not watts, and although in many cases they are the same when the power factor of the equipment is low, you can think you have a load within the capacity of the Honda, and in fact you are not.
I ran into this with a Inellapower 9160 (60 amp output) when trying to use in on my 1000 watt Honda inverter generator. It was the only load, so I figured that even at full output of 60 amps 13 volts it would be under the generator rating. 60 x 13 = 780 watts, some inefficincy, maybe 800 to 850 total. Well, the Honda triped out. I finally put my Kilo-Watt meter on the converter, and set it on Volt-Amps scale. (not watts). When charging an almost dead battery set, I fount that the converter took something like 1150 volt amps, which is over the max 1000 that the generator is rated for. Now, on watts scale, it appeared to be around 800 watts, but the Honda "saw" it as 1150 volt-amps.
So, once again the world is more complex than we thought. Power factor and volt-amps vs. watts, while not often an issue, can be involved these days with equipment which has switching power supplies. That includes many kinds of electronics. Even your TV and DVD player may take more than you think, when you actually measure their volt-amp draw.
Ah, for the bad old days, eh?