People tend to buy too large a generator, and then lament the awful fuel consumption. You are better off charging your batteries with solar, since safely charging with a generator only puts about 5% of the heat energy content of the fuel (in BTUs) into the battery for future use. A Solar chgarge returns up to 60% of the suns captured energy to you for reuse during discharge.
The "Choke Point" it is neither the rate the charger provides power or the rate the generator provided power. Rather it is the inherent inability of the lead acid battery to handle temperatures much above 115 degrees F. without overheating and destructive sulaftion occurring.
While I do use some effective battery additives to remove sulfation damage, it is very unwise to overcharge or over-discharge and intentionally allow sulfation to grow
Trying to pump more power into a battery above these temperatures just exasperates and compounds the sulfation problem, by causing even more heating and more sulfation damage.
This is truly a situation where “less is better!”
Most people buy an oversized generator and then try to minimize the run time by getting the huge 100 amp battery charger option.
They then try to “force charge” and “fast charge” the battery banks, and end up causing lots of battery damage by their own impatience.
Then they complain about constant premature battery failures, all the while failing to ever understand the root-cause and effect of the battery failure mode!
It seems easier to just over-rely on quick charges in the short term. The result is extremely costly repeated battery failures.
In would be really neat if Honda would add to the line of electronic inverter generators a some very tiny (100, 250, 500 watts) electric auto-start, fuel-sipping battery charging versions that incorporated the new ultra-capacitors so that the run time could be different than the charge time. They could then charge batteries, and power RVs properly, at a slow but steady charge rate that would not overheat the batteries, or conversely use too much fuel for long run cycles when battery charging.
These ultra-small generators would produce full power long enough to charge the ultra-capacitors fully then shut down the engine. Then ultra-capacitors would continue to run the generator’s built-in inverter to charge the batteries without need for the engine to run. Only when the ultra-capacitors ran low again, would the engine need to run occasionally to recharge the ultra-capacitors.
So the batteries would charge at a slow steady pace, from generator power just like they do from solar power. This would avoid too-high battery temperatures and battery damage and water loss from overcharging .
The Honda Engine would run sparsely, only when needed with huge attendant gas savings. And the RV lighting loads could float without constant battery charge-discharge cycles, thus greatly extending battery life from cycling as well.
Such a new Honda Generator could also be water cooled and the waste heat could then be employed for winter space heating, or heat adsorption chillers and year round domestic hot water heating.
Such a new Honda Ultra-Capacitor Ultra-RV Generator set would be well suited for RV’s 18 wheeler Condos, busses, trains and boats, disaster relief all manner of portable domicile applications.
RVers would be very wise to begin to demand such an efficient new battery charging generator product line from Honda and its dealers.
Meanwhile, there is nothing to stop you from extending your battery life and dramatically reducing battery recharge generator run times and fuel consumption.
The ultracapacitors are a COTS (Commercial Off The Shelf) product now!
I do not sell them, but I do recommend them and have just begun to use them, and plan to use many more in the future.
You can check out the new ultra-capacitors at:
and enter No 103 to see:
Ultra-capacitor banks from Maxwell Technologies (MC2600) rated at 16Volts DC. The cells are 2.6 VDC 2600 Farads each.
The cost is dropping rapidly and will soon rival/augment a good deep cycle battery system.
The rapid advances in the nanotechnology of reticulated graphite plates is creating a huge drop in cost and increase in capacity. Ultra-capacitors do not suffer from the temperature and charge acceptance of Lead acid batteries and someday may even replace them.
Even now, they can augment them and in a year or two they should become far more cost effective in doing so.
115 degrees F is generally considered the upper limit on battery temperature to avoid sulfation problems. I agree that it is way low for practical use, especially in the desert where ambient temperatures alone are often that high.
There is just so little margin for Ohmic heating from charging currents!
That is a principle reason for delivering a slow ad steady charge with solar cells or ultra-capacitor generators instead of trying to get all the charge suddenly into a balky electro-chemical cell.
Ridiculous as 115 degrees F may seem, that is the temperature where the knee of the sulfation curve lies.
So remember that millions of sulfated batteries are needlessly replaced every year from overcharging induced sulfation. If a $$350.00 ultra-capacitor (even at today’s prices) (with a 20 year life span) saves a $1000.00 bank of deep cycle batteries and extends their life to 10 years instead of 2 years, the savings become $4000.00-$350.00 for a net savings of $3650.00 over ten years. Note that battery changing labor not included, so the savings over ten years could be far greater.
Even at today’s prices, an ultra-capacitors combined with a battery bank to reduce ohmic heating and early battery demise is rapidly becoming a bargain.
While some folks might object that a larger generator might be required to run air conditioning, that issue is best addressed with a separate larger generator dedicated to cooling demand that runs only occasionally to save fuel. How do you make the Ac generator run rarely?
Most conventional RVs are poorly insulated energy hogs. a little more efficient insulation is far cheaper than continuous, endless fuel buys in the long run. If you are doing a RV conversion buy the best insulation you can!
Still, it is very hard to pack 18 inches of fiberglass in th walls to get to around R-30-R-40!
Since wall thickness subtracts from living space, super insulation becomes highly desirable.
Welcome to the space age!
Such insulation exists!
it is the fireproof, non-toxic NASA super-insulation called polyimide foam.
I do not sell it, but I do highly recommend it. It is not cheap, but is so much better it is a real bargain since only one thin inch gives up to an R-value of R-60!
you can find one spec sheet at:
Ever dollar spent on such efficient insulation will pay back hundreds of times over in extra living space and dramatically lower AC generator run times.