Generator Fuel Consumption

[Jon Wehrenberg]

Geoff,

I'll piggy back on what Peter said. The charge rate of your inverters or converters also contributes to determining how long it takes to charge your batteries.

But to address the question of why run the generator, I think it is a matter of preference. I do not rely on auto start. I prefer to maintain a higher charge in my batteries than the auto start is set for so I run the generator often for two reasons. The first is to keep the battery voltage level in excess of 12.3 or 12.4.

But primarily the reason is I want to use all the features of my coach. If I wanted to conserve I would buy a tent. I run my generator in a rest area if we are going to stop for a long lunch. I run my generator in a rest area if we stop for the night from the minute I shut down until I go to bed. I want to run my airs, or my heaters, or every appliance we have on board if I choose and I don't want to "manage energy". If I was spending a week at Quartzite (that ain't never going to happen) I would be conserving energy.

[Petervs]

Interesting post Jon.

We do the exact opposite it seems.

First off, I dislike hot places, so we rarely need the AC. The house bank is plenty adequate for everything we use in the bus for an afternoon or evening stop. We do need the generator for a little while if we happen to use the cooktop which only operates on 220 volts. If we run the generator for that for a half hour or so, that again tops up the batteries.

If it is cold out, we have the Webasto running, it keeps us very toasty and is way more efficient than running the generator and the heat pumps or the toe kick heaters.

We often have the windows open when we stop, generator noise would then be a negative.

The big alternator on the Detroit charges the batteries way faster than the generator. I see 90 amps going into the batteries from the generator, and 270 from the engine. I see no reason the batteries need to be fully charged if we are planning to drive anyway.

I often run the generator a while longer than we need it just to get it warmed up thoroughly not so much because we need the power.

Neither way is better, just depends on your style I suppose.

[Jon Wehrenberg]

Peter, this goes back to our original bus that had a manual selector switch instead of an automatic transfer switch. After 15 years of ownership Di still had a hard time remembering what position the black selector knob had to be in to make a cup of coffee or watch the TV.

So for simplicity sake I just cranked up the generator and the selector know was switched to "generator". That way Di did not have to think about anything and she could use all the outlets or do whatever she wanted. When we were plugged in she just had to switch the knob to "shore" power.

While this coach is virtually all automatic with the automatic transfer switch and auto-start there are still things that do not run through the inverter, so to avoid even the slightest inconvenience I just run the generator. After all it is a luxury coach right?

[bluevost]

when we boondock in Quartzite I run the generator about 4-5 hours a day. In the morning to warm the coach up and fix breakfast, and again in the evening to fix dinner and charge the batteries for the night. We are usually at the swap meet during the daytime. I never hear the pitch of my generator change, it runs at one constant speed no matter what is turned on. It is a power tech, 17.5 kw. I figure .8 gph and that's pretty close. So maybe 4 gal per day. If we have everyone inside watching football, I of course run it during that time, and the numbers change slightly.

Question to anyone -- Can you run the Wabasto off the inverters. I have 2 Heart 2500, and 8 4D batteries, that just turned 2 years old.

Jon -- Come to Q for 4 days instead of a week!! I hear there is a fresh water oyster farm on the Colorado River.

Happy New Year everyone,

Ken

[Petervs]

Ken, YES you can run the Webasto from the inverters, actually, the inverter is not even in use, it just runs on 12 volt battery power. That is the whole point of having the Webasto.

If the generator was running, you could use the heat pump AC/heat but that would use more fuel and make more noise for the same heat output.

Jon, I suppose you are still driving stick shift cars so you know what gear you are in? Come on now, you really can teach some old dogs new tricks, the only thing you need to do is forget some previously learned habits that are no longer necessary.

Try not running the generator when you stop one day, you will not die, no less comfort will be felt by those in your coach ( unless you need AC) and all of a sudden that warm glowing feeling will come over you because you have now saved some fossil fuel and are delaying the global warming process by a few minutes.

Try it, you'll like it!

[lewpopp]

Ken,

Are you sure you have 8- 4D batteries and not 6- 4D batteries?

[truk4u]

The worse thing you can do is to not run your gen long, hard and often. Powertec explained to me in detail, "you bus guys with the big gens don't use them, they're designed to run 20,000 plus hours before overhauls."

I dry camp often and if not real hot and don't need the air, I do the same as Ken, run in the morning and again in the evening and I always let the chargers get to float before shutting down. You can't top a battery bank unless you get to float!

Like Jon, I won't use the auto-start while dry camping unless it has the capability of starting at 12.2 volts.

This thread is going to get real interesting!

[rfoster]

I am convinced global warming is over, oil/gas prices are down, I am running the generator and when I grow up I want to be like Jim Keller.



Flying J-- Knoxville fuel $2.19.9 gal. Sunday night.

[Coloradobus]

We run our generator all the time, all the time when dry camping. In National Parks we run it the entire day before quiet time sets in.
At the flying J, we run it all night from the moment we stop for the day.
Kohler, like the Power Tech guys, and Marathon (Leon), have over and over lectured us to RUN the genset.
We Rarely use the Webasto, now. I wish we didn't have one. Superbus1 doesn't use a Webasto or like product, their coaches are completely electric.
After seviceing our Webasto recently (been 2 years of running only to assist for hotwater), (Jon pointed to our smoke in Spearfish), we needed a new burn tube and ofcourse a nozzle and filter.
Nozzle was $14.00, burn tube was several hundred dollars from the source,(we live 35 miles from Vehicle Systems/Aquahot.) For the money spent on Webasto parts, it wiould take a many hours of running the genset to burn that much diesel.
Our cruise airs, and definitely the Webasto, makes more noise than our genset. We were even accused of running our genset during quiet hours one chilly Yellowstone night by the campground host (nazi), We needed a civil assist from the Grant Village local Ranger to help prove the noise from our coach was from the Webasto, and not the genset. since that time, we don't use the whining Wesbasto.
We often ask ourselves why Marathon installs 3 different froms of heating in the coach, its more cost, more weight, and more maintenance.
As Jon said, if you don't use the genset and really make it work, it will carbon up and not run well.

[Jon Wehrenberg]

Peter,

I believe you are catching on. The two vehicles I drive almost exclusively are manual transmission, and if I had my way the bus would have one also.

Automatic stuff is for sissies.