Lithium & 2nd Alternators Verses Onan Generators - Mike Mas

[dw8928]

No one has mentioned carbon Foam batteries that are available now. They have most of the deep discharge capabilities of Li.

I don't know if the rate of recharge is hugely different to regular AGMs. But they apparently don't die if you discharge them to zero. And they have the ability to be fine if left in low partial discharge for months/years.

And you just swap out for existing lead/AGM.

I was at the SpaceX launch this week at the Cape Canaveral Seashore. My Travato was HOT from the crazy infrared in FL and it was only about 80 degrees the first day I was there.

I traveled down from Seattle. But I know Southern weather very well and you NEED A/C. Genset is mandatory or the ability to really run the A/C with maximum output.

My 200 watts solar system has kept everything running fine so far. Except the AC and microwave.

I'm swapping to Carbon Foam once needed. I wonder if I could upgrade the inverter and power the microwave then?

[booster]

There is a discussion active now on carbon foam batteries


http://www.classbforum.com/forums/f2...ment-8990.html

[GeorgeRa]

Originally Posted by booster

I had an interesting conversation with an Onan engineer and developer when he answered a Craigslist ad for a chop saw of all things. Die hard tinker of neat stuff, it appears and he even has a functioning Stirling engine in his home shop. He as said there was really almost no chance of a small size RV generator redo from Onan and would expect the current on to discontinue if emission rules or sales dictated it. Too small a market. Whether other brands think the same is probably likely as nobody has jumped in and Onan is the only one left.
That said, in a small van I don't know if even a quiet Honda would be all that great once mounted to the van. You still have the exhaust to deal with and any noise and vibration in very close proximity. There likely is a reason a lot of DP class A's have the generator way in front and far from the daily life in the RV.
If you are in an area where noise isn't and issue, from a livability in the van point of view perhaps a remote generator would actually be the best if it could be made more convenient for storage, moving, fueling, etc. At least you wouldn't have it in a tin can with you while in use.
I would agree that the alternate energy sources are biggest hope for better solution for those that use lots of power and need AC as none of the existing technologies are all that great.

It is unfortunate when management sleeps at a wheel while competitors sound alarms, recovery can get difficult. Photographic cameras giants like Canon or Nikon slept while a fresh comer Sony, after acquisition of Konica/Minolta, shook the market with the full frame mirrorless offer. Sony fully understood the benefits of mirrorless technology while Canon and Nikon were grounded in their DSLRs film age derivatives still juicing good profits. Now Sony can automatically focus on an animal closest eye, a technical advantage of the mirrorless and impossible with DSLRs. Canon and Nikon are trying to catch up, I wish them best.

Back to Onan, I think market is hungry for 500-2500W, silent, small, RV mountable power generator. A combo of a small generator with a proper size battery bank should fulfill AC needs. This hunger is visible by interest in fuel cell devices, silent, small, RV mountable but reliable LPG fuel cells still need to be invented. As far as I know all fuel cells must use very clean hydrogen, so all hydrocarbon fuels need to be converted to H2 and CO2 first and this is a fundamental issue with fuel cells for the RV market.

My last Onan was still slurping oil with a scoop, that is an antique oiling method in the combustion engine world. I don’t have numbers, I am retired, but I think there could be business justification to develop a small, silent, LPG generator for new RVs and for upgrades. Business calculations are reasonably easy if no inventions are required, there are none technological red flags.

But, I very much doubt that Onan will be coming out from their nap without a very loud alarm.

[booster]

When you look at the number of class B's sold, there really isn't any way that I can think of to tool up, even with modifications of standard products like Honda or Yamaha could do, and make it profitable. The larger Onans are used on lots of places other than RVs, and in many more RVs than are sold as B's, so they can support more support, if that makes sense at all.



If there is a new, small, generator made it will need to have other markets like tent and trailer campers and some other now unknown low power use segments like maybe power for recharging battery operated lawn products. I don't think it will be IC engine in the traditional sense, but maybe a Stirling style external combustion linear generator, so such, but I am just guessing.

[RossWilliams]

"Specifying battery capacity in Watts is totally a fiction"

No, it isn't. Its actually a clear and accurate estimate for anyone who wants to understand how to manage the power for their RV. I don't really care whether it offends the sensitivities of small-minded engineers.

"9600 watt hours or 800 AH at 12 volts or 400 AH at 24 volts all are valid capacity specs"

AH is a "capacity spec" only if the rate of discharge is described in that spec. You can find all sorts of batteries on Amazon with very high AH that are based on very low current draws over extended periods of time. They aren't really meaningful.

You can also find all sorts of batteries on Amazon with the AH specified and output ports for 120 volt, 12 volt and usb. That obviously tells you nothing about how much power you will get from it at 120 volts.

"9600 watt hours or 800 AH at 12 volts or 400 AH at 24 volts all are valid capacity specs for your eTrek 8 x 6v x 200AH battery bank which is wired as a 24 volt battery bank with a tap at the middle of the bank to provide 12v power."

Or you could just say "9600 watts" and have all the information you really need. Basically this silly argument boils down to a belief that it is blasphemy to shorten watt/hours to watts in non-technical descriptions of batteries. Count me as a heretic.

[avanti]

Originally Posted by RossWilliams

"Specifying battery capacity in Watts is totally a fiction"

No, it isn't. Its actually a clear and accurate estimate for anyone who wants to understand how to manage the power for their RV. I don't really care whether it offends the sensitivities of small-minded engineers.

"9600 watt hours or 800 AH at 12 volts or 400 AH at 24 volts all are valid capacity specs"

AH is a "capacity spec" only if the rate of discharge is described in that spec. You can find all sorts of batteries on Amazon with very high AH that are based on very low current draws over extended periods of time. They aren't really meaningful.

You can also find all sorts of batteries on Amazon with the AH specified and output ports for 120 volt, 12 volt and usb. That obviously tells you nothing about how much power you will get from it at 120 volts.

Basically this silly argument boils down to a belief that it is blasphemy to shorten watt/hours to watts in non-technical descriptions of batteries. Count me as a heretic.

You are very, very confused.

[RossWilliams]

"You are very, very confused. "

Not at all. The people who are confused are the ones that think this is a technical engineering forum or have treated it as such.

BTW, you are the one who stated your battery capacity elsewhere in Amp/Hours. How is that meaningful without stating the voltage? Was that at 24 volts? Or 12? or 6 volts? And what rate of discharge was that AH measured?

[booster]

I guess heretics also don't realize that any watt-hr rating is also based on a discharge rate in hours, just like AH so no better at all in that respect.


I guess you could say watts take the time of discharge rate out of the picture, but it is only because watts is an instantaneous power rating so no time is involved at all. Of course it tells you nothing about the energy capacity of anything.


Shortening or abbreviations are fine if they still define what you are talking about, but watts don't do not mean watt-hrs and mean something else when used alone, so totally useless as a shortening. Watt-hour can be abbreviated to W-hr and then what you are talking about is clear.



It doesn't take a panties in bunch engineer to figure this out, it is more of an English language thing that pretty much any grade school kid could understand.


Methinks Ross just decided it was time to ruin another thread with a bunch of contrarian nonsense.

[GeorgeRa]

I deleted my post, don’t want contribute to Ross dilemma.

[RossWilliams]

Let me clarify for you. Watts when used for battery capaciy is shorthand for watt/hours. I know that is hard to understand or accept and is heretical to the engineering religion.

AH is not useful in an environment where some appliances are 120 volt and others 12 volt because 5 amps at 120 volts is 600 watts and a 5 amps at 12 volts is only 60 watts.

AH is not useful in any environment unless you know the battery voltage.

AH varies according to how it was measured and if you want to always use technically accurate engineering specs, then you need to state that rate.

By contrast watts (or in engineer-talk watt/hours) is a meaningful measure of capacity for an RV that allows one to simply determine how many watts an appliance consumes to determine how long your batteries will last. That 1500 watt microwave consumes 1500 watts. Divide your 9600 watts by 1500 and you will get the roughly 6.5 hours your batteries will last. That 100 watts the inverter consumes is 100 watts. Your batteries will last 96 hours. It doesn't matter whether you know or care what voltage it uses.

Of course you still need to consider how far you can safely drain your battery. You also need to consider that drawing a battery down in 6.5 hours is much faster than the 20 hours usually used in determining its spec so you will get less total power.

You want gobble-de-gook here it is:

"800 AH at 12 volts or 400 AH at 24 volts all are valid capacity specs for your eTrek 8 x 6v x 200AH battery bank which is wired as a 24 volt battery bank with a tap at the middle of the bank to provide 12v power."

That isn't really at all helpful to figuring out my energy usage. If I have a 1500 watt air conditioner, how long will it run?

[booster]

And the typical name calling begins, just another like all the others times when Ross showed up and didn't hear what he wanted.

[hepcat]

Ummm... so how many watts does a gallon of propane have?

Measured with a micrometer, marked with chalk, and cut with an axe.

I'm always amused by these conversations.

[GeorgeRa]

Originally Posted by hepcat

Ummm... so how many watts does a gallon of propane have?

Measured with a micrometer, marked with chalk, and cut with an axe.

I'm always amused by these conversations.

Wrong units, 1 gal of LPG means LiterPerGalon so 1 gal is 1 l

[avanti]

For the non-technical driver:

schoolzone.jpg

[booster]

Originally Posted by hepcat

Ummm... so how many watts does a gallon of propane have?

Measured with a micrometer, marked with chalk, and cut with an axe.

I'm always amused by these conversations.

Actually you would measure it with a "propane-ometer".


And then leave off 1/2 the unit description that is listed on propane-ometer.

[Davydd]

Having been accused of not knowing what I am talking about in amps, ah, watts, volts, etc. I will reluctantly put in my 2 cents. Most a B vans have 12 volt batteries or deliver somehow in 12 volts so amp hours have generally been understood by just about everybody, even the dyslexic electrical challenged like me. When Roadtrek started boasting about watts it was hardly understandable but the impressive higher number must have impressed someone. Until Volta came out with a 48v system in a B did I have to pay attention to watts because I had to know how to translate it to what I am used to. But it translates like millimeters to inches to me as I have to go and calculate it all out laboriously by hand not in my mind.

[gregmchugh]

This is so ridiculous, clearly Ross has no real interest in understanding anything beyond his preconceived notions of pseudo science.

And, When did “watts / hour” become the same as “watt hours”?

For us small-minded engineers who have actually done real engineering as a profession this stuff makes all the difference between landing on the moon and killing off a few astronauts. Or, maybe we never really landed on the moon and it was all fake news.

Time to once again treat Ross as a troll and just stop responding to his nonsense which simply encourages him to keep up the argumentative diatribes. When you can’t even deal with the need for precise measurement unit definitions how can you have any meaningful technical discussions. Life is too short to deal with his BS...

[RossWilliams]

"this stuff makes all the difference between landing on the moon and killing off a few astronauts. "

We are talking about the best way to measure battery capacity and use in an RV. I think our astronauts are safe.

"Most a B vans have 12 volt batteries or deliver somehow in 12 volts so amp hours have generally been understood by just about everybody, even the dyslexic electrical challenged like me."

Except the people who plug in their 15 amp heater overnight and discover that an amp at 120 volts is not the same as an amp at 12. Or a hair dryer or ...

You are right that AH is perfectly appropriate for comparing batteries at the same voltage. But it does a lousy job of clearly telling people how much power they can use or are using.

[GeorgeRa]

Originally Posted by gregmchugh

.......................
Time to once again treat Ross as a troll and just stop responding to his nonsense which simply encourages him to keep up the argumentative diatribes. When you can’t even deal with the need for precise measurement unit definitions how can you have any meaningful technical discussions. Life is too short to deal with his BS...

There is big difference between knowing enough to understand basics and ask questions if in doubt versus claiming expertise but not knowing enough to understand like Ross.

[gregmchugh]

Originally Posted by GeorgeRa

There is big difference between knowing enough to understand basics and ask questions if in doubt versus claiming expertise but not knowing enough to understand like Ross.

Whether he understands anything technical or not, he is still simply a troll in my mind with a goal of creating havoc by repeating the same BS over and over again with no regard for whether it has any basis in fact or is a reasonable addition to the discussion. Responding to him simply extends the length of these back and forth comments with no end in sight since he will not change his mind and we will not accept his crazy interpretation of technical issues...