Jury-rigged generator needs and expectations?

David: So let me try to clarify what you just said. Lets say each of our batteries have a “cold cranking amps” of 100A and a “Hot cranking amps” of 200A and we have 4 batteries in the bank. Each battery wants 10% of the 200A rating, AKA 20A, correct? Since we have 4 batteries, we would want to dump 80A (4*20A) into the bank to give optimal charge to this particular bank?
:EDIT: Does the optimal charge rate change with temperature variations? IE, when cold each battery would want only 10A so 40A for the bank?

Hi Brian, you have the math down cold. The terminology is a little off though. You would want to know a battery’s total capacity in amps to do the calculation. Try to get away from “cold crank amps” when talking about deep cycles though. If a battery feels obliged to list cold cranking amps or minutes of reserve then chances are it’s not a true deep cycle. As a ball park figure the golf cart sized batteries average 50 amps at 12 volts so a bank of 4 would have a c10 rate of 20amps. You can cheat that for the first little while but that is the rule of thumb. About temp: yes a good charge controller monitors battery temperature and adjusts current accordingly. This is really bare bones here. Everyone has a secret sauce for charging and there are great battery maintenance guides out there.
Check out www.microcogen.info for more on that
Check out www.balmar.net for info on alternator charge controllers…

David and Brian,
Yes the battery in question would be a deep cycle (trolling motor battery) It is my understanding that some car altenators have the a regulator built in them and some don’t. With the resistor setup I’m thinking one would not want a regulator-in-altenator designed for a car battery when charging a trolling motor battery bank? What exactly is a “simple resistor on the field” I’m very interested in this resistor setup. I’m familiar with wiring things together but when it comes to resistors, diods and regulators and what to buy and where to put them, I don’t have much experience with. Is the resistor on a switch? IE “Jury rigged senario”. so after a certain amount of bulk charging as the operator one would manually throw the switch to a trickle charge (top up) the battery bank?
Edit: David didn’t see your last post before I posted reading links now - thanks

home Power magazine published a great article about this kind of generator when they were still a magazine about making things instead of one about just buying things… See the link here: www.homepower.com/sites/default/files/uploads/.../mark8.pdf Great article, Great magazine (in the day) taught me everything I know… (sometimes that feels like very little)

David, got to homepower.com but could not follow the link.
Curious to know your thoughts of this link.
A little off topic but if it does what they say it does it could save a battery or two.
Seems to be a whole different charging concept.

My bad, try this one: https://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&ved=0CFkQFjAG&url=http%3A%2F%2Fwww.homepower.com%2Fsites%2Fdefault%2Ffiles%2Fuploads%2Fwebextras%2Fmark8.pdf&ei=m70uUf_aOYK8yAGihYGYAw&usg=AFQjCNFSSinc1_FuS_mj2lM9RAjsn6dzwA&sig2=WtkyXcTaagzdtdXrsZukog

As to the link above I find that anyone who has to use Tesla’s good name to sell you something is usually trying to scam someone. Plus there was a pop up, I hate pop ups. Go a little deeper and they use all the catch phrases that set off my alarm bells. I would not be surprised if in that over priced package there isn’t a standard charger of some sort with a different bell and whistle but veiled in mystical language… Unproven, Unprovable “THEY” don’t want you to know about with lots of testimonials in no way quantifiable… They take a small fact; most cheap chargers are junk; and build a conspiracy around it. There are great chargers out there just not cheap ones… You just need to find one that monitors the battery and controls charge rate. Just one person’s opinion of course…

I was on the fence about buying one for just that reason (using Tesla’s name) but needed a second opinion - thanks - while I am a Tesla fan it is sad to see his name dragged through internet sensasionalism.

Awsome homepower link - that’s definitely one for the favorites / save button !

Hi Guys
David Baille I am SO GLAD you posted up that old very excellent Homepower article.
Saves so-o-o-o many words.
Nothing much changed guys for practical application of “Jury Rigged Generator Needs and Expectations”.
You WILL be using some kind of flooded lead acid battery.
Only three types readily, cheaply available:
Quick burst engine starting capable types auto or truck; true LOW L-o-n-g power in and out golf cart types; half n’ half, compromise “deep cycles” used on pleasure craft/light fishing boats and motor homes. For maximum service life each could use a dedicated amperage(S) in addition to voltage(S) charging and withdraw out regimen. Won’t matter 'cause you and I know for “Ruff and Ready Jury Rigged” you will be sourcing these all out used/abused/recovered as best as possible and/or cheapest on sale sourced.
Same with the alternator. It WILL be some kind of automotive free/used/cheapest sourced.
It’s all good. For inspiration look up DOW memeber here Tim Johnson member page Bio.
There he has a posted up YouTube of his home brewed system. 11 hp rated Honda spinning a 60 amp car alternator into hand series and parallel connected 4 to 6 set of 12 volt batteries.

On the HomePower article do note pictured back then they were using an older exernally voltage regulated mechanically “point” style Chrysler auto alternator - single “field” terminal. Later external regulated Chrysler alternator would have had a different back “button diode” rectifier shape and TWO “field” terminals.
Here is a save you hours and hours and me or someone else thousands of words tip: Chrysler/Dodge/Plymouth (and 1988 later bought Jeeps) obstinately, Very wisely stayed with extenally regulated alternators - get the voltage regulator control OFF the shaking, hot engine. GET THESE as a strong preference. Chrysler or Bosch or Nippon Denso production doesn’t matter off of any of thier vehicles. GM dropped out of externals in 70-71. Ford in 80-84. I CAN externally regulate convert a-n-y-t-h-i-n-g. I will no longer waste 10,000 typed words explaining this one unit at a time, for one person at a time, for the hundered or so different internally regulated unit variation you could stumble across. ONE mistake. One of three internal screws - two insulated sleeved and one not in a Delco 10,12,15,17 SI swapped wrong and out comes all of the majic smoke. Sizzle!Poof! In an Instant! Almost all other internal regulated units are much harder to convert. Easy to convert truck units much more difficult to find free and expensive to buy - hundreds $'s USD.
North America and at least 90% of the world auto units all take 17mm internal bore pulleys. The early Chysler production nut-less “pressed on pulley” alts Do need some $30-$100 tooling to handle pulley and front bearing service. Any mech/Tech doing power steeing pumps will have the removal tools. Need a 6" vice or small press to reinstall the “pressed-on” pulley. Chysler nutted untues the same as everyone else’s.
90% North America and 50% of the world truck alternators will have a true 7/8" internal bore diameter pulleys with the rest a crap-shoot of different true metrics, and inch and metric tapered dimensioned needing pulleys. Free here is only pulley cheap on some. Careful.

You should NOW have talked and read enough to know that that you really DO want to have full control at least over the voltage charging levels.
NO PERMANT MAGNET woo-woo ( sell you a $80. USD converted unit for put into my pocket a cool $100 USD in easy profit) unit will give you direct field strength control !! DO NOT BE A woo-woo Sucker. One of these could have acquired you more/better batteries or a really nice inverter.
Save all of the Internet searchable and encourged “efficiency” chasing for some other worthy endevor like flat row plant the beans?, hill the beans?, raised bed the beans?, where for you and your situation it will make a difference. Back in my third story walk up before married days this was easy as a balcony pot planting decision.

Steve Unruh

Poor soil around here, raised bed for sure; concentrate my nutrients to a small area, less to water in the dry part of summer (not your problem I guess… :slight_smile:

Gentlefolks, I haven’t been following this thread but in 2007 I uploaded a short video of Wayne’s alternator. Back then he had a 12 volt system with his windmills and storage batteries etc etc etc … At any rate, here’s the link
There may be a youtube link as well but I can’t do that with the phone modem. I think he e-mailed the video to me direct and I shrunk it down for us po folk.
He still has the parts from it and I checked them out last visit. He would switch the spark plug wire manually from the gasoline to woodgas setting. That would knock me on my ars. I think he used a pinto distributor and battery and coil for the gasoline and had re-keyed the flywheel for woodgas. Maybe he will catch this post and pipe in …
Mike L

Here it is on Youtube:

HI Guys
I appreiciate the patience one must have when describing something to people that are new to not just gasifiers but the bigger picture of how gassifiers and power sources “fit” into ones needs.
I can only imagine how you must feel when reading posts from people like me - thinking out loud in possibly the wrong direction - your keystrokes are appreiciated.
Can’t really knock the woo-woo sites too hard, even if you don’t give a hill beans, if it wasn’t for those searches I would have never found gasification or this site.
I figure for every twenty altenative energy internet sites I’ve researched I get at least one that’s worth the informative effort :slight_smile:
I read every post usually twice on this forum.
This is the only forum I’ve ever felt comfortable posting on.


Everyone here is talking up Dutch John’s Micro Gasifier PDF. I have searched the site using all the keywords I can think of. Where might said PDF be found?

Also, Admin ChrisKY, this is not necessarily a bug, but the word “gasifier” always shows up with a red squiggly under it as a misspelled word. Is there a dictionary you can add certain keywords to? Seems annoying that our pride and joy shows up as a mistake needing correcting . . .

Hi Alex,

The Micro gasifier is on DJ’s site http://woodgas.nl/microgasifiers/microgasifiers.html. No PDF that I know of.

I don’t have any control over your browsers spell check. But you can usually add a word to your dictionary. Right click it with the squiggly line, and one of your menu choices should be “add to dictionary”. YMMV with different browsers etc.

Here’s an off-the-wall theoretical question… What would happen if I were to hook up a vaccuum cleaner motor to a small engine? I have 2 broken vaccums with working motors that seem fairly heavy duty. One is rated at 16 Amps and the other at 12 amps @115v draw when in use. That’s 1840 and 1380 watts, respectively. Could one turn those motors with an engine and get power back out at near those ranges? What kind of power would I get?

I wish that guy with the “12 running but damaged lawn mowers for 150$” on Craigslist hadn’t sold them out from under me.

Hey BrianH
You got to be loving this next 24 hours of finally sunny good weather, eh? I’ll be doing lots of gasoline powered mowing today. I now have two walk behind mowers set up to do this now this year with ~1 quart (~one liter) gasoline per half acre of the ~5-8 acres total I now do versus the different rider mowers used at a min 2-3 US gallons an acre each and every time.
So on your lawnmower hunt look and pay ONLY for the B&S/HONDA/KOHLERS and Chinese clones engines with OVERHEAD VALVES as identified by a stamped steel bubble topped valve covers on the cylinder end cover to get these kinds of power converion efficiencies. The ONLY ones in my opinion now with even bothering to woodgas fuel convert.
Pass right on by any with finned flat cylinder heads with the spark plugs in the middle. Was $30 for my wife to gift to me a used front wheel power drive machine with the good 190cc OHV Briggs&Stratton engine. And I got for elder womand mowing excange a nice 22" ball bearing high wheel mower to put my wife’s good Honda engine onto. A “free” running flathead, fuel hog B&S engine came along. Oh well. Here - I’ll throw it your direction - catch!

On your generating with brush type vacumn cleaner motors. Depends a bunch on the way the motors are internally wired up.
But no matter - even the best possible motors to generate with are all brush positioned and windings sized/slot timed biased to be much better motors than generators. And generators internally designed biased to be much better generators than motor over as motors.
So even IF it works only expect at best 20-30% of the genrated OUTPUT versus the motor power INPUT. Most of the rest of the internal energy will be bucking inefficiencies converted into unit killling heat.
On the also many different different types of no brushes AC motors there IS one type able to do efficient over motor rated RPM power spun generating. Not in your needs range though as these are big heavy min 5 hp three phase motors.

Steve Unruh

Wow Steve, you mow 5 to 8 acres several times a year? Why not plant the area with trees or is that against the local codes to have a forest on your property? If you have charcoal, I would not be hard to convert your push mower to run on charcoal gas and forget about the gasoline. If you have lots of charcoal, you could even convert your riding mowers and smile with every acre mowed. Lets see, that is SWEAM. OK, I’ll lay off for a little while. As a forester, I love to see open areas returned to forest. I built my house 30 years ago in a field. Now there are so many trees around it there is not enough sunlight for a garden.
On a real serious note, thanks for the information and knowledge you freely share on this forum. There are a lot of good nuggets and I know you spend quite a bit of time relaying them to this audience.
Got to shut down my batch of good old eastern hardwood charcoal now,
Gary in PA

Ha! Ha! Hi GaryG. I knew if I ever said how much that I mowed and put up pictures someone would call me out on this!
Well only ~1 acre inside the two houses, three dog, fenced yards is by actual choice.
About three more acres once was cow chawed down untill my good in-the-Town progressive neighbors decided no more livestock grazing inside the Town limits 10-11 years ago. Then have been having to mow for different Town, County Stae Departments “fire hazard” “nuisance” " noxious weeds" ordinances. Then for our own insurance liability expenses we’ve been working back the forest/trees from adjoining nighbors building falling possibilities. Sigh. And that put me back into “noxious weed” problems.
Actually this all being driven by the “gotta grow more houses” builder/beaver/investor/spectulators. My county is one of the west coast 2% per annum growth area magnets within 2 hours of an International airport and they cannot conceive anymore here sustainable ways rebuilding Urban in-place thinking.

Anyhow the game is to drive old Stevie out. They suceeded with three other Town edge families. The cow fields and forest edges are all 30% rock fields - this was never tillable land. I’ve busted up two push mowers and three different riders in the last ten years keeping it legal. I do not think I could keep any bolted/welded on systems intact to be dry summer fire safe. I can barely walk after 2 hours sitting mowing from the pitching around. Plus when I was seen switched to riders “they” thought I was weakening and that they were winning and that made me have to spend out in a couple of legal challenges. So back to push mowing and even picking up 1/2 and 2 1/2 also in-Town acres of other older niegbors mowing obligations just to show that a healthy grow- it/eat-it Rural will always be able to out sweat the pizza and cake eaters, video gamers of the world. Happy now that I’ve got the gasoline for a full once over down to the equivelent to ONE trip into to the big City and back = 3 US gallons = $12. USD. (and also three beers coolant/energy drink for the mower operator)

Brian back onto topic here are some of my in-use aquired/bought overhead valve engines so you can see what to look for.
You will find that GaryG and I generally only put up what we actually are, and have been using as personally commited proofs of concepts. Brothers in Life Philosophies.

Wet Rainforest Softwoods - No-Can-Make-Visible-Smoke - Steve Unruh