Help me size an alt and battery bank to 4hp petteroid

[panaceabeachbum]

I purchased the nice little Kissan 4hp Petteroid from another member here a few months ago.  I have run the engine a bit and I am very happy with it and finaly ready to build a small generating system around the engine .

I have decided on using an automotive type alternator to charge a bank of batteries and an invertor for my 110v needs .  What alternator would work well with this small out put engine? 

 

[Doug]

Old style externaly grounded and externaly regulated Chrysler 60 amp from the 70s.

Spin the alternator around 2500 rpm and it should be very reliable and easy on things.

The reason I say the externaly regulated and grounded units is they are a little easier to adapt. Your going to want to add switch to isolate shut of the field for starting and You can add some external reostats to the stock regulator to get you a measure of control over charge rate ( Amps )

I would even go as far to say find an old mechanical regulator from a generator and use that in conjuction with a reostat. You would be amazed how easy to is to adjust such a system and easy it is the service and understand it if there is a break down

[panaceabeachbum]

what are the downsides of the inexpensive internaly regulated alternators used on GM and other chevy vehicles?  Only asking on this one as I have two vehicles that use the GM alt

[SteveU.]

Hi Guys
You are only going to be able to drive a 60 amp alternator maximum with your limited hp.
Down sides of the Delco SI? The external fan hurts and can draw blood. Has to be driven at a higher RPM for a given output due to the smaller diameter rotor/stator and a single pull through fan air circulation versus a double fan double doughnut air circulation. Internally regulated IT will decide everything assuming you have a single battery of the type it was manufactured for. You cannot over ride its preset limits so you will never be able to explore the different charging rates and voltage settings you really DO need to learn if you are ever going to maximize a multiple battery bank life and usability.

But on the other hand Doug, those Chyslers have the difficult to change pressed on pulleys. Best decide the right pulley at purchase.

Regards
SteveU.

[mobile_bob]

how many volts is the battery bank to be?

bob g

[mobile_bob]

allow me to expand my question a bit

1. how serious of a system is this to be?

2. is this something that will likely grow over time?

3. is efficiency a concern to you? if so how big of a concern?

4. is this project a low budget affair? if so how low?

5. is this a medium budget? basically how much do you wanna spend?

6. do you plan on useing expensive batteries? and what type, gell? agm? flooded? dilithium crystal?

7. do you want to babysit the charging process? or do you want an automated controller to properly control the charging?

8. is this a standby unit, or one that will be used either full time or with some regularity?

9. are you locked into 12 volts? can you go with 24 or 48?

a hundred dollars worth of stuff and a couple hours connecting it all up might be sufficient for you needs, but
likely will not be the most efficient and will require a lot of babysitting to properly charge your batteries,

for maybe 500 bucks and some careful shopping, and modification of a used alternator, step up to 24 or 48volts
you could get a much more efficient system (burn a bunch less fuel) 

for maybe a grand, you can get a proper controller which will allow for 3 stage charging and temp compensation
along with 24 or 48 volts and have a very efficient system, (burn even less fuel)

it is just very difficult to charge at 12v nominal and get any efficiency, you will have to settle with ~50% on average
moving up to 24 or 48 will get you ~80% efficiency which is a gain of some 60% in efficiency over the 12volt base unit.

that gain in efficiency represents a significant amount of fuel.

bob g

[panaceabeachbum]

I am wide open to suggestions.

I have a budget of around $1500 , already have the engine. Pulleys are not an issue as I can machine just about anything imaginable for the drive system.

24 or 48v is just fine , I do not want to babysit , I would like to be able to crank the engine when needed and not be concerned with watching the system, boiling batteries etc .

I dont plan on using it daily but do want to explore the possibilty that it could be pressed into service daily , Its very possible I would use it daily for the duration of the winter , about 3 months here were I am , but in reality it will be a hobby/ excersise in daily power generation for home use.  I have a supply of used motor oil that exceeds 200 gallons per month

Open to suggestion on batteries, the upside of auto/semi truck batteries for me is I have an in and can get batts at an extremly low cost with a very liberal exchange policy if one dies so even though they are less efficient thats probably the route I will go . My main limitations are sticking with the 4hp engine I have

[panaceabeachbum]

also need reccomendation on inverter, I wanted to use one of the used xantrax (spelling?) units avail cheap but I believe they are 12v input

[Doug]

Pulley issue:

Do you have the stub shaft flange for that engine?

It uses the same stub as your cam for starting. There are two version the long and short one I have spare long if you dont and want to swap.

If not you driving on the flywheel or you may condiser having buying this part.

There is also a specific flat belt pully again desgned to bolt directly tot he petteroid flywheel if you want to go that way. I have one of those too but next question is do you have a 15 3/4 inch flywheel......

Don't try and drive more than 10% rated power through your Petteroid 1/2 PTO ( cam drive ) if you have the iron gear. The steel gear is rated full power but is special order.
I doubt Pat has any of these parts or any parts for them but he can probably get them of you drop him a line.

[jzeeff]

You might look into a Bosch high efficiency long haul alternator.


http://www.bosch.us/content/language1/html/715_5978.htm

[panaceabeachbum]

Doug I do not have any out put shaft as of yet, there are three bolt holes on the machined face of the flywheel. i was planning on just machining a one piece pulley that will match the alt and bolt directly on the flywheel, assuming the face of the flywheel runs true. I will check the flywheel with a dial indicator and if not I can true it up on the lathe.

I had decided against driving off the camshaft. 

[Doug]

Send me a PM with your email adress and I will fire off some pictures of the parts I have here if you would like to see them.

Another thing to consider might be an old Automotive generator. If you slow the engine down further say 1200 rpm they run a little smoother and quieter and a 30 Amp delco gen would probably also serve as a good starter for the Petteroid as well.

[mobile_bob]

first things first

your not going to want to use truck batteries, they are just not made for deep cycling
you are also not going to want to use marine deep cycle, they too are not up to the type of repetitive
cycling you will be doing.

look into true deep cycle batteries, the entry level are golf cart batteries such as the t105 trojan

and the upper end of flooded cells are the rolls/surrette batteries

there are other technologies, such as agm, and gell, each taking specific charge regime

flooded cells would be the direction i would recommend because of their rugged nature, hard to kill them
by charging at too high a voltage a time or two, some technologies are quite unforegiving and can be damaged
if charged improperly.

the bosch unit is a nice one, but will only reach the 70% efficiency at ~80amps, and go way down as the amperage
goes up,, of course they don't tell you that.

likely you will need to do some testing, but my bet is the engine is going to return its best economy at near peak load
or around 4hp, so you are going to want to work it there, that works out to about 3kwatt mechanical

i would target for 2kwatts electrical as a max to start with. thats 66.66%efficiency alternator and drive system.

now the trick is picking the alternator, matching the drive, and putting it all together.

your going to want to study up on batteries, charge controllers like balmar, xantrex etc, voltage's and inverters a bit
to start with so you can get the best result for your money.

ymmv
bob g

[panaceabeachbum]

I had pretty much read the same on Batts on a couple of solar sights, I was just in hopes the large semi batts might be suitable as i can get them very cheap , same source also has large QTY of golf cart batts, just have to ask about pricing on those .  I also have a possible source on some big commercial batteries the cable company uses to power their system when the power is out . Any links to similar builds or info that might jump start my project?

[mobile_bob]

they would be suitable as storage if you only needed about 5% of their capacity, or if you used them as a buffer
between the altenator and the inverter, where the only time you would draw power from the inverter was while the engine
was running.

if you have either in mind, then yes a truck battery would work just fine and give you good service.

the problem is most folks will expect to run much longer on batteries and deplete them much deeper than 5%
and in some case down to much more than 50% where the thin plates of a starting battery start to wear awaw very quickly.

ever notice when a car battery that is drained dead never really comes back to what it was before, it might once or twice, but
generally if it happens more than a half dozen times you are looking for a new battery.

i had a customer that ran a fleet a P series step vans, they would park at delivery drops with the 4ways on for up to 30 min at a time
sometimes 6times a day,, those batteries were doing good to make a year and never two years, i could get two years by installing the
highest capacity battery i could buy,, but never more than two years.

liftgate trucks are another problem, if the driver is not allowed to run the engine while useing the liftgate, like in an underground garage
the batteries are good for about 1 year,

in both cases the batteries are used hard, and then recharged very quickly,, but
the damage is done, a bit at a time.

it is said an automotive battery is good for maybe 50 deep cycles before it is junk,, i think 50 is optimistic
however we know that the battery is good at starting an engine, up to several times a day, and do so for at least
4 if not 5-7 years... these starts are likely less than 5% of the batteries capacity.

as for recommendations of info on engine driven battery chargers, the net is full of them...

and just as everything else, there is a bunch of crappy info, and tons of systems centered around a reostat
none of which i would recommend because quite frankly they are not doing it right, yes it will work, but
far from optimized in my opinion.

the one thing i can tell you to stay away from is any pm modified delco alternator as a battery charger, yes they
will work, but the hype surrounding them is just that... hype designed to part you with your money.



bob g