Using Listeroid/alternator combo as a battery charger

[matteas]

Newbie here trying to figure out the most cost efficient way to charge batteries for an off-grid home. Electric usage will be around 200-300 amp/hr day maybe less. I'm leaning toward a battery bank of around 1000amp/hr.
I have read with allot of interest in the leece neville/balmar combination of charging batteries. Seems like bang for the buck might be the most efficient use of the listeroid as a battery charger.  I'm looking for more info on who has this setup (or something similar) and what you like/dislike about it. I'm mechanically inclined (or would like to think so, used to be a mechanic) not as proficient in electronics. All info is appreciated.

[mike90045]

If you have a great beefy charger, fine. 
Just 2 problems,

1) the batteries will take a good stiff charge till they are about 75% capacity, then charge tapers off, then it's time to get the washer machine going, etc.....

2) losses in the battery charging sequence, you loose about 20% recharging a flooded cell battery, AGM is less loss.


Go for a 48V system, less copper loss in the wires, because you aren't pulling as many amps, for the same wattage.

[Tom]

Do you have inverters? If so use the charger in them with the 240VAC output of an ST type generator. That way if the inverters fry you can still power your home. That is the way I'm planning my system.

[matteas]

I don't have an inverter yet but it's part of the plan.  Now, what if both an st head is used in combination with the alternator setup.  One on each flywheel but not used simultaneously. Maybe the best of both worlds? The alternator would charge batteries and the st head power larger loads. 

[cujet]

Wouldn't the ideal setup be a syncronous inverter/charger that will work with or without an AC generator?

Chris

[xyzer]

matteas,
I have a 12V Leece Nevelle 165amp alternator I am going to hang on my 6/1 also. I will be watching this thread to see where you end up. I'm headed in the same direction and am also lacking in the power storing and conversion area. From what I have read up on so far I kinda wish (I think) I had a 24V alternator. I'll be watching and see where this thread goes!
Dave

[matteas]

Dave- what size battery bank do you have?

[Doug]

Dave it may be as easy to make your alternator a 24 VDC unit as trip to the local repair shop and have them change the guts out or trade it in for a new one.

There are lots of units like this where I work. I know we send out crates of them and they strip and repair them. The just replace the guts and make up rebuilts as needed.....

I've also been thinking if one were to make an MG set from a DC motor and induction motor you could provide suplimental power from the battery bank by belt driving the induction motor to generate when you have a power demand peak. This wouldn't be efficient but for starting a heavy motor load or a short durration peak load.

What you would need to do is find a large induction motor and capacitor bank, and a DC motor ( 24 vdc larger than fractional motors are scarce but exist ) and wire some controls. The controls would detect peak, drop your alternator and pick up the MG set. When the MG set comes up to speed a contactor ( and some cussioning resistors in series with a second shorting then closes and brings in the peak power ).

This one is a high speed series motor and that complicates things you want a shunt or better yet PM motor...

http://cgi.ebay.com/2-HP-12-24V-DC-ELECTRIC-VEHICLE-MOTOR_W0QQitemZ330154329568QQihZ014QQcategoryZ26226QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Here's another option but now you need to 48 volt suply and way to charge it ( possibly with induction motor and switching power suply but thats complicated again )

http://cgi.ebay.com/ebaymotors/Briggs-Stratton-Etek-DC-Electric-Motor-New-in-BOX_W0QQcmdZViewItemQQcategoryZ46093QQihZ015QQitemZ250153070752QQrdZ1QQsspagenameZWDVW

I'd only look hard at something like this in some cases where I know I only need about 3000 watts most of the time but wanted to build in some very heavy surge potential. I would be inclined to go witht he Etek motor if I had a 48 volt inverter system already but it couldn't provide this kind of peak.

I would not expect this to be any more efficient that 40 %.

Thats my very out of the box thinking and a very old think way of doing stuff.

[ronmar]

Well in my opinion, diversity is the key to happiness in an off-grid power application.  Sun dosn't always shine, wind dosn't always blow, water dosn't always flow. parts of a system don't always keep working.  As mentioned, the diesel will be great for the bulk charge, but way underused(bad for the engine) for the final charge.  Here is where some lower potential supply such as solar would come in handy when conditions permit.  I think being able to shift a belt and put a traditional AC generator online is an excellent idea.  Good for when a battery or inverter decides to crap out unexpectedly or to add load to the engine after a bulk charge by taking house load off inverter and placing it on the generator while you finish off the charge.  A 3 phase induction motor with output rectified and feeding a switching DC-DC power supply might be an interesting and fairly economical way of making DC for charging also. 

If I was doing this(and I might be when I build my new house:)) I would look at primary solar with the slow speed diesel as a backup/makeup.  IF the sun has good availability where you are at, it would probably require the least operator intervention/attention.  I mean I like messing with this stuff, but I don't think I want to HAVE to mess with it 3-4 times EVERY day just to keep the lights on.  For efficiency I would go with 48V also.  For a 200-300AH useage, a 1000AH bank sounds good to not pull them below 50% with a day or two of use.  Ideally I would plan for enough supply/storage capability to not regularly need the generator, only during unusually cloudy weather or for performing an equalization/overcharge maintenance to clean off the plates.  Of course idealism costs money, lots and lots of money...   

Ron

[mike90045]

Well in my opinion, diversity is the key to happiness in an off-grid power application.  Sun dosn't always shine, wind dosn't always blow, water dosn't always flow. parts of a system don't always keep working.  As mentioned, the diesel will be great for the bulk charge, but way underused(bad for the engine) for the final charge.

This is exactly my plan, have enough solar PV to run in normal conditions, keeping the listeroid and a 5KW ST as backup/bulk charger.  I plan on needing to fire it up at least 1x a week, AM,  in winter to bulk charge (short days & rain= less solar charging) and run the washer, dryer, vacuum, and such in the AM, and as load drops off, shut down the genset, and let the PV top off the batteries.   Some of the newer inverters will sync and run parallel with a genset. (not the same as grid-tie, which if you have too light of load, will overvoltage your local grid)

I've also understood, from this site, that an ordinary car alternator, is a horrid load, you don't get much output from it, and they can't sustain heavy loads (  http://www.balmar.net/index.htm   excepted ) with their wimpy automotive rated fans.

[Tom]

Hey Mike, that is exactly my plan too. Looking for the electrician to do the solar system now!

[matteas]

My location is upstate NY near Ithaca. Solar during the winter is tough. Need a big solar array! Wind is probably more consistent and when the $$$ allow may be the way to go. 
Right now it's a matter of $$$.
I'm figuring a listeroid project if set up correctly would be about half the cost of decent solar or wind power. It would be more time consuming and need of constant tinkering. But it would provide some relatively quiet power at a decent price and if run on WVO or bio-diesel not to stinky to boot. 
And yes a hybrid system would be a dream.

[rcavictim]

Hey Mike, that is exactly my plan too. Looking for the electrician to do the solar system now!

To hook up to the solar system properly you will also have to hire orbital mechanics.

[xyzer]

matteas,
I am in the process of getting my feet wet in the solar area. I bought the Leece Nevelle for all the reasons mentioned plus it has a better duty cycle. I was to have a 12V system on the generator for a fan if needed and was thinking go big and use it for other things if I got a Balmar regulator. Well as I looked into inverters it became apparent 24V would be a bit more efficient. I haven't mounted it yet and need to learn a bit about solar and battery banks. The technology in this area is really moving fast and I'm slow! It is easier to get 12V out of the 24V than 24V out of a 12V system. Like I said I'm going to watch this tread and learn from the guys already knowledgeable in this area. I can always trade or alter the alternator like Doug said. That was the cheap part!
Dave

[rmchambers]

Dave,
   I have a 24 V inverter setup with two banks of batteries on it which at the moment is a monster UPS for my home computer/networking gear but eventually will feed a "critical circuit" panel when I've got all my ducks in a row.

The 24V system does let you pack more punch for your system but you can also garner an insanely huge number of amps if something goes wrong - I've got 150amp dc breakers for each string and then a switch that allows 1, 2 both or off to switch which battery string is online (so I can take one offline for maintenance etc).

My issue is that the inverter I have doesn't lend itself to netmetering so my long term plan is to either replace that inverter with one that does, or get enough stuff together such that I can generate what I need while charging the batteries and pull myself off the grid for a while here and there.  Realistically I can't go completely off-grid but having a reliable alternate solution for the power outages is something I really want.  (wife says I don't need it, but there's a difference between want and need).

RC