Battery banks for alt energy lighting

[Old Scool Bus]

I have 60 DJW12-1.2 (12 volt 1.2 AH)  maintenance free sealed lead acid batteries.

When I got them most were supposedly new unused some were used as battery power for GPS tracking devices from a buy here pay here lot.

They are all really low voltage and don't want to take a charge. Anything I can do to salvage these batteries.

My plan for usage is have 3 20 battery banks to run just my LED lighting. They will be charged by small windmills I have built out of various 12 volt DC fans. One fan will mount in my ticket window and run off of vacuum as I'm driving. 2 larger ones will be mounted in the other windows and charge the other banks as the wind blows through the window while driving. They also will have small solar panels to help with the charging.

I'm also building a wind mill out of a trolling motor for stationary use.

I'm hopeful this all works as well as I think it will

[Bestekustoms]

Do You Have Any Pictures Of Your Bus You Could Post On Here?
I Could Really Dig Seeing What Your Working On.

THANKS

JOHN

[Jeremy]

One fan will mount in my ticket window and run off of vacuum as I'm driving. 2 larger ones will be mounted in the other windows and charge the other banks as the wind blows through the window while driving.

An entirely false economy surely?

Jeremy

[John316]

 

John

[philiptompkjns]

Hey OSB, I'm just curious really... If you are driving why would you not use your alternator for power and to recharge any batteries?

[oldmansax]

OSB,

Have you already tried using any motors for generators? If so, do you have any data at all concerning output? I have a bunch of motors in the shop & have been thinking about putting up one or two (or 4 or 5) as stationary windmills. I also thought about mounting a fiberglass truck fan to an old alternator.

I would really be interested in anyone elses real world trials.

TOM

[Jeremy]

Tom

Just thought I would jump in on your question as this is something I've played around with. Firstly, alternators do not tend to make good generators in this application as of course you need to apply a field voltage to them before they can even begin to generate any power of their own. They are good at producing a a steady output at varying RPMs, but generally a permanent-magnet motor and a charge controller is a better solution.

Small, efficient, low-voltage DC motors such as those sold by hobby and model shops can be used as a basis for wind turbines - although the design of such motors is quite different to that of generators built for the job, which have the windings and magnets laid out in a completely different way. Stepper motors (from old tape decks etc) are a better approximation, and there is a particular type of motor occasionally used in washing machines which are highly sought-after by folks who enjoy building with turbines.

Then there is the 'bobble generator' design which is a different solution again, and far better at producing power at the sort of low average wind speeds which are typical in most localities. (And burning diesel to produce a slipstream to drive your turbine isn't the answer!)

It's the low (and turbulent) wind speed problem that eventually made me realise I was wasting my time trying to build a wind turbine. I did however buy a 24v DC traction motor from a mobility scooter (£20 on Ebay), and have built a very nice generator that is powered by my mountain bike! Reasonably hard pedaling, a power capacitor from a car stereo system and a cheap charge controller produces a strong and smooth 12v supply and keeps me fit!

Jeremy

[TomC]

Nothing is for free.  Using the wind pressure or vacuum while you're driving as a source of power for your wind generators will probably take more power to run (because of the wind resistance encountered compared to having a clean non interrupted surface when all windows are shut) then just simple using belt driven alternator(s).  And using so many small batteries is just going to be a maintenance nightmare trying to keep them all balanced.

I just had a conversation with Lifeline batteries yesterday, and they are making the 6v L16 size battery with 400 amp/hours.  I am going to want around 1000-1,500 amp/hours, and using 6 total of the L16 (3 pairs for 12v) will give me 1200 amp/hours. Granted they are around $500.00 each, but worth it for the size and lack of maintenance they require-plus I am mounting the batteries inside my basement (not a problem since AGM batteries don't out gas). Good Luck, TomC

[Sean]

I have 60 DJW12-1.2 (12 volt 1.2 AH)  maintenance free sealed lead acid batteries.
...
They are all really low voltage and don't want to take a charge. Anything I can do to salvage these batteries.

You need to be absolutely certain about the chemistry and electrolyte containment, but many batteries, particularly lead-acid, can be resuscitated by a controlled application of very high voltage and current.  In other cases, lead acid batteries can be recovered using a technique known as "pulse desulfation" and there are battery chargers with this capability as well as stand-alone desulfators.

...They will be charged by small windmills I have built out of various 12 volt DC fans. One fan will mount in my ticket window and run off of vacuum as I'm driving. 2 larger ones will be mounted in the other windows and charge the other banks as the wind blows through the window while driving.

OK, but you do know that any energy you derive from "wind" while you are driving comes from the dynamic energy of the bus, and therefore must first be generated by the main engine.  Imagine mounting a forward-facing wind turbine on the roof -- when you drive at, say, 60mph, there will be 60mph of apparent wind through the turbine, and it will generate power.  That amount of power, however, MUST be less than or equal to the extra engine power required to move the bus over what would be required without the wind turbine on the top.  It's that pesky First Law of Thermodynamics again -- you can't get something for nothing.

Generally speaking, driving with the windows open (or, for that matter, adding protuberances like wind turbines to the outside of the vehicle) will cost much, much more fuel than simply extracting the needed power from an existing engine-driven alternator.  So if you think these mini-turbines are going to be cost-effective, you're under a mistaken assumption -- charge the batteries with the alternator; that's what it's for.

Now, using wind turbines while parked is a whole other matter.  Any power you derive this way is truly "free" to you.  Lots of commercial turbines on the market in the 1-5 kW range, as well as plans for home-built.  The chief complaint most folks have with these is that they are quite noisy.

Solar panels, of course, work equally well whether traveling or parked, although better results on a parked coach can be achieved by tilting the panels to the south.

FWIW.

-Sean
http://OurOdyssey.BlogSpot.com

[gumpy]

Sean,

I've always been curious if the same would hold for wind turbines that are mounted behind the bus, and below the roof line such that they catch the air as it curls over the back of the bus. Would something like this still take away from the efficiency of the engine driving the bus? 

I'm not thinking of doing that, but just curious. I understand that adding a turbine directly in the air flow would require more power, but can't seem to rationalize what would happen if the turbine were mounted in the vortex off the back of the bus. It seems like the air might curl around and put the turbine towards the bus, possibly adding power to the bus. Any chance this is even remotely possible? 

craig

[Sean]

... Any chance this is even remotely possible?

Well, yes actually.  Without violating the First Law, it is important to remember that many of our most complex machines are very, very inefficient.  So the best way to get "free" energy is to take something that is very inefficient, and make it more efficient.  For example, our diesel engines are very inefficient, giving off much of the energy input (in the form of diesel fuel) as waste heat.  If you can use that heat, for example to heat your domestic hot water, it is "free" for the taking.

Likewise, any vehicle moving down the road is wasting a lot of energy as air turbulence behind it.  All sorts of shapes can improve the aerodynamics of a vehicle, reducing this waste and making the vehicle more efficient.  Buses and trucks, however, are notoriously bad in this regard.

So, yes, it is possible (but not likely) that putting a turbine in the turbulence at the back of the bus might actually improve, rather than reduce, the aerodynamic efficiency of the entire system.  In other words, it is possible that, rather than requiring more fuel input to move down the road, such a turbine might make use of dynamic energy, in the form of the air turbulence, that is otherwise simply wasted.

It is important to note, however, that it is equally likely that such a turbine would actually make matters worse, possibly much worse than one, say, mounted on the roof.  Rear-end airflow is a black art (as opposed to front-end airflow, which we can model pretty well with computers), and most vehicles that have aerodynamically engineered rear shapes are perfected in wind tunnels.  The same would apply here: you'd have to build it, try it, and see what happens.

While the side-window turbines the OP proposes might seem to fall under the same rubric, it is pretty much a given that vehicle dynamic energy suffers considerably when the windows are open vs. closed -- in other words, even more of the input energy is wasted as turbulence.  The mini-turbines might take advantage of the turbulence, so perhaps if you were going to drive with the windows open anyway for, say, cooling purposes, they might (but probably won't) be efficient.  But closing the windows and pulling the power from the alternator is the lower-waste choice.

-Sean
http://OurOdyssey.BlogSpot.com

[Old Scool Bus]

Hey OSB, I'm just curious really... If you are driving why would you not use your alternator for power and to recharge any batteries?

Because of the complexity of batteries I did a lot of research both on here and asking "people in the know" These batteries should only be charged with 1 or 2 amps because of their specs and the size of the terminals. That eliminates using a charging system on a bus. (for all practical purposes)  Secondly it is just another fun, cool, interesting project.
I'm learning as I go about something I know very little or nothing about.

OSB,

Have you already tried using any motors for generators? If so, do you have any data at all concerning output? I have a bunch of motors in the shop & have been thinking about putting up one or two (or 4 or 5) as stationary windmills. I also thought about mounting a fiberglass truck fan to an old alternator.

I would really be interested in anyone elses real world trials.

TOM

I have done some redneck testing in my lab (bus)  but I travel alone so writing down data is usually not easy or safe.  The small fan I hooked to my multi meter and held in the ticket window @ 60 - 65 mph with the vacuum it created I got 13.5 volts @ if I remember right 10 amps. By altering the angle I can vary the volts. I will put in a charge controller.

The bigger fans were tested on the back of my motorcycle with varying results. The trolling motor being the most defying.

I have 60 DJW12-1.2 (12 volt 1.2 AH)  maintenance free sealed lead acid batteries.
...
They are all really low voltage and don't want to take a charge. Anything I can do to salvage these batteries.

You need to be absolutely certain about the chemistry and electrolyte containment, but many batteries, particularly lead-acid, can be resuscitated by a controlled application of very high voltage and current.  In other cases, lead acid batteries can be recovered using a technique known as "pulse desulfation" and there are battery chargers with this capability as well as stand-alone desulfators.

Thanks


[/quote]OK, but you do know that any energy you derive from "wind" while you are driving comes from the dynamic energy of the bus, and therefore must first be generated by the main engine.  Imagine mounting a forward-facing wind turbine on the roof -- when you drive at, say, 60mph, there will be 60mph of apparent wind through the turbine, and it will generate power.  That amount of power, however, MUST be less than or equal to the extra engine power required to move the bus over what would be required without the wind turbine on the top.  It's that pesky First Law of Thermodynamics again -- you can't get something for nothing.[/quote]

I doubt that these little fans running off of vacuum will affect anything.

[/quote]Generally speaking, driving with the windows open (or, for that matter, adding protuberances like wind turbines to the outside of the vehicle) will cost much, much more fuel than simply extracting the needed power from an existing engine-driven alternator.  So if you think these mini-turbines are going to be cost-effective, you're under a mistaken assumption -- charge the batteries with the alternator; that's what it's for.[/quote]

I don't use an ac so they are usually open anyhow in warm dry weather.

[/quote]Now, using wind turbines while parked is a whole other matter.  Any power you derive this way is truly "free" to you.  Lots of commercial turbines on the market in the 1-5 kW range, as well as plans for home-built.  The chief complaint most folks have with these is that they are quite noisy.

Solar panels, of course, work equally well whether traveling or parked, although better results on a parked coach can be achieved by tilting the panels to the south.

FWIW.

-Sean
http://OurOdyssey.BlogSpot.com

[/quote]

By the way these are very nice and useful replies, thanks

[Sean]

...
These batteries should only be charged with 1 or 2 amps because of their specs and the size of the terminals. That eliminates using a charging system on a bus. (for all practical purposes) ...

Umm, probably not.

Remember, just because an alternator is capable of producing, say, 100 amps, that's not how much current will flow into a battery.

If you consider the alternator an "unlimited current" source (a theoretical construct, but close enough to reality for this discussion), then the amount of current that will flow to the batteries when charging is dependent on only two factors (given a specific battery construction and chemistry):

1.  The voltage (not current) produced by the alternator.  This is set by the regulator.
2.  The state of charge of the batteries.

If you set your regulator for a maximum charge voltage of, say, 14 volts, and you've arranged these batteries into a 12-volt string, it's unlikely that they will draw more than an amp or two if they are above about 50% DoD (based on the size you indicated).

This is one of those cases where you just need to experiment.  Connect a discharged 12-volt string of batteries to a regulated power supply with an ammeter in series, then crank the voltage up to 14 while watching the meter.

Note that this is all irrespective of whatever other batteries are connected to the alternator; if those batteries are more fully charged, the regulator will actually call for less, rather than more, voltage.  So the only important factor is the upper limit voltage set on the regulator.

Of course, in this type of parallel arrangement, you will want to insert an appropriately rated diode between the alternator/main bank and this set of small auxilliary batteries -- you don't want power going the other way!

-Sean
http://OurOdyssey.BlogSpot.com

[loosenut]

There are two ways to approach the issue.  One, which seems to be the main interest of the thread, design a fan set up that would lower the bus's air friction ala the way truckers do with a cab boob. 

If lowering the air friction is economically possible, considering the number of high profile vehicles in the US it would provide a nice payday.  I would guess that it is not easy to engineer. 

Two, is the Toyota way of using wasted energy on the braking cycle.  I would envision engaging the turbine instead of the jake.  The Prius charges while going downhill and braking.  It would be cheap to engineer.  It would only take attaching a variety of sized generators to the bus and not the amount of drag.

From a tinkerer point of view being free of the grid-er-generator and sticking it to the man is mildly interesting.  However, from a money point of view it is like lighting 50 cent cigar with a hundred dollar bill.  In April I loaded up on propane for my generator and stove.  I've put many more hours on the generator than the bus and I've yet to burn through a $100.00 of propane.   

During the same time I've burned through close to $900.00 diesel.  Saving $900.00 would be riveting.

Supposedly UPS is testing a hydraulic assist.  During braking, pressure is applied to a hydraulic 'spring' that uncoils to accelerate the vehicle.  If it works that would be something to waste some time on.

Mike

[Old Scool Bus]

The trolling motor is kicking my a$$ but I refuse to tap out or cry uncle just yet.

My next trip to the salvage yard I'm getting 4 pieces of aluminum to make blades out of. I'll cut them to shape then have them bent in a brake press to achieve the best angle (compound) or twist to catch wind.  Think I'll go 48" maybe 36" to have a 6 or 8 foot rotor. Then try 3 and 4 blade arraignments to see which works best.