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recharge a battery while in use

recharge a battery while in use

recharge a battery while in use

(OP)
Good morning everyone,
  I have an idea but not sure how to start. We use 36VDC forklifts here at our facility. In attempts to reduce the amount of time it takes to change a battery and get more run time out of the battery is it possiable to design a charger to run off the batteries power but put a charge back in the battery while it is in use. I had thought of some sort of generator but not sure where to go from here, We use 36V 1250amp/hr batteries. If this is a goofy idea please be kind.

thank you for your time
2570

RE: recharge a battery while in use

Unless you are breaking the laws of thermodynamics, which it is generally accepted to be quite difficult to do, your charger running from the battery can't produce more than it consumes. So if it was totally lossless, the energy going back into the battery would be exactly equal to the energy being taken out by the charger. A lossless charger hasn't been invented yet, so the energy going back in will always be less than being taken out of the battery, and thus your battery will slowly discharge, not recharge.

If you do manage to make this work, you will be a very rich man!

----------------------------------
  Sometimes I only open my mouth to swap feet...

RE: recharge a battery while in use

Scotty, we HAVE to be missing some key element here, like the forklift stays within 20' of the charging station, the charger is a portable gas unit quickly fitted/unfitted, etc.  Otherwise, this question holds no more use than any other perpetual motion machine idea...

Dan - Owner
http://www.Hi-TecDesigns.com

RE: recharge a battery while in use

Electric motors tend to be 80 percent efficient or better. If you want to make the battery last longer you need to go after the inefficient stuff



Use the law of conservation of energy.


Rather than friction brakes you use reactive brakes.

The spinning magnetic field acts like a generator and takes that energy and puts it back into the battery.

RE: recharge a battery while in use

(OP)
Beentheir,
  are you refer to regentitive braking? If not please exsplain reactive brakes.

 2571

RE: recharge a battery while in use

Yes, he's talking about regenerative.

2571, If you're asking about a way to charge the battery without getting energy from someplace else (a gas-powered engine, a cord to the wall, etc.), please let this thread die now and save us all a lot of time.  What you're asking for is not physically possible.

Dan - Owner
http://www.Hi-TecDesigns.com

RE: recharge a battery while in use

How else do you conserve energy?

You reduce your loses by conserving.

RE: recharge a battery while in use

(OP)
macgyvers2000,
  What does this mean,
 Everyone has had a great idea at one time or another in their life, but most are forgotten, never given a chance to materialize. After many frustrating years of writing those ideas down but having no outlet to see them realized, a change was inevitable. Products began to appear, but their form was rough... no cohesive force was behind them other than an intense interest to design and build. Found this on  the web at a sight that appeared to be a well organized company. That I'm sure does hinge on the impossiables.  

2571

P.S. Giving up is not an option.
  

RE: recharge a battery while in use

2571,

Those "other" products you mention, rough form or not, made it to fruition because they were physically possible.  What you're asking for defies the laws of physics/thermodynamics and therefore is not possible in any shape or form.  This isn't a matter of "It's been too expensive in the past" or "Someone just hasn't found the right way yet", it's just not physically possible, no matter the amount of money or thought you put into it.

Dan - Owner
http://www.Hi-TecDesigns.com

RE: recharge a battery while in use

2571,
your only option appears to be a small add-on petrol or diesel-powered generator fitted to each forklift which runs continuously to charge the battery during low battery drain periods (makes a sort of hybrid powered forklift). Even this could prove difficult to get right if you are trying to avoid an overnight charge on the batteries; to specify the generator correctly you would need to have an idea of the time available for recharging (i.e. duty cycle of typical forklift running time versus stationary times) (remember, ampere-hours in x charging inefficiency = ampere-hours out)

Otherwise the only way to keep the batteries topped up is to return the forklifts to a charging station between jobs.

RE: recharge a battery while in use

BrianG is correct for portable as long as you are in an open enviornment. Stinky motor and carbon monoxide in a close space are not exceptable. Know your application.

I also believe (maybe wrong) that electric power is far less expensive than fossil fuels.

An interesting point you mention is replacing the battery. I can only quess that this occurs when the battery dies. You have an AC/DC converter already mounted on the fork lift, correct?

RE: recharge a battery while in use

2571,

While I don't agree with how some of my fellow members have phrased their responses, at the core they are correct in their statements.  Energy in = Energy out.  There is no getting around that.

RE: recharge a battery while in use

melone might also have said

energy in = (useful energy out + losses)

Everything in the real world has losses.

----------------------------------
  Sometimes I only open my mouth to swap feet...

RE: recharge a battery while in use

Thermodynamics 101:
 You can't win.
 You can't break even.
 You can't quit.

RE: recharge a battery while in use

VE

That belongs on a poster in my cube.

It can be applied to most problems.

thanks

RE: recharge a battery while in use

It was a goofy idea and in the main, they were kind with Melone being the kindest.

rmw

RE: recharge a battery while in use

Coincidence or not, someone (think government agency) is going to try using Hybred material movers (think forklifts ect.) at the loading docks of long Beach and San pedro, CA. Just to find out if theres any savings there, then they want to investigate airport towabouts and other vehicles.
Sounds to me someone JUST heard the word hybred and wants it to fit everywhere.

 
 

Best regards
pennpoint

RE: recharge a battery while in use

Hybrid can work very well for something that needs a decent amount of power in short bursts and very little power between those bursts.  Run a small engine that can produce something in excess of the average power required and run it at a constant load, storing the power in batteries.  Then use the batteries to supply the occasional loads.

RE: recharge a battery while in use

That link to Steorn sounds a bit freaky.  efficiency coefficient in excess of 100%!!

You would think that if they had indeed created this technology they wouldn't have this much trouble getting it externally verified though.

RE: recharge a battery while in use

Yes, that link certainly is wierd. it has echoes of the room temperature cold fusion saga a few years ago. Took a while for someone to discover the flaw in the maths and shoot it down. Conservation of Energy Rules OK!

RE: recharge a battery while in use

What we used in one factory where I worked was a bridge crane that ran on rails that were mounted on the floor. This was used to change the battery of 48 volt forklift trucks. You generally need 3 batteries per truck. When lifting the battery the 2 lifting cables need to pass through the ends of a spacer bar so that the 2 cable lift straight up and do not distort the case of the battery.

This also provided time for cleaning the battery tops. If the battery top is dirty there will be excess standby discharge leading to short battery life and the charger will be unable to fully charge the battery. First, disconnect battery from forklift and charger. Second, rinse top of battery with water hose and nozzle. Then use hot water mixed with sodium carbonate a.k.a. washing soda, sodium bicarbonate a.k.a. baking soda, and then with liquid dishwashing detergent works just as well as factory made sprays. Then, let mixture do its jobs, scrub the battery top a little, then rinse with hose and nozzle. Just be sure to be gentle enough with the hose and chemical mixture so as not to force it into the battery caps.

Some smaller forklift trucks have passive conveyor rollers underneath the battery and you pull up to the charging station, roll ou the old battery, push the truck about a foot, and roll in the new battery. Some charging stations use conveyor balls instead of rollers so that you can move rhte batteries in 2 directions thus saving on having to push the forklift or pallet jack with muscle power.

At one time Vienna, Austria extended their steetcar system using battery buses that towed a trailer with batteries in it. There were peiodic stations where a bus would drop off a drained battery trailer and pick up a new one. This also saved on the problem that trackless trolley buses have no equipment ground.

At one time the New York Central railroad had tripower switching locomotive for local train movement over street tracks in some parts of Nwe York City. These had 600 volt traction motors that could run off of 3 power sources:

1. The underrunning 660 volt 3rd rail of nonstreet right of ways. This did not recharge the battery as you need 700 to 750 volts to recharge a 600 volt lead acid battery.

2. A 600 volt lead acid battery - this was handy for confined areas that did not have a 3rd rail. This also worked for sidings that were too costly to electrify not to mention that a 3rd rail on customer property needed a local disconnect switch to prevent power theft and safety problems. The conductor or brakeman could forget to lock off the disconnect and interlocking the disconnect with the track switch would have been a nightmare. A third rail in say a scrapyard would be one hell of a problem even if of the inwsulated underrunning variety.

3. A 750 volt DC diesel generator that was used to recharge the batteries and power the traction motors when running on open streets where a 3rd rail is impractical.

The battery also helped with the matter that early diesel locomotives did not have a whole lot of power available from the engine.

Mike Cole

RE: recharge a battery while in use

I forgot to mention to always use safety goggles when cleaning a battery - there can be some amount of sufuric acid thrown into the air when hosing and washing it. Rubber gloves also help a lot but because there is a large hole for your arm sulfuric acid can get into the inside of the glove. Back in high school chemistry class we were instructed to frequently wash our hands and the INSIDE of the rubber or latex gloves.

Also save some of the sodium carbonate soduim bicarbonate detergent solution for washing hands and shoes. A small amount of sulfuric acid can take an hour to eat your skin or shoes and makes for a very nasty surprise.

Also wash hans BEFORE using the restroom. spreading sulfuric acid to your naughty bits really hurts.

RE: recharge a battery while in use

I think I have used bicarb to clean about 10 auto batteries.. I don't think a single one lasted more than a week after being cleaned!  I haven't ever figured out if it was the bicarb poisoning a cell/s or if in every case the battery was having problems and that was why I was cleaning them in the first place. Wish I knew.

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

RE: recharge a battery while in use

Quote:

Also wash hans BEFORE using the restroom. spreading sulfuric acid to your naughty bits really hurts.
Oooooh, got a cringe on that one...

Dan - Owner
http://www.Hi-TecDesigns.com

RE: recharge a battery while in use

itsmoked
Just for my clearification. Just how did you clean those 10 batteries? Inside & out? or just the outside?

Best regards
pennpoint

RE: recharge a battery while in use

Ha!  No,  just the safety glasses a tooth brush and a box of baking soda.  Smear  the baking soda around dribble some water on watch it foam, scrub.  Add more BS, scrub, lightly rinse, repeat until foaming stops or I get bored to tears.  Always careful to not run any into the cell hole (in any obvious way).

Then within about two weeks I'm down at the store buying a new one.  But since I have two diesels I'm actually down buying (2) everytime.. evil

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

RE: recharge a battery while in use

itsmoked; Thanks! I'm relieved, one can read into these post too much.
 

Best regards
pennpoint

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