Electrical Fork Lift Battery

First, depending on the output of the charger, you may need to charge it longer the first few times.Checking the specific gravity is the best way to judge the charge state of the battery.

What kind of performance were you expecting?

Are all of the cells topped off with electrolyte?

Are you sure the forklift is not defective in some way such as a short which may be reducing the battery's performance?

Have you tried charging the battery for more than 7 hours?

When we replaced our fork lift battery, the accompanying data sheet indicated to set the charger to the overnight position (12 hours) for the initial charge.

How long was the fork lift operated and under what type of conditions and loads before you noted lack of expected performance after the 7 hour charge?

Ya need one of these...

http://www.amazon.com/Equus-3320-Auto-Ranging-Digital-Multimeter/dp/B000EVYGZA

and one of these...

Hydrometer

I expect that people who come here asking us for answers will actually listen to us. When we ask for a clarification like "What kind of performance were you expecting?" or "what does your fork lift manufacturer say about initial charging times?" I expect that those who respect our opinions enough to ask us in the first place, will respond when we ask what we hope is a critical question.

My clarifying questions are these:

1. Did you mean 450 amp hours is the capacity of your battery or that the output impedance of the battery is 0.05333 ohms? (24V/450A)
2. How many amperes of current is the rating of your charger?
3. Is this a charger built into the forklift or an external charger?
4. Was this battery a replacement to an old forklift or is everything new here?

What is the current output on the name plate of the charger?

What type vehicle is the battery in? Make and Model.

Also note that the problem all along may have been the charger not the battery you replaced. Was the charger tested before replacing the battery?

If the battery was bought new then it's possible there is a flaw. Tack welds internal of one of the cells could be bad. One way to tell is a load test. With battery under load check the voltage drop across each cell. Should be pretty even usually with in a tenth of a volt.

Hydrometer sometimes will not indicate a problem especially on a newer battery. Under charge conditions the current may not be enough to produce heat to cause a bad connection to open up. So after a charge reading on a hydrometer may indicate the battery is good.

Under load a lot of time you don't even need to take voltage reading the bad cell will bubble profusely.

I think he just want to do a load test.

first , thank you all for responding to me , i hope my English is good enough , the charger as well as the fork lift has no name plates ( of course because both are used ) except for the old battery which had a label mentioning that the battery is a 600 amps capacity , but regardless of my Recommendations the supplier who's a local forklift and generator spare parts dealer in Amman (Jordan) replaced the old battery with another one( replacement to an old forklift ) of 450 amps capacity claiming that it will do good , i know that sounds ridiculous but it worked with our main forklift which is originally a 800 amps capacity battery caterpillar , the caterpillar is working up until now equipped with a 550 amps battery from about one year ago .

so far my procedures were as follows:

1- though i have been told that the forklift is ready to work i told the driver not to but it on the charger (which is built out), i asked him to push it to the limit so the battery energy gets drained and the charging indicator would light red ,and it didn't take long.

2- i placed my dc clamp meter on one lead and started the charger , i measured the dc amperes flow , it was about 96 amps , it started to decrease slowly and gradually , i checked it every hour for about 7 hours , by the fifth hour the ampere steadied at 30 amps and it refused to go lower.

afterwards the driver proceeded with his regular work , but the forklift wasn't in good condition and it didn't last long before it was totally exhausted

Well it sounds like your charger circuitry is sized properly for an over night recharge of 10 to sixteen hours. All I can suggest is the standard collection of troubleshooting techniques. Look for current leakage paths across the battery terminals. A common energy stealer is damp salts on the battery case making an electrolysis path. Look also for no current being drawn from the battery when the fork lift is idle.

Good luck.

Most electromotive equipment the battery is sized to last 6 hrs ran full out for the duration. Most are not put to use like that so they make it through a 8 hr shift. The charger is also designed to recharge the battery in 6 hrs. Your reduction in Ah rating will reduce the time the equipment can operate with out charge. The fact that it's used will also reduce the available AH rating. Years of use the battery sulfates and the plates crumble away. This could be your poor performance as the reduction in size and lost of plate surface area will not produce amperage needed for the equipment to preform up to expectation.

The battery AH rating is stamped into one of the jumper between cells.

Does the charger have equalizing setting? May help in removing some of the sulfates from the plates and returning it to solution as acid improving surface area and increasing available acid for increased duration.

Did you do a really good job cleaning the cable clamps that go to the battery. It's very inexpensive, might help and can't hurt. Make certain they are very tight once they are clean.

actually , the battery had been well set up and restored by the supplier , all I'm worried about is the fact that the replacement battery is 450 amps while the original one was 600 amps ,which make me wonder would that reduction in value affect the over all performance

I would think that would matter. It's all about the amps when it comes to length of useful working time. Although it sounds like its not gettiing a full charge to begin with.

Is that amps or amperehours you are quoting?

i meant the capacity of the battery expressed in amperes , you see , my fears are about the potential negative affects that could happen , what should i expect

"i meant the capacity of the battery expressed in amperes , you see , my fears are about the potential negative affects that could happen , what should i expect"

The problem with what you are saying here is that battery capacity is typically measured in ampere-hours (Ah).

If it is actually the maximum discharge current of the battery that you are concerned about, then you need to determine how much current the motor draws in normal operation. Provided the motor draw is less than the maximum discharge current of the barttery, there will not be a problem.

thank you so much

To add to the above : the figures that you gave above for battery capacity - 800 originally, then 600 and now 450, these do seem about the right size numbers for an electric forklift, in ampere-hours (Ah).

If this is in fact the case, then your forklift is now capable of working for a little more than half of the time that it did when new before needing to recharge. If this is a problem then you need a larger-capacity battery.

we have two forklifts , the first had a battery of 800 ah that was replaced with a 550 ah battery , the one we are discussing about ,was originally 600 ah battery that got replaced with a 450 ah battery .

i asked the forklifts driver today about the forklifts working duration , he told me that it shows signs of weakness in about 2 hours of continuous work unlike the way it used to be , any way how can i get the best of it since there is no come back as i learned from my manager , another thing , our charger is capable of recharging the battery in 7 hours , i recharged it until i saw bubbles coming out , wouldn't that be enough to remove any sulfate forms

Watching for bubbles is not the way to determine state of charge.

Batteries gas during the charge cycle. Is normal. Appearance of bubbles does not indicate that charging is complete. It's probably just getting started.

Are you determining your charger's capability on its historical performance or the observed gassing?

Have you tried a longer charge interval as previously suggested yet?

i decided that 7 hours are enough , by watching the ampere meter readings as i mentioned in earlier comment , but i wanted to say that the battery was producing gas as if it were boiling , and i wanted to know what effect it would have on the sulfate forms

This "boiling", as you describe it, sounds a little aggressive.

Have you measured the electrolyte SG of the battery (it is one battery right?) in its discharged and "charged" states yet?

What are the the loaded and unloaded battery voltages measured at these same conditions?

What is the charger output voltage at start and end charge? (and in between)

its 12 batteries connected together , as for the procedures you advised me to take , i will do it exactly and let you know , i really appreciate a lot your concern as well as the others , such discussions adds to my experience a lot .