Scissors lift batteries

[LarryFine]

a single 24v charger is not advisable if you want to have good batt maintenance & life.

That was the original setup with four 6v batteries.

 

[Galt]

We took 2 chargers and left all wiring in place. charged 2 with one charger and 2 with the other. thanks for all the replies I really enjoy this stuff. Lights are done.

 

[kwired]

That was the original setup with four 6v batteries.

And is pretty typical for this kind of equipment as well.

 

[FionaZuppa]

That was the original setup with four 6v batteries.

an engineering barf. what else is there to say.
individual batts do not degrade the same. charging them should be done on individual basis. for a piece of equip, the user should expect one cord to plug in.

perhaps for the ill life of a set of 6v's in a scissor lift, using a 24v charger suffices until one or more of the batts decide to take a dump, and the charger will have no clue.

its not that hard to engineer in a 4x 6v charger

 

[kwired]

an engineering barf. what else is there to say.
individual batts do not degrade the same. charging them should be done on individual basis. for a piece of equip, the user should expect one cord to plug in.

perhaps for the ill life of a set of 6v's in a scissor lift, using a 24v charger suffices until one or more of the batts decide to take a dump, and the charger will have no clue.

its not that hard to engineer in a 4x 6v charger

Couldn't you say the same thing but applied to the single cell level?

 

[GoldDigger]

an engineering barf. what else is there to say.
individual batts do not degrade the same. charging them should be done on individual basis. for a piece of equip, the user should expect one cord to plug in.

With all due respect, which is not much in this case, series strings of Flooded Lead Acid (FLA) batteries have been in use since FLA was invented. The ability of FLA to gracefully withstand a controlled rate overcharge allows a single charger to fully charge all batteries in the string, with a short period at the end of charge letting the higher State Of Charge (SOC) batteries gas while the lower SOC batteries (or cells) finish charging.
Given that the batteries are purchased and replaced as a set and are discharged only in series means that a single charger works fine.

Other battery types such as NiMH or Lithium chemistry do not have the same overcharge tolerance, which is one reason for adding a Battery Management System (BMS) to the system. There is still just one charging current source.

 

[LarryFine]

Couldn't you say the same thing but applied to the single cell level?

I was about to say the same thing, that a given battery is three, six, or more cells in series.

 

[GoldDigger]

I was about to say the same thing, that a given battery is three, six, or more cells in series.

Except, of course, for 2V batteries, which are actually used in some large applications to allow a single series string instead of series parallel combinations.
And, also, of course, the four cell 8V batteries. :angel:

 

[FionaZuppa]

Couldn't you say the same thing but applied to the single cell level?

not really. a batt only comes with a + and - terminal to attach to. if a cell in that batt goes south the smart charger can recognize it. a series of 20 batts and one cell goes south, a smart charger might say "sumtin aint right" but now you need to go test every batt individually.

@GoldDigger - the respect is mutual. i guess.
does the scissor lift really use FLA batts ?? that would be shocking (no pun intended, hah)

 

[GoldDigger]

not really. a batt only comes with a + and - terminal to attach to. if a cell in that batt goes south the smart charger can recognize it. a series of 20 batts and one cell goes south, a smart charger might say "sumtin aint right" but now you need to go test every batt individually.

@GoldDigger - the respect is mutual. i guess.
does the scissor lift really use FLA batts ?? that would be shocking (no pun intended, hah)

i don't know about typical scissor lifts, but typical fork lifts definitely use heavy duty FLA battery packs. FLA still gives the best combination of energy density, charging speed, and cost, especially where weight is not a consideration. And for both fork lifts and scissor lifts a heavy battery bank actually allows the designer to get better mechanical stability in use.

 

[FionaZuppa]

my guess, unless the pics show otherwise, fork or scissor lifts are not using FLA batts.

 

[FionaZuppa]

my guess, unless the pics show otherwise, fork or scissor lifts are not using FLA batts.

i guess FLA's are still used (thats crazy). the ones i have seen in new machines are sealed AGM's.

 

[gadfly56]

i guess FLA's are still used (thats crazy). the ones i have seen in new machines are sealed AGM's.

At my last shop we used lifts all the time but we rented. I would guess that 90%+ of the time there was an issue with the batteries it was due to low electrolyte (I realize the OP's issue was the charger). I started telling my techs to bring a gallon of distilled water with them. You still might need to add some ions, but at least you could get the batteries to charge up somewhat.

 

[GoldDigger]

At my last shop we used lifts all the time but we rented. I would guess that 90%+ of the time there was an issue with the batteries it was due to low electrolyte (I realize the OP's issue was the charger). I started telling my techs to bring a gallon of distilled water with them. You still might need to add some ions, but at least you could get the batteries to charge up somewhat.

:thumbsup:

Once the electrolyte level gets below the tops of the plates you start to see permanent damage, as well as higher internal resistance. Unless there has been an electrolyte spill or violent boil off, you should never have to add acid to the battery.

Sealed (AGM) batteries have a lower internal resistance for faster/more efficient charge and discharge, and are far easier to handle. But they cost more for the same amount of energy and do not last as long (either in cycles or in calendar years.)
AGMs can also be permanently damaged by use of a charger set to the normal charging voltage for FLA batteries, so some diligence is required. Other than that, they are indeed low maintenance.

 

[Galt]

What causes sulfateing of the plates and how do some chargers clean it off or at least they claim to.

 

[GoldDigger]

What causes sulfateing of the plates and how do some chargers clean it off or at least they claim to.

In a normal discharge process lead on one plate is converted to lead sulfate, converting one sulfuric acid molecule to a water molecule and moving the sulfate group over to the lead plate. This lead sulfate is "fluffy" and the reaction can easily be reversed by applying a reverse (charging voltage.)

But the longer the lead sulfate stays in place the more it converts to a "hard" crystalline form which requires a higher reverse voltage to break down and does not conduct as much charging current.
In a standard FLA battery sulfation can develop within days, especially if the charge level is below 50%.

Some chargers claim to break up the sulfate crystals by applying a much higher charging voltage through periodic pulses or a high frequency AC waveform superimposed on the DC. Just applying a higher DC voltage electrolyzes the water in the electrolyte to hydrogen and oxygen gas at unacceptable levels ("boiling" the battery), and heating the battery in the process.
There are deep and bitter religious arguments about whether de-sulfators actually work and what really happens at the molecular level.

 

[Galt]

So is it advisable to charge often,noon and breaks and try to stay above 50 percent.

 

[gadfly56]

So is it advisable to charge often,noon and breaks and try to stay above 50 percent.

GoldDigger said "days" not "hours". I would assume that as long as it goes on charge overnight you should be fine.

 

[drcampbell]

The shallower the depth of discharge, the longer a lead-acid battery will last.
Definitely plug in the charger during lunch hour and breaks.

 

[GoldDigger]

GoldDigger said "days" not "hours". I would assume that as long as it goes on charge overnight you should be fine.

As far as sulfation goes, ON should indeed be fine. But for general battery health it is probably best to minimize the maximum depth of charge, so any substantial recharge like lunch or long shift changes might still be a good idea. Tossing in a 15 minute charge during the day probably does not help and may actually hurt. Opinions differ on that.