How do you know if it is the battery or the charger?

We have this battery powered floor scrubber machine where I work. It is has 2 large 12 volt batteries up pos.---------> neg., to stay 12 volts. The other day it smelled like rotten eggs in the room, and I found that the batteries had the water cooked out of all the cells equally well. Lifting the machine's lid out of the way exposed bubbles coming out of the cells, and the enclosed area (now opened) was quite warm. 12 cells in all. I used 5/6 gallon distilled water to refill them. Then plugged in charger.

The next day, I smelled the sulfer smell again, only not AS bad. Liffted the lid again. Water levels down SOME (1/4-3/8ths inch maybe. Not dry cells like the last time). Added water. Voltmeter right after that said about 12.4 volts. I was expecting less actually, but that is what she read. Then I plugged in the charger. The charger, included in the machine, has a nice big digital printout of the amps, and above that are 3 pictures of a battery in 3 stagers of charge: The left picture shows battery almost empty, middle being halfway charged, and right one shows fully charged. A red indicator light is over each picture.

Well, after plugging in the charger, the digital kept climbing to about about 12.5 amps (amps, not volts). But then within about 15 minutes it came down to 9.1 amps. The indicator light on the charger remained at the left red indicator light showing low battery. Then I did a voltmeter check during as it charged at the 9.1 recorded amps, and was nto coming down any more, and I got 14.4 volts. Note that below the digital printout is a large number 5 printed on the charger, and I'm wondering if that means you can expect a good battery, when fully charged, to come down to 5 amps?

Then I unplugged the charger and it read 13.06 volts.

So what do yo think is going on? Do you think the batteries acts like they have a hole in it?, and keeps taking a charge?, to where it can never drop the amps towards 0 or 5?, and stays at 9.1 amps? Or do you think the charger is malfunctioning, and keeps on charging, when it really should be going over to the right indicator light and shutting itself down, and isn't?

I am actually not the one who works on this machine. I intervened after talking to the janitor who runs it and adds water to the batteries when needed. Tonight when I called him up, he said he used to only have to add water to the batteries maybe once every 6 months. And he ALSO told me that he ususally would hear the charger's fan-motor run at first, but then later after it charged, he would no longer hear it (an indicator to me that the charger was shutting off to protect the batteries from over cooking.) Where instead,*I* caught the charger that 2nd day still running with the fan going.

Batteries?, or charger? Place your bets here.

 

I'm betting you don't have a battery hydrometer. Right?


the fluid level in a deep cycle batt will fluctuate as it discharges and charges. You should never fully fill a battery when it is discharged. Add just enough water to cover the plates, then charge, then check water level.

A battery will give off hydrogen sulfide (the rotten egg smell you smelled) anytime it is charging.

a battery at 13.06 volts is nearfully charged. at 2.2 volts per cell, 13.2 volts is fully charged.

Sorry I can't tell you what current output you should see. It has been too many years to remember everything.

It is hard to tell which unit is the problem without more investigation. Either a bad battery or a bad charger could cause the battery to boil out. If they had boiled out pretty equally, I would tend to suspect the charger though.

 

Hi Nap. At least you are around and not out for fish.

Never filled cells to top. Left it so the slots, that are like 1/2 inch vertical, are not covered, for venting.

I did have a battery hydrometer, that you mention it. Hmmm. Where IS that sucker? I have tools and supplies laying all over.

Yes - the cells were equally low, and equally in each battery as well.

So you are inclinded to believe the charger is perhaps stuck in the fully charging mode, and not shutting down?

 

I would think that first. Usually if one cell is bad (most batteries do not have all the cells go bad at the same time) that cell will tend to boil first although it does not neccessarily happen that way.

The fact that all the cells were boiled tends to show that all the cells were made to boil rather than boiling because of a bad cell.

a hydrometer would be good right about now.

as to fill; it sounds like they are a bit overfilled now as they are not fully charged but they are fully filled. As they charge, the water will rise. It should never be fully filled (where ou have it. above that is overfilled) until/unless it is fully charged. Doesn;t sound too bad though. Hopefully it won;t overflow.

 

would just pull the batterys and have them tested if two batterys are hooked in series one cable running from pos of one battery to neg of the other it is hooked up for 24 volts if they are hooked up in parrallel pos to pos it remains 12 volts would suspect atleast one battery is bad and causing the charger to not automaticly detect its nearing full charge and reducing amperage and basicly overcharging both batteries.

 

ecman`; what's a rough dimension of the batteries?

 

Sure about that? I am getting 12.5-14.5 volts from each battery while they are still hooked up together, no matter which battery I test. Nothing on the diagram where they even show the pos.--->neg. hookups to indicate a changeover to 24 volts. Also, both batteries cooked out fluid equally, so I would not be inclined to think one battery would be stone cold dead while the other is good, to = 12 volts.

 

I'll go out there soon to check on the overnight volts now that charger has been off all night (didn't trust letting it run). Remember I said that when I shut it off I had 13.06 volts? I'll measure them in a bit.

Also I expressed concern to one of the building's owners that I do not like the fact this machine is in the dual furnace/water heater/store room, with these gases. Furnaces and water heaters come with stickers telling you to not have various chemical products in vicinity of furnace, as this can break down key components.

 

greater problem than that:

the gasses emmitted contain a high concentration of hydrogen, which in case you were absent that day in high school chem, is flammable, or even explosive in proper hydrogen/oxygen ratios.

I was curious of the dimensions simply because bejay suggested pulling the batteries and having them checked. I don;t know what make/model the floor scrubber is but I have worked with industrial batteries before and can be quite large. One of the bigger ones I remember was about 4 feet tall, about 3-3/1/2 feet long and about 1 1/2/ foot wide. They weigh a ton (nearly litterally). Just wondering if taking them out for service was even a possibility.

simply no idea to the size from what you have posted to date.

 

The batteries are standard large car battery size of 12 x 6 1/2 x 8 deep. The one cover on each battery says "Deep Cycle".

I just came back from there.

Unplugged charger (was not plugged in all night) volts at 12.4, no matter if on my 20 or 200 DCV range. The 2 batteries are in a plastic container impervious to acid to contain spilled acid water. The batteries are oriented parallel in length so that one is pos.-----> neg., and the one next to it is neg.------> pos. At the left ends the positive and negative is jumpered together, with no other wires. On the right power end, there is no jumper. Instead there is a power cord where the sheathing is stirpped off and the one wire goes to the one battery's pos. and the other wire goes to the neg. of the other bat. And same goes for the two wires from the charger. Hence each post has 2 wires on it, each, on the right side battery terminals.

No matter how I test those batteries, I can't make my meter read 24 volts. I tried every combination, including diagonals. Pos.--->neg. at each battery is 12+ volts. And diagonals are 12+ volts. But across the two batteries where the posts are close to each other, and one is pos. and the other neg., I get no volts.

But here is what is odd: That charger is a Nilfisk Advance. Mod. #CBSW1 24V 13A 1U1a wet/gel, with a switch to shift from one to the other. What is THAT? So. Being that "u" (says so right on the charger's 'legend') stands for volts, and "A" for amps, you can figure out the numbers.

Now when you plug the machine in and look at the charger display, there are all kinds of readings that occur before it even lists at what stage of amp charge is required. First comes up the letters "SPEC". Then it says a couple other letters I can't recall.Then it says 24u. Then it says 25.5u. Then it shows 13.0A. Then it starts to sequence where the amps start climbing .1 amp at a time, starting around 8.0A, and keeps climbing till it gets to about 12.5A (not volts - that is just a coincidence). Then it stays at that setting for a bit and then .1 amp at a time, the numbers come down. Like I said yesterday, the number of amps does not want to come down lower than 9.1, (which does not seem right) and it shows the indicator light on "low battery" as it continues to charge.

I should have searched for my battery tester. Maybe it's out in my car in my toolbox of small testing equip., but I think that is my antifreeze tester I have out there. But I will check anyway and see. If I have it , when I go back out there later I'll test the cells.

.....................

On an unrelated note to this thread: I see other posts about people wondering if they have a bad battery or starter or alternator, yet it was only on my thread that I have been given the suggestion to use the battery cell tester to see if it is good. Frankly, something I had completely forgotten about. You get talking about volts and amps so much, that sometimes you forget other things.

Why no 24DCV reading, when the charger specs give 24 and 25.5u readout?

 

i appreciate your diligence and detail in analyzing this battery/charger issue...but floor cleaning equipment, deep cycle batteries and 24 volt systems are not within the realm of automotive service and repairs. so as not to chase your tail based on peoples opinions, why not try contacting the floor cleaner manufacturer directly and get the manual and/or some technical support from them. I, like you, would be concerned having smelled the hydrogen sulfide and observed batteries that were cooked dry and over heated...I'm just not sure this is the forum for this discussion.

 

I posted it here as they are standard car batteries, and I thought the theory would apply regarding cars, and those here who are mechanics would love to help. I thought the worst that would happen is thread would be transfered to equipment.

Tomorrow I AM going to see the company from where the machine was purchased, as we were never given a manual, and I need that for other things. But I did not know if they would know as well as some of you guys, what might be wrong, since this is something that bvery wel might happen between any person's car battery and some person's home battery charger, let's say. That is why.

Sorry if this has been a problem. I had no idea. Nor can figure out why.

 

Normally i don't thread over here but i am glad i caught this in the time and due i work as electrician and i have dealt alot of industrail charger from time to time


however try do the trobleshooting with the 24 volt charger it can get very tricky and there is not much leeway on them normally most industrail charger do have a timer to shut them off in 8 hours [ on standard charge rate] or electronic contoller it will shut off much sooner than that.

to order to read the battery voltage on 24 volts system they are little more tricky than standard 12 volts and if not proply hook up like both batteries in parallel and use the 24 volt charger for sure will smoke them up fast but if battery hook up in series with 24 volt charger it should be working properly

here a quick run down how it connected neg* [battery A or #1] postive <----> neg [battery B or #2 ] postive *

at the * star point it will read 24 volts and fully charged it expect to read about 27 to 30 volts depending on type of charger.


the other tibbit here that the charger is sized by battery size and recharge time peroid.

however if you supect that the charger putting out too much voltage or too long a charge my suggest is take that charger and take it one of the industrail forklift or industail battery dealership [ don't bother with automovite parts store with this one ] they have tools to verify the operation of charger

Merci,Marc

 

here is a site that shows parallel and series connections for 2 batteries.

parallel will result in same as battery voltage. Series will result in additive battery voltages.

http://www.nyc-arecs.org/Connecting_...d_Parallel.pdf

page 2 has both diagrams.

from your desription, I am not sure of the connections so I'll let you take a look and tell us how they are connected.

 

I think I will only post responses to all parties, truly interested, by PM now.

 

Due to the interest from several people here, thought I'd update:

Saw the dealer today. He says that that particular onboard charger has a history for problems. 3 year warrantee.

I did not have chance to get serial number with code, to confirm purchase date yet.

He thinks twofold problem: Charger went bad and would not stop charging. He said it is supposed to shut down in about 3-5 hours. It never shut off. Battery cooked the fluids out. He says you cannot have the fluids cook out like that without ruining the batteries.

Hmmm. I remember, back when, having to add water on regular intervals, to my battery, and it was okay. I said that I thought you could buy electolyte additive for that. But he said cooking out the battery, way below the top of the plates, pretty well ruins the battery.

I then went nearby and bought new mechanics grade battery cells tester. He said I really need to run the machine for maybe 15 minutes first to put an amp load on those batteries and THEN do the cell by cell testing. Tomorrow I will try to spend a little more time with this.

Just thought I'd update you all. Tomorrow I might know more.

 

he is correct. It removes what is termed a "surface charge" which is essentially an artificially high reading.

 

End of saga:

Battery cell tests all real low, except for 2 of the 12 cells into the fair range. Yet charger kept charging - and today it never even dipped below the max current of 13.0 amps. Remember I said the other day that it at least make it down to 9.1 amps?

Called farm and barn store and they had these batteries on sale for only $60 ea. after rebate plus return of old one!! (At a discount national chain store, I priced these batteries the other day at $110 ea.!) The automotive dept.man I talked to(they got a big garage at the farm and barn) knew of my application and said they sell many of the marine deep cycle batteries to many people who install them in series, in various machines. He said that whenever the battery cooks out the fluid and you smell that rotten egg smell, he said the batteries are toast, without question. The dealer guy said the same thing, yesterday.

Installed new ones. Now charger comes way down in amps the way it should. Farm and barn mechanic told me to not leave charger unattended for any real length of time, to rule out charger as cause of batteries being cooked. But he said that after all the use and recharge cycles that if someone did not add the distilled water when needed, that it could be JUST the batteries - and it turns out it was. We now all think the janitor just did not check the batteries often enough. Then the worse they got - the worse they got, quicker. The manual says to check the batteries after every recharge cycle! (Although, of course they are bound to say that.)

THE END

 

please do not park that machine in a room where there is open flame or sparks, I have seen 3 different automotive batteries blow up and it will scare the cr**p out of you. If you are in the room it could be deadly.
Remember Murphy was an optimist

 

One thing I feel real good about is the fact nothing DID explode the day it smelled terribly, in that room. There are 2 9-element elec. water heaters (cover plated over) and two furnaces with closed combustion (with fresh outside air serving the closed combustiuon chambers -luckily). The machines have been parked in that room, being charged daily, for 3 years, so at least this is nothing knew. I have told one of the main directors my concerns, but I have a hunch they will do nothing, as space is limited, and they probably think this is theory since nothing has ever happened..........know what I mean? But, at least MY conscience will be clear. I told them.