I have just purchased a used set of EXWFF11 Exide batteries that have a 2 year replacement warranty. They were at a good price and if I can a get couple good years out of them I will be happy.
However the best the supplier can give me for charger settings is these below. I have tried the manufacturer's website and they just have the same PDF.
Taper charging single step charger at 2.1VPC Taper 2:1 AMPS 96.9, Taper 1.7:1 AMPS 87.2.
Taper charging single step charger at 2.5 VPC AMPS 58.1.
Equalising Rate AMPS 23.3.
Constant Current Charging Rate AMPS 45.5.
This is a 48V 775AH FLA battery, I have 2 Classic 150 chargers with 8KW of solar panels in total. Has anybody had experience with these type of batteries and what settings I should use?
Best I can work out is the 2.5VPC will be 60V @ 58.1A However I regularly get 100A charge with my current set of batteries before they reach absorb voltage of 59.2. Are all Flooded Lead Acid batteries the same as far as voltage times go? The old set are Trojans that have reached the end of their usable life.
You should call manufacturer for exact charging specs - they should be able to tell you .
But they are probably in same ball park as the East Penn Deka cells if you need something to go by before you get the other details.
Take a look at this chart - the flooded 2v cells section
http://www.eastpennmanufacturing.com/wp-content/uploads/Renewable-Energy-Charging-Parameters-1913.pdf
Also try another exide dealer that services those batteries - they should be able to tell you what to set absorb and bulk for.
If Exide has specific gravity readings charge and watch the SG to see what voltage and current it gets to when SG is 100% charged. Make note of current - you can use that as your ending amps . It should level off when it gets to 100% SG readings.
And Vic will recommend that you number each cell - and keep a book to log SG readings in so you can tell what the starting SG is and if it changes over time.
Larry
Thanks Larry,
I will try the manufacturer, so far I am getting no sense out of the people in Australia, seems the manufacturer is based in India.
oh - okay . My battery supplier out here sells the East Penn Deka forklift batteries and services them too. He gave me a tour of his place and it was impressive. They will take back used fork lift batteries and load test each cell, and if some of them are bad or weak , they have other cells with similar age and load tests that they replace them with so they can keep the battery going lot longer. He said the ones in the center of the pack are often the ones that go bad - because those are the ones that get hotter and that is the enemy of battery longevity . They have real large load testers that can handle large amount of amps over long period of time.
That is why I suggested a dealer because if they are like our dealer he knows his stuff about batteries ! Been doing it a long time too.
Larry
I have bought them from the Australian distributor who advertised them as being suitable for solar use. But they don't know how to charge them other than using forklift chargers.
I plan to take them out of their container they have a cable that bolts into the top of the cells to connect them rather than the old style lead links. There is some slack in the cable so I will be able to space them apart a little to get better cooling. I need to take them apart anyway to unload and place them in their new home.
You should take voltage readings and SG readings of each cell and record. That will tell you if you have any cells that are low , and you can see how it reacts when you do equalizing charges if needed.
Those batteries if taken care of from beginning ( no sulfated cells ) and if you don't discharge them more than 20 % to 30 % should give good service for 10 to 15 years or more.
Let us know how it goes !
Larry
Quote from: BioPower on November 18, 2017, 11:17:42 PM
I have bought them from the Australian distributor who advertised them as being suitable for solar use. But they don't know how to charge them other than using forklift chargers.
I plan to take them out of their container they have a cable that bolts into the top of the cells to connect them rather than the old style lead links. There is some slack in the cable so I will be able to space them apart a little to get better cooling. I need to take them apart anyway to unload and place them in their new home.
If those are deep (tall) 2V cells you want to keep them in their case after removing them to relocate because of weight of all cells in case. Without the case the tall plastic cells will begin to deform and will cause major issues. The metal case is what supports these tall cells. They do not need to be separated for better cooling. You'll do more damage to the cell by removing them from the metal case than any temperature will cause. Besides the Classic has temp compensation using the BTS.
I had wondered if that would be an issue, the temperature is something I need to deal with though as we often get well above 30 degrees and where I have the batteries at present gets a few degrees warmer than that. I have air conditioning there but it does not cool it properly.
Even with temperature compensation (which I do use), higher temperatures reduce battery life.
Quote from: BioPower on November 19, 2017, 01:15:16 AM
I had wondered if that would be an issue, the temperature is something I need to deal with though as we often get well above 30 degrees and where I have the batteries at present gets a few degrees warmer than that. I have air conditioning there but it does not cool it properly.
Even with temperature compensation (which I do use), higher temperatures reduce battery life.
30 C is warm but not that hot. We can see 110 F on hot days and my prior set lasted 14 years with only one cell being a problem. Maybe piping the A/C directly at the cells.
But the case issue can warp the inside plates which is a bigger problem.
Consider that in a forklift these batteries get all kinds of abuse that would not be happening in home use . Yes I would put them back in the case too after you relocate them. Also consider getting some hydro caps or water miser caps to cut down on how much you have to water them .
Larry
Larry,
From the photo looks like he has a watering system to fill the cells. These work great and fill to the correct level.
I tried the yellow water miser caps before I put my watering system on and didn't really think they made much difference IMHO.
Yes the watering system is included, they tell me water from the tap is fine but I already have my own water distiller so I will keep using that. It operates when there is power to spare from the solar panels.
The more I read about these type of batteries the more I realize how tough they have to be. Regularly drawn to 20% SOC or less and charged up again every day. Plus not always getting the water topped up etc they have to cope with a lot. I would have to go 3 days with very cloudy weather to get down to 50%, I would not let them go past that, normally would be around 15% discharge each day.
Yeah that watering system would be good.
The caps I have had on my batteries of the past did seem to help but they also eventually get clogged up . Although later I read where it said to flip them open during equalizing - oops never did that ! No problems now cause I have some gel batteries - nice to not have to mess around with watering them but keeping fingers crossed they live up to their rated life time !
Seems like golden rule is never ever ever put anything but distilled water in a battery . That battery dealer either doesn't know much or has some very pure water !
Look up one of the charts for lead acid batteries sometime for depth of discharge vs how many cycles you get .
The only other thing that I have heard about having a huge oversized battery like you have and don't cycle it deep is is that the electrolyte can stratify so you need to take it down deep every so often and get it charging so that the electrolyte mixes up . I think it might be like once a month - not sure but there is someone I can ask. Thing is you need to be able to pour a lot of amps in to do that . I don't think you mentioned how many amps your system is . Use a generator if you have one and need to use it to help get those batteries bubbling good after the deep cycles.
I think Bob also mentioned in past that it may be good practice to just do extended Absorb time every ten days or so to keep stratification away . So when I had my lead acid I set up the Equalize for every 10 days with long Absorb time - if I needed real equalization then I would just change the settings as needed to accomplish that .
Larry
I don't believe the battery is oversize, every recommendation I have seen for FLA says don't discharge more than 20% most times. A typical daily cycle here will draw these down to 15-18%, with days of heavy cloud I would let it get to 50%. Any more than that and I will be starting a generator. At those drawdowns, I should get maximum life from them according to the charts I have seen, keeping the temperature down is another factor, if they are at 35 degrees it halves the life compared to 25 degrees. Soon I will be moving to a new property where I will be able to have a 500W micro-hydro operating when it is rainy, with this I hope to never need the generator.
For forklift use they say to equalize once a week, that is with bigger drawdowns than I will be having. My plan is to equalize once a month as I have been before. With full sun (most days) my solar panels charge at around 100 amps and the batteries are floating by 1 PM doing an equalization charge is no problem. I believe there is a trade-off between sulphation/stratification and plate life due to higher temperatures/corrosion.
The watering system is nice but in a way is pointless as the specific gravity should be checked regularly anyway. To do that you have to pop the caps off, my old battery bank is lots of old golf cart batteries. Adding water to them was a real PITA as there are 216 cells (24 X 9), this new battery only has 24 cells so it will be much quicker.
Also I am very wary of the battery people saying tap is okay, we rely on rain water for the house. Even that has dust in it and metal ions from the house roof the same as water from a AC.
My watering system is Flow-Rite and the caps have a little hole with a rubber plug that swings off to the side of the hole. It allows for one of their hydrometer to be inserted in that hole to measure the SG without removing the caps.
With the prior set I did not have enough solar to mix up the electrolyte and thus they were undercharged and with Summer ambient heat typically 90-105 F batteries are in a pontoon but still get the heat of the day. They lasted 13 years before one cell became weak. Draw down was typically 10-20% so I think any thing around 15 years is good for typical life of fork lift type cells.
For the new cells I have more solar and equalize them for at least 2 hours every month, except winter Nov - March where I set the Classic to skip 3 days between Absorb cycle and use end Amps to terminate the Absorb early as to not over charge. Been in use for 5 years now and they all seem to be doing well, even with the heat. Nothing I can do about the heat so don't worry about it other than to temp comp the charging and if I get 15 years or more out of them I will be happy.
I am working on improving my setup with the AC so high temperatures will not be an issue when there is sufficient sun. The price of a small AC that draws 500 or 600W max is not much these days, then it should be no problem to keep the batteries in an environment of around 22 degrees. That should keep the batteries near 25 while charging, at present, I have all my solar equipment in a shipping container which is much harder to keep comfortable. One option I could do for now is put the batteries in an insulated box and let the vent fan draw air out of the box and have a inlet pipe directly from the outlet of the AC. Last summer I had one day that the Midnite CC recorded 45 degrees.
Quote from: ClassicCrazy on November 19, 2017, 10:57:10 AM
Seems like golden rule is never ever ever put anything but distilled water in a battery . That battery dealer either doesn't know much or has some very pure water !
Larry
Or wants to sell more batteries. That IS his business.
Definitely return those cells to their retaining steel tub!
As resthome stated you will get battery damage otherwise.
There is a exide dealer in brisbane mate.
Have you tried them?
I have some old 1330 amp exide cell tubs with the charging parameters on them.
Not perfect but better than nothing.
I am in qld and have my cells under cover with no a/c on them.
Temp rarely goes over 30deg.
Pm me if you want those charge levels.
It would give you a starting point.
Your batteries would be heavier and most likely take more and a tad higher charging.
It would be good to get those charge settings, should be no reason not to post them for everyone to see.
The battery arrived Friday afternoon and I managed to unload it in one piece and get it connected then. So it is still in its steel box, it was sitting on 50.7 volts when I got it. It has not been below 50V yet according to the Midnite monitoring, state of charge has only been down to 87%. The people I bought them from are waiting for the factory in India to send them the settings, I will give them a call today to see if there has been any progress.
(//)
That metal ruler on top of the batteries- yikes !
Larry
All the terminals are insulated so it is not as bad as it first appears, it is resting on the case so it is not in contact with the batteries. But you are right it is not a good place for it.
Was a Nice Ruler !! Let me tell yar the close call !!
:-)
VT
There was no close call all the terminals and bolt heads are fully insulated, you could throw the ruler into the battery all day long and it would not short.
There is hole in the top of the insulator on the bolt head just large enough for a meter probe to fit in, there is no way you could get the ruler to make contact.
I get it but scares me all the same - when I am using metal tools like rachets or wrenches to work on my batteries I try to be extra careful just in case ! The thought of all that current running through a metal tool and it getting red hot - well keeps me conscious ! I was messing around with some small agm batteries ( like 30 ah or less ) once and was using some bare copper wire to buss all the terminals together to put a trickle charge in and accidentally touched the wire to other terminal and got a nice burn mark along my hand instantly !
Larry
I have had a similar experience with 18650 Lithium batteries, put one in backwards and got a nasty burn.
The manufacturer of the batteries this topic is about has done a very nice job with o-rings on the interconnector lugs to keep them safe from corrosion and the insulation on them and the bolts. They really have improved the safety in a big way, if it makes you feel any better I did hesitate and think is something better to use for scale in the photo, but there was nothing at hand other than the ruler. If this was a battery with lead links or similar I would never have put the ruler there.
Anyhow if anyone else wants to have a shot at me about the ruler go ahead I know it was safe and as far as I am concerned the subject is closed.
I didn't know all those terminals were insulated like that . That is a great . never seen that before .
Larry
I like the work they did to make it as safe as possible....
HOWEVER .... the cables that connect to the ? buss bar(s) do not appear to be or have a shrink fitted covering right to the final connection ie look at the blue Cable covering near the 150 mark on the ruler..
still a potential 'short-able connection'... just needs one of those cheap plastic/rubber covers used on cars etc these days..
Quote from: BioPower on November 27, 2017, 02:50:27 AM
Anyhow if anyone else wants to have a shot at me about the ruler go ahead I know it was safe and as far as I am concerned the subject is closed.
I was NOT having a shot @ you Sir.
I was making a Joke !!
We have all been there & it's why we know how to treat POWER
I use Hot gloves on 600Vdc trolleys at one time in my life & hot sticks up service poles / buckets .
It was typed & posted for a funny only .
Im now opening up EV battery packs of 200 to 540 VDC ni mh or Li ion or Li Po cells .
MAN you need to be alert & with it ..
VT
Sorry if I pd Ya
Sorry VT I took your comments the wrong way, it is difficult to see the smile on your face when you type those kinds of comments. ;)
No Worries Mate ;)
Sparkie On
VT :-)
Cig lighter was used till we all stopped carry one .
Then they brought out the mini ones !
Metric or Imperial ruler ;)
http://midniteftp.com/forum/index.php?action=dlattach;topic=3908.0;attach=6259;image
Metric I C .
Neat setup on the posts , but on these EV cells I find many that have corrosion on the buss-bars from the NIMH ones with the alkaline electrolyte . This could be the reason they were taken out of service .Voltage drops .
So since you need to disassemble the cells / pack to move them (like me changing the structure lay out ) I am on my final build , using SDG (Silicone Dielectric Grease )on all with stainless 316 bolts & nuts . They had copper bars steel nuts & cadmium plated washers , no wonder they were having a problem . Green bars & corrosion nuts .