It'd be nice if UPSes had a balancing system akin to how lithium batteries have with the taps between cells to make sure they're all charged properly, but I guess that'd make them cost more, and APC would not make the big bucks out of selling us over-priced battery packs that crap out in no time due to not being properly charged...
I had an 48V sine wave ups which used 4 batteries in series. I added simple circuits to each battery consisting of a suitable zener diode and a 250R resistor. All components were cherry-picked from a larger batch to be close to identical. The batteries lasted over 6 years until one dried out. No puffy overheated cells and no drama. I keep telling myself that the balancing circuit helped :)
This one's a really good heads up! Had to learn this the hard way by buying new batteries every two years before this matter came to my mind. Now have been rocking the same cheap batteries on the same UPS for five years now (and counting), all was needed was to individually charge them first so they were balanced from the get go.
I just picked up some used 52v 18650 packs. First thing I did was open them up and make sure every parallel bank was the same voltage. This helps out the bms plus verifies the bms has been working.
We use the exact same batteries in our fire panels 2 in series. And we (of course) never balance them. And we test them every year by letting the panels run on batteries for over 1 hour (+- 1A load) and after one hour they never differ more than a few 1/100 of a volt. I guess they kind of balance themselves.
hmmm, I thought charging to 14.8v per cell is what gets them into balance? whatever is over 13.7v is just a temporary charge and whatever is extra current flowing just electrolises the water? So the higher charged one just electrolises the water a little more absorbing nothing more than it can hold and passing the current to the other battery getting it to the same voltage. maybe the UPS never does that for a long enough time perhaps? well I guess I better check and charge my UPS's then, and will certainly keep that in mind in the future!
Interesting, got 3 years out of my previous 2x12v 18ah batteries, I wonder if I could have extended them by checking this first? I also brought a new UPS this time instead of just batteries, do you think UPS manufacturers check this or just throw two batteries in off the shelf? Next lot I will need to do this however, appreciate the knowledge and content! :)
Hello, I want to ask about this device. Model No.: InfiniSolar 10k - PAR - B Does it sell the surplus to the electricity network? I own 2 of these devices. According to your experience, is it possible to earn, meaning is there a feature to export surplus electricity to the local network? Please answer
Edit: Do not take the numbers in my post as fact. Read the reply and do your own research. What about the internal differences between the cells? I guess a balance charge (if I remember the terminology) of 18 or so volts (don't know the procedure by heart, only by word of mouth from UA-cam) would be a good idea for all lead acid batteries, new and then ever so often... Right? It's a serious question that has been nagging me for years.
18 V on a 12 V block is WAY WAY WAY TOO MUCH DON'T DO IT! You want to use a low current constant current charge or a 14.8-14.9 V constant voltage charge for a couple of hours at most. On more serious batteries you get specs to follow. But none of them go up to 18 V ;) For example, on the Sonnenschein A600 Solar, you push 1.2 A per 100 Ah through the battery for 4 hours to balance it.
This is indeed important, I always bring out my adjustable PSU's as well when I get new or used batteries and just let them all charge fully before even considering using them :) Also we use the same solder, yay :D
It’s amazing how much money and frustrating time wasted would have been saved if people actually read the manual on battery set up in the first place. Usually batteries just don’t go and die early deaths all by themselves because they’re defective. It’s usually the person who installed them murdered the batteries.
You can't do more than this; by doing an equalising charge, you try to charge all of them up to 100 %. The fewer cells in series you have while doing this, the less damage you'll do to them.
That is definitely not always the case, I see cases all the time where one battery floats at 13.5 V and the other at 14,1, and they just never really recover. This is especially true when you get two batteries from different batches, which is a frequent enough occurence.
@@FFcossag that means one of them is cooked. It will never recover no matter what you do. The capacity in the one that never recovers is at most half oh the other one. This is why it happens, and the other reason is a huge voltage difference, like 12.8 vs 11.0 or something like that. You have the tools, do an experiment with batteries having the same tested capacity and if i am wrong, i will send you flowers and two boxes of candy! :)))
The company I work for, go through 100's batteries of these in a year that get wired in series and I've never seen a problem with them being unbalanced. The biggest killer of these batteries is heat. They only have a service life of 5yrs because they produce hydrogen sulfide.
ROFL @ _"go through 100's batteries of these in a year that get wired in series and I've never seen a problem"_ - well of course, because you aren't looking for a problem.
@@johncoops6897 I've been working on fire alarms & 24v PSU's for over 15yrs and I've never seen a problem with unbalanced batteries. I have the proper tester for these batteries so you soon see if the batteries are out of spec. When you do the annual inspection that involves testing over 400 batteries in a two weeks on one site, you soon start to see patterns of battery failure. Usually it's either cheap rubbish batteries or heat. Heat kills these batteries faster than anything else. In a room that's constantly over 27'C batteries that are good for 5+ years can be killed in less than 2.
@@FFcossag It's not a big problem, it's usually prevented by regular testing and replacing them before they go out of capacity spec. I can usually spot them if look at the way the light reflects off the sides. If they are convex in any way, then it's time to swap them out. It can happen quicker if the terminals corrode.
@@grahammuppet - sounds like you've never even tested them for voltage balance. Nevertheless, they kind-of "self-balance" to a degree if you whack them with a very low current charge for a long period of time. What kills them is heat, vibration, and being continually trickle charged (like UPS tend to do).
i have so many questions !! first what are you going to do with them and second did you check the amount of liquid inside ?? maybe the capacity difference is due to the amount liquid inside and can you top it up or not (i bought new led acid batterys before for my car and found it had low amount of acid ....... from factory )
They're just for a little UPS I have by the servers, in case the GFCI trips or something, so they can shut down gracefully. You can't check the water level in AGMs. If you open them, all you see is a moist fiberglass mat between the cells, there's no "level".
This video should be titled: _Why you should individually charge _*_ALL_*_ new batteries before install_ . The exact same thing is vital for any battery chemistry where the cells are in Series. Some people think that Lithium BMS can "balance" but often the balance current is so small that it never catches up.
It'd be nice if UPSes had a balancing system akin to how lithium batteries have with the taps between cells to make sure they're all charged properly, but I guess that'd make them cost more, and APC would not make the big bucks out of selling us over-priced battery packs that crap out in no time due to not being properly charged...
I had an 48V sine wave ups which used 4 batteries in series. I added simple circuits to each battery consisting of a suitable zener diode and a 250R resistor. All components were cherry-picked from a larger batch to be close to identical. The batteries lasted over 6 years until one dried out. No puffy overheated cells and no drama. I keep telling myself that the balancing circuit helped :)
This one's a really good heads up! Had to learn this the hard way by buying new batteries every two years before this matter came to my mind. Now have been rocking the same cheap batteries on the same UPS for five years now (and counting), all was needed was to individually charge them first so they were balanced from the get go.
I just picked up some used 52v 18650 packs. First thing I did was open them up and make sure every parallel bank was the same voltage. This helps out the bms plus verifies the bms has been working.
We use the exact same batteries in our fire panels 2 in series. And we (of course) never balance them. And we test them every year by letting the panels run on batteries for over 1 hour (+- 1A load) and after one hour they never differ more than a few 1/100 of a volt. I guess they kind of balance themselves.
hmmm, I thought charging to 14.8v per cell is what gets them into balance? whatever is over 13.7v is just a temporary charge and whatever is extra current flowing just electrolises the water? So the higher charged one just electrolises the water a little more absorbing nothing more than it can hold and passing the current to the other battery getting it to the same voltage. maybe the UPS never does that for a long enough time perhaps? well I guess I better check and charge my UPS's then, and will certainly keep that in mind in the future!
I always put them in parallel and charge them at 1amp..
Interesting, got 3 years out of my previous 2x12v 18ah batteries, I wonder if I could have extended them by checking this first?
I also brought a new UPS this time instead of just batteries, do you think UPS manufacturers check this or just throw two batteries in off the shelf?
Next lot I will need to do this however, appreciate the knowledge and content! :)
The manufacturers definitely do not check this.
Hello, I want to ask about this device.
Model No.: InfiniSolar 10k - PAR - B
Does it sell the surplus to the electricity network? I own 2 of these devices. According to your experience, is it possible to earn, meaning is there a feature to export surplus electricity to the local network? Please answer
You can, but you need to talk to your local grid operator and sign a contract, if they offer it.
Edit: Do not take the numbers in my post as fact. Read the reply and do your own research.
What about the internal differences between the cells? I guess a balance charge (if I remember the terminology) of 18 or so volts (don't know the procedure by heart, only by word of mouth from UA-cam) would be a good idea for all lead acid batteries, new and then ever so often... Right?
It's a serious question that has been nagging me for years.
18 V on a 12 V block is WAY WAY WAY TOO MUCH DON'T DO IT! You want to use a low current constant current charge or a 14.8-14.9 V constant voltage charge for a couple of hours at most. On more serious batteries you get specs to follow. But none of them go up to 18 V ;)
For example, on the Sonnenschein A600 Solar, you push 1.2 A per 100 Ah through the battery for 4 hours to balance it.
I wish I had your brain bro.
Heh, thanks, and you're getting little bits and pieces of it thorugh these videos!
This is indeed important, I always bring out my adjustable PSU's as well when I get new or used batteries and just let them all charge fully before even considering using them :) Also we use the same solder, yay :D
I was taught many decades ago to put 500k resistors across batteries in series and let them balance themselves..
It'd literally take forever with a 500k resistor!
If one pack was at 12V and one was at 6V, you would be "balancing" at 12 MICRO Amperes.
It’s amazing how much money and frustrating time wasted would have been saved if people actually read the manual on battery set up in the first place.
Usually batteries just don’t go and die early deaths all by themselves because they’re defective. It’s usually the person who installed them murdered the batteries.
This just sucks bad, when the UPS in question uses 64x 12v packs...
RIP. It might be more economical to just replace them on a schedule than actually testing them.
Aren't the cells in series inside individual batteries, too? What to do about them?
You can't do more than this; by doing an equalising charge, you try to charge all of them up to 100 %. The fewer cells in series you have while doing this, the less damage you'll do to them.
Please , can you tell me what is the cut-off current for battery charging : Ex : for lead acid 12V 7.2A
That depends on many, many factors. 0,01C-0,05 works as a rule of thumb.
@@FFcossag Thank you
yeah, but no :))) . put them in series and you will see they will get even in about 20-30 min. you are doing some utter wasting of time.
That is definitely not always the case, I see cases all the time where one battery floats at 13.5 V and the other at 14,1, and they just never really recover. This is especially true when you get two batteries from different batches, which is a frequent enough occurence.
@@FFcossag that means one of them is cooked. It will never recover no matter what you do. The capacity in the one that never recovers is at most half oh the other one. This is why it happens, and the other reason is a huge voltage difference, like 12.8 vs 11.0 or something like that. You have the tools, do an experiment with batteries having the same tested capacity and if i am wrong, i will send you flowers and two boxes of candy! :)))
The company I work for, go through 100's batteries of these in a year that get wired in series and I've never seen a problem with them being unbalanced. The biggest killer of these batteries is heat. They only have a service life of 5yrs because they produce hydrogen sulfide.
Hydrogen sulfide? I haven't heard much about that being an issue in VRLAs, can you tell me more?
ROFL @ _"go through 100's batteries of these in a year that get wired in series and I've never seen a problem"_ - well of course, because you aren't looking for a problem.
@@johncoops6897 I've been working on fire alarms & 24v PSU's for over 15yrs and I've never seen a problem with unbalanced batteries. I have the proper tester for these batteries so you soon see if the batteries are out of spec. When you do the annual inspection that involves testing over 400 batteries in a two weeks on one site, you soon start to see patterns of battery failure. Usually it's either cheap rubbish batteries or heat. Heat kills these batteries faster than anything else. In a room that's constantly over 27'C batteries that are good for 5+ years can be killed in less than 2.
@@FFcossag It's not a big problem, it's usually prevented by regular testing and replacing them before they go out of capacity spec. I can usually spot them if look at the way the light reflects off the sides. If they are convex in any way, then it's time to swap them out. It can happen quicker if the terminals corrode.
@@grahammuppet - sounds like you've never even tested them for voltage balance. Nevertheless, they kind-of "self-balance" to a degree if you whack them with a very low current charge for a long period of time.
What kills them is heat, vibration, and being continually trickle charged (like UPS tend to do).
i have so many questions !! first what are you going to do with them and second did you check the amount of liquid inside ?? maybe the capacity difference is due to the amount liquid inside and can you top it up or not (i bought new led acid batterys before for my car and found it had low amount of acid ....... from factory )
They're just for a little UPS I have by the servers, in case the GFCI trips or something, so they can shut down gracefully.
You can't check the water level in AGMs. If you open them, all you see is a moist fiberglass mat between the cells, there's no "level".
This video should be titled:
_Why you should individually charge _*_ALL_*_ new batteries before install_ .
The exact same thing is vital for any battery chemistry where the cells are in Series. Some people think that Lithium BMS can "balance" but often the balance current is so small that it never catches up.